Computational simulations and experimental validation of structure- physicochemical properties of pristine and functionalized graphene: Implications for adverse effects on p53 mediated DNA damage response. Basheer Faiza,Melge Anu R,Sasidharan Abhilash,Nair Shantikumar V,Manzoor K,Mohan C Gopi International journal of biological macromolecules Recent reports indicated DNA damaging potential of few-layer graphene in human cell systems. Here, we used computational technique to understand the interaction of both pristine (pG) or carboxyl functionalized graphene (fG) of different sizes (1, 6, and 10nm) with an important DNA repair protein p53. The molecular docking study revealed strong interaction between pG and DNA binding domains (DBD) of p53 with binding free energies (BE) varying from -12.0 (1nm) to -34 (6nm)kcal/mol, while fG showed relatively less interaction with BE varying from -6.7 (1nm) to -11.1 (6nm)kcal/mol. Most importantly, pG or fG bound p53-DBDs could not bind to DNA. Further, microarray analysis of human primary endothelial cells revealed graphene intervention on DNA damage and its structure-properties effect using comet assay studies. Thus, computational and experimental results revealed the structure-physicochemical property dependent adverse effects of graphene in DNA repair protein p53. 10.1016/j.ijbiomac.2017.10.106
    Remote nongenetic optical modulation of neuronal activity using fuzzy graphene. Rastogi Sahil K,Garg Raghav,Scopelliti Matteo Giuseppe,Pinto Bernardo I,Hartung Jane E,Kim Seokhyoung,Murphey Corban G E,Johnson Nicholas,San Roman Daniel,Bezanilla Francisco,Cahoon James F,Gold Michael S,Chamanzar Maysam,Cohen-Karni Tzahi Proceedings of the National Academy of Sciences of the United States of America The ability to modulate cellular electrophysiology is fundamental to the investigation of development, function, and disease. Currently, there is a need for remote, nongenetic, light-induced control of cellular activity in two-dimensional (2D) and three-dimensional (3D) platforms. Here, we report a breakthrough hybrid nanomaterial for remote, nongenetic, photothermal stimulation of 2D and 3D neural cellular systems. We combine one-dimensional (1D) nanowires (NWs) and 2D graphene flakes grown out-of-plane for highly controlled photothermal stimulation at subcellular precision without the need for genetic modification, with laser energies lower than a hundred nanojoules, one to two orders of magnitude lower than Au-, C-, and Si-based nanomaterials. Photothermal stimulation using NW-templated 3D fuzzy graphene (NT-3DFG) is flexible due to its broadband absorption and does not generate cellular stress. Therefore, it serves as a powerful toolset for studies of cell signaling within and between tissues and can enable therapeutic interventions. 10.1073/pnas.1919921117
    Fluorescent biosensors enabled by graphene and graphene oxide. Zhang Huan,Zhang Honglu,Aldalbahi Ali,Zuo Xiaolei,Fan Chunhai,Mi Xianqiang Biosensors & bioelectronics During the past few years, graphene and graphene oxide (GO) have attracted numerous attentions for the potential applications in various fields from energy technology, biosensing to biomedical diagnosis and therapy due to their various functionalization, high volume surface ratio, unique physical and electrical properties. Among which, graphene and graphene oxide based fluorescent biosensors enabled by their fluorescence-quenching properties have attracted great interests. The fluorescence of fluorophore or dye labeled on probes (such as molecular beacon, aptamer, DNAzymes and so on) was quenched after adsorbed on to the surface of graphene. While in the present of the targets, due to the strong interactions between probes and targets, the probes were detached from the surface of graphene, generating dramatic fluorescence, which could be used as signals for detection of the targets. This strategy was simple and economy, together with great programmable abilities of probes; we could realize detection of different kinds of species. In this review, we first briefly introduced the history of graphene and graphene oxide, and then summarized the fluorescent biosensors enabled by graphene and GO, with a detailed account of the design mechanism and comparison with other nanomaterials (e.g. carbon nanotubes and gold nanoparticles). Following that, different sensing platforms for detection of DNAs, ions, biomolecules and pathogens or cells as well as the cytotoxicity issue of graphene and GO based in vivo biosensing were further discussed. We hope that this review would do some help to researchers who are interested in graphene related biosening research work. 10.1016/j.bios.2016.07.030
    Shock Exfoliation of Graphene Fluoride in Microwave. Wu Sicheng,Mo Jingxin,Zeng Yachao,Wang Yuan,Rawal Aditya,Scott Jason,Su Zhen,Ren Wenhao,Chen Sheng,Wang Kaixuan,Chen Wei,Zhang Yongzhi,Zhao Chuan,Chen Xianjue Small (Weinheim an der Bergstrasse, Germany) An unprecedented microwave-based strategy is developed to facilitate solid-phase, instantaneous delamination and decomposition of graphite fluoride (GF) into few-layer, partially fluorinated graphene. The shock reaction occurs (and completes in few seconds) under microwave irradiation upon exposing GF to either "microwave-induced plasma" generated in vacuum or "catalyst effect" caused by intense sparking of graphite at ambient conditions. A detailed analysis of the structural and compositional transformations in these processes indicates that the GF experiences considerable exfoliation and defluorination, during which sp -bonded carbon is partially recovered despite significant structural defects being introduced. The exfoliated fluorinated graphene shows excellent electrochemical performance as anode materials in potassium ion batteries and as catalysts for the conversion of O to H O . This simple and scalable method requires minimal energy input and does not involve the use of other chemicals, which is attractive for extensive research in fluorine-containing graphene and its derivatives in laboratories and industrial applications. 10.1002/smll.201903397
    Graphene Surfaces Interaction with Proteins, Bacteria, Mammalian Cells, and Blood Constituents: The Impact of Graphene Platelet Oxidation and Thickness. Henriques Patrícia C,Pereira Andreia T,Pires Ana L,Pereira André M,Magalhães Fernão D,Gonçalves Inês C ACS applied materials & interfaces Graphene-based materials (GBMs) have been increasingly explored for biomedical applications. However, interaction between GBMs-integrating surfaces and bacteria, mammalian cells, and blood components, that is, the major biological systems in our body, is still poorly understood. In this study, we systematically explore the features of GBMs that most strongly impact the interactions of GBMs films with plasma proteins and biological systems. Films produced by vacuum filtration of GBMs with different oxidation degree and thickness depict different surface features: graphene oxide (GO) and few-layer GO (FLGO) films are more oxidized, smoother, and hydrophilic, while reduced GO (rGO) and few-layer graphene (FLG) are less or nonoxidized, rougher, and more hydrophobic. All films promote glutathione oxidation, although in a lower extent by rGO, indicating their potential to induce oxidative stress in biological systems. Human plasma proteins, which mediate most of the biological interactions, adsorb less to oxidized films than to rGO and FLG. Similarly, clinically relevant bacteria, , , , and , adhere less to GO and FLGO films, while rGO and FLG favor bacterial adhesion and viability. Surface features caused by the oxidation degree and thickness of the GBMs powders within the films have less influence toward human foreskin fibroblasts; all materials allow cell adhesion, proliferation and viability up to 14 days, despite less on rGO surfaces. Blood cells adhere to all films, with higher numbers in less or nonoxidized surfaces, despite none having caused hemolysis (<5%). Unlike thickness, oxidation degree of GBMs platelets strongly impact surface morphology/topography/chemistry of the films, consequently affecting protein adsorption and thus bacteria, fibroblasts and blood cells response. Overall, this study provides useful guidelines regarding the choice of the GBMs to use in the development of surfaces for an envisioned application. Oxidized materials appear as the most promising for biomedical applications that require low bacterial adhesion without being cytotoxic to mammalian cells. 10.1021/acsami.9b21841
    A chemiresistive biosensor based on a layered graphene oxide/graphene composite for the sensitive and selective detection of circulating miRNA-21. Huang Chi-Hsien,Huang Tzu-Ting,Chiang Chia-Heng,Huang Wei-Ting,Lin Yi-Ting Biosensors & bioelectronics In this study we developed a uniform, large-area, layered graphene composite of graphene oxide/graphene (GO/G) for the detection of circulating miRNA-21, a reliable biomarker for early cancer diagnosis. We prepared this layered composite of GO/G through low-damage plasma treatment of bilayer G. The top layer of G was oxidized (i.e., atomic layer oxidation) to form a GO layer, which acted as the bio-receptor, while retaining the properties of the bottom layer of G, which acted as an electrical response medium. With this structure, we fabricated a simple chemiresistive biosensor that could detect miRNA-21. The electrical resistance of the sensor varied linearly (R = 0.986) with respect to concentrations of the target miRNA-21 in the range from 10 pM to 100 nM in phosphate-buffered saline (PBS); the limit of detection was 14.6 pM. Hall measurements revealed that the mobility and concentration of the hole carriers both decreased upon increasing the target concentration, leading to the measured increase in resistivity of our chemiresistive biosensor. Furthermore, the sensor could discriminate the complementary target miRNA-21 from its single- and four-base-mismatched counterparts and another non-complementary miRNA. The ability to detect miRNA-21 in human serum albumin and bovine serum albumin was almost identical to that in PBS. 10.1016/j.bios.2020.112320
    Effect of graphene quantum dot size on plant growth. Xu Yao,Lu Yihua,Li Jiagen,Liu Rulin,Zhu Xi Nanoscale We found a straightforward dependence of plant growth on the sizes of graphene quantum dots. Enormous GQDs, such as graphene with dimensions of micrometers, neither promoted nor inhibited the growth. In contrast, synthesized GQDs with dimensions of about 10 nm best promoted the plant growth. Moreover GQDs synthesized using an "intelligent" chemistry robot yielded even better growth results than did GQDs synthesized conventionally by humans. In addition, a theoretical model was derived for the mechanism of the promotion of plant growth by GQDs. 10.1039/d0nr01913e
    Free-standing graphene oxide mid-infrared polarizers. Zheng Xiaorui,Xu Bing,Li Shuo,Lin Han,Qiu Ling,Li Dan,Jia Baohua Nanoscale Mid-infrared (MIR) represents a crucial spectral region for applications in spectroscopy, sensing, imaging, security and industry screening, owing to the strong characteristic vibrational transitions of many important molecules. However, the current MIR compatible materials are fragile, hazardous, and costly, which hampers the performance of MIR devices. Here, we developed a versatile transmittance-based Kramers-Kronig method and obtained the optical properties of graphene oxide in the MIR region, unveiling its application potentials as a novel MIR compatible material. As an example, we demonstrated free-standing graphene oxide MIR polarizers with large extinction ratio (∼20 dB) and controllable working wavelength up to 25 μm, by using the low-cost and flexible direct laser writing technique. Our transmittance-based KK method offers a versatile approach to obtain the optical properties of novel atomic-scale low-dimensional materials in the less developed MIR region and opens up opportunities in high performing functional MIR devices. 10.1039/d0nr01619e
    Facile and Ultraclean Graphene-on-Glass Nanopores by Controlled Electrochemical Etching. Zhang Xiaoyan,van Deursen Pauline M G,Fu Wangyang,Schneider Grégory F ACS sensors A wide range of approaches have been explored to meet the challenges of graphene nanostructure fabrication, all requiring complex and high-end nanofabrication platform and suffering from surface contaminations, potentially giving electrical noise and increasing the thickness of the atomically thin graphene membrane. Here, with the use of an electrical pulse on a low-capacitance graphene-on-glass (GOG) membrane, we fabricated clean graphene nanopores on commercially available glass substrates with exceptionally low electrical noise. liquid AFM studies and electrochemical measurements revealed that both graphene nanopore nucleation and growth stem from the electrochemical attack on carbon atoms at defect sites, ensuring the creation of a graphene nanopore. Strikingly, compared to conventional TEM drilled graphene nanopores on SiN supporting membranes, GOG nanopores featured an order-of-magnitude reduced broadband noise, which we ascribed to the electrochemical refreshing of graphene nanopore on mechanically stable glass chips with negligible parasitic capacitance (∼1 pF). Further experiments on double-stranded DNA translocations demonstrated a greatly reduced current noise, and also confirmed the activation of single nanopores. Therefore, the exceptionally low noise and ease of fabrication will facilitate the understanding of the fundamental property and the application of such atomically thin nanopore sensors. 10.1021/acssensors.0c00883
    Graphene oxide and graphene oxide functionalized with silver nanoparticles as adsorbents of phosphates in waters. A comparative study. Vicente-Martínez Y,Caravaca M,Soto-Meca A,De Francisco-Ortiz O,Gimeno F The Science of the total environment Phosphate removal is an important factor that must be taken into account in eutrophized waters. For this reason, many studies on different ways of removing phosphates from water have been published nowadays. In this work, a comparative study between the use of graphene oxide (GO) and graphene oxide functionalized with silver nanoparticles (GO@AgNPs) as adsorbents to remove phosphates from water samples has been carried out. Experimental conditions, including the pH, adsorbent dose, contact time and temperature, have been analyzed to achieve the highest adsorption efficiency. Although both adsorbents can be considered suitable for removing phosphates from aqueous solutions, GO@AgNPs provided a maximum removal efficiency of 100%, reaching the equilibrium conditions instantaneously under straightforward experimental conditions. Moreover, a much lower adsorbent dose was necessary than with graphene oxide. When GO was used, the maximum removal efficiency was 75%, 9 min were necessary to reach the equilibrium conditions and 20 mg of adsorbent were needed. Both adsorbents can be regenerated in an acid medium, giving recovery percentages of 98% and 80% for GO and GO@AgNPs respectively, which allows them to be recycled and used again. 10.1016/j.scitotenv.2019.136111
    Planar graphene/h-BN/graphene heterostructures for protein stretching and confinement. He Zhi,Zhou Ruhong Nanoscale Protein stretching and confinement in nanochannels is critical for advancing single-molecule detection techniques. For standard nanochannels integrated with nano-sensors, reducing their cross-section is beneficial for reading highly localized signals with minimal error, but results in increasing difficulty for the initial capture of any chain molecules due to the entropy barrier. Using molecular dynamics simulations, we show that spontaneous protein stretching can be realized by a two-dimensional (2D) heterostructure composed of a hexagonal boron nitride (h-BN) nanoribbon stitched with two graphene (GRA) sheets (i.e., a sandwiched GRA/BN/GRA structure). Due to fast protein diffusion on its flat surface and adsorption potential difference between two 2D materials, this planar nanochannel permits effective capture and elongation of three representative intrinsically disordered proteins including amyloid-β (1-42), polyglutamine (42) and α-synuclein (61-95). Moreover, we found that the extremely narrow h-BN stripe can provide stronger confinement for a longer polyglutamine chain after being stretched. Our approach has the potential to facilitate the bona fide readout of single-molecule protein sequencing techniques. 10.1039/d0nr02271c
    Potential interference with microtubule assembly by graphene: a tug-of-war. Luan Binquan,Cheng Shengfeng Nanoscale With the ever-increasing demand for graphene-based materials and their promising applications in numerous nanotechnologies, the biological effects of graphene on living systems have become crucial and ought to be well understood. Previously, both the cytotoxicity of graphene towards biological cells and its potential application as a nanomedicine have been revealed experimentally and theoretically. Besides many existing anticancer drugs that target microtubules, here we investigate the possibility of using graphene as a nanomedicine, which could alter the dynamic assembly and disassembly of a microtubule. We found that when a graphene nanosheet is at the hydrophilic interface of two neighboring heterodimers (containing α and β tubulins), it can pull one dimer away from the other through a "tug-of-war" mechanism, driven by the strong dispersive interaction exerted by the surface of the graphene nanosheet. This work demonstrates that based on the existing methods for mitigating graphene's cytotoxicity (already developed in this field), a graphene-based nanomedicine could be designed to target microtubules of cancer cells and induce cell apoptosis. 10.1039/c9nr10234e
    Graphene nanosheets as reinforcement and cell-instructive material in soft tissue scaffolds. Tiwari Sanjay,Patil Rahul,Dubey Sunil K,Bahadur Pratap Advances in colloid and interface science Mechanical strength of polymeric scaffolds deteriorates quickly in the physiological mileu. This can be minimized by reinforcing the polymeric matrix with graphene, a planar two-dimensional material with unique physicochemical and biological properties. Association between the sheet and polymer chains offers a range of porosity commensurate with tissue requirements. Besides, studies suggest that corrugated structure of graphene offers desirable bio-mechanical cues for tissue regeneration. This review covers three important aspects of graphene-polymer composites, (a) the opportunity on reinforcing the polymer matrix with graphene, (b) challenges associated with limited aqueous processability of graphene, and (c) physiological signaling in the presence of graphene. Among numerous graphene materials, our discussion is limited to graphene oxide (GO) and reduced graphene oxide (rGO) nanosheets. Challenges associated with limited dispersity of hydrophobic sheets within the polymeric matrix have been discussed at molecular level. 10.1016/j.cis.2020.102167
    Direct 3D printing of graphene using capillary suspensions. Ding Hui,Barg Suelen,Derby Brian Nanoscale Conventional 3D printing of graphene requires either a complex formulation of the ink with large quantities of polymers or essential post-processing steps such as freeze drying to allow printability. Here we present a graphene capillary suspension (GCS) containing 16.67 wt% graphene nanoparticles in aqueous suspension with 3.97 wt% carboxymethyl cellulose (CMC) as a stabiliser and a small quantity of the immiscible liquid octanol. This is shown to have the appropriate rheological properties for 3D printing, which is demonstrated through the fabrication of a simple lattice structure by direct writing and air drying at room temperature. The printed structure has a porosity of 81%, is robust for handling with a compression strength of 1.3 MPa and has an electrical conductivity of 250 S m. After heat treatment at 350 °C conductivity is 2370 S m but the strength reduces to 0.4 MPa. X-Ray tomography of the internal architecture after printing shows the formation of the capillary suspension eliminates ordering of the 2D materials during extrusion through the printer nozzle. Thus capillary suspensions can be used to direct write graphene 3D structures without the necessity of complicated drying steps or burn-out of large quantities of polymer additions, facilitating shape retention and property control as compared to current 2D material ink formulations used for 3D printing. 10.1039/c9nr10831a
    Creation of a two-dimensional polymer and graphene heterostructure. Wang Honglei,Yang Jing,Zhao Pei,Gölzhäuser Armin,Liu Wei,Chen Xudong,Zheng Zhikun Nanoscale van der Waals (vdW) heterostructures generated by stacking of graphene with other two-dimensional (2D) crystalline sheets have produced a new class of "designer" materials which shows great promise for nanoscience and nanotechnology. However, the 2D sheets are obtained either from nature or synthesized by high-energy procedures, which preclude the design of their structures as well as properties from molecular design on demand. Here, we introduced a rationally designed 2D polymer (one-monomer unit thick, freestanding network composed of periodically linked monomers) as a component for heterostructure construction, and created a 2D polymer-graphene heterostructure. The heterostructure has a high chemical stability, and could be thermally stable up to 400 °C. In the heterostructure, the 2D polymer doped graphene without changing its intrinsic structure, leading to the enhancement of its electric conductivity by a factor of ∼2.5. This piece of work opens the door to tune the properties of graphene heterostructures with rational design for specific applications. 10.1039/c9nr10858k
    Recent Advances of Porous Graphene: Synthesis, Functionalization, and Electrochemical Applications. Zhang Yuanyuan,Wan Qijin,Yang Nianjun Small (Weinheim an der Bergstrasse, Germany) Graphene is a 2D sheet of sp bonded carbon atoms and tends to aggregate together, due to the strong π-π stacking and van der Waals attraction between different layers. Its unique properties such as a high specific surface area and a fast mass transport rate are severely blocked. To address these issues, various kinds of 2D holey graphene and 3D porous graphene are either self-assembled from graphene layers or fabricated using graphene related materials such as graphene oxide and reduced graphene oxide. Porous graphene not only possesses unique pore structures, but also introduces abundant exposed edges and accelerates mass transfer. The properties and applications of these porous graphenes and their composites/hybrids have been extensively studied in recent years. Herein, recent progress and achievements in synthesis and functionalization of various 2D holey graphene and 3D porous graphene are reviewed. Of special interest, electrochemical applications of porous graphene and its hybrids in the fields of electrochemical sensing, electrocatalysis, and electrochemical energy storage, are highlighted. As the closing remarks, the challenges and opportunities for the future research of porous graphene and its composites are discussed and outlined. 10.1002/smll.201903780
    Nitrogen-doped graphene quantum dots prepared by electrolysis of nitrogen-doped nanomesh graphene for the fluorometric determination of ferric ions. Yang Fan,Bao Weijie,Liu Tianxing,Zhang Bing,Huang Shuo,Yang Wang,Li Yun,Li Na,Wang Chunxia,Pan Caiwen,Li Yongfeng Mikrochimica acta Nitrogen-doped graphene quantum dots (N-GQDs) were synthesized by direct electrolysis of a carbon cloth electrode coated with nitrogen-doped nanomesh graphene (NG) in high yield (~ 25%). The N-GQDs emit intense blue fluorescence with a quantum yield (QY) of 10% ± 3%. Meanwhile, the N-GQDs are rich in hydroxyl, carboxyl, basic pyridinic nitrogen, and nitro groups, which are conducive to strengthen the interaction between N-GQDs and Fe for highly sensitive determination of Fe ions. Specifically, the determination for Fe was conducted at different concentrations of N-GQD solution with a wide linear range of 10-1000 μM (150 μg·mL) and a low detection limit of 0.19 μM (10 μg·mL). Moreover, the fluorescence quenching mechanism illustrated that the functional groups generated by electrochemical oxidation enhanced the interaction of N-GQDs and Fe, and the narrow band gap (2.83 eV) of N-GQDs accomplished electron transfer from N-GQDs to Fe easily. Graphical abstract A highly conductive carbon cloth electrode coated with nitrogen-doped nanomesh graphene (NG) was developed to prepared nitrogen-doped graphene quantum dots (N-GQDs) which was endowed with a wide linear range from 10 to 1000 μM (150 μg/mL) and a low detection limit of 0.19 μM (10 μg/mL) in the determination of Fe. 10.1007/s00604-020-04294-8
    Integration of Graphene Electrodes with 3D Skeletal Muscle Tissue Models. Kim Yongdeok,Pagan-Diaz Gelson,Gapinske Lauren,Kim Yerim,Suh Judy,Solomon Emilia,Harris Jennifer Foster,Nam SungWoo,Bashir Rashid Advanced healthcare materials Integration of conductive electrodes with 3D tissue models can have great potential for applications in bioelectronics, drug screening, and implantable devices. As conventional electrodes cannot be easily integrated on 3D, polymeric, and biocompatible substrates, alternatives are highly desirable. Graphene offers significant advantages over conventional electrodes due to its mechanical flexibility and robustness, biocompatibility, and electrical properties. However, the transfer of chemical vapor deposition graphene onto millimeter scale 3D structures is challenging using conventional wet graphene transfer methods with a rigid poly (methyl methacrylate) (PMMA) supportive layer. Here, a biocompatible 3D graphene transfer method onto 3D printed structure using a soft poly ethylene glycol diacrylate (PEGDA) supportive layer to integrate the graphene layer with a 3D engineered ring of skeletal muscle tissue is reported. The use of softer PEGDA supportive layer, with a 10 times lower Young's modulus compared to PMMA, results in conformal integration of the graphene with 3D printed pillars and allows electrical stimulation and actuation of the muscle ring with various applied voltages and frequencies. The graphene integration method can be applied to many 3D tissue models and be used as a platform for electrical interfaces to 3D biological tissue system. 10.1002/adhm.201901137
    Complex three-dimensional graphene structures driven by surface functionalization. Ho Duc Tam,Ho Viet Hung,Babar Vasudeo,Kim Sung Youb,Schwingenschlögl Udo Nanoscale The origami technique can provide inspiration for fabrication of novel three-dimensional (3D) structures with unique material properties from two-dimensional sheets. In particular, transformation of graphene sheets into complex 3D graphene structures is promising for functional nano-devices. However, practical realization of such structures is a great challenge. Here, we introduce a self-folding approach inspired by the origami technique to form complex 3D structures from graphene sheets using surface functionalization. A broad set of examples (Miura-ori, water-bomb, helix, flapping bird, dachshund dog, and saddle structure) is achieved via molecular dynamics simulations and density functional theory calculations. To illustrate the potential of the origami approach, we show that the graphene Miura-ori structure combines super-compliance, super-flexibility (both in tension and compression), and negative Poisson's ratio behavior. 10.1039/d0nr01733g
    Nanophase graphene frameworks. Liu Jinxin,Wang Luyang,Da Yumin,Li Liang,Ruan Xuefeng,Zeng Mengqi,Fu Lei Nanoscale Nanophase graphene frameworks (NGFs) assembled by interconnected domains have massive interfaces, where the interfacial interaction and the compact architectures drastically elevate the durability of graphene towards physical and chemical destruction. The excellent electrical conductivity of the NGFs can be perfectly maintained even after 1500 friction cycles or 3 h flame treatment. 10.1039/c9nr02281c
    Defect-assisted protein HP35 denaturation on graphene. Gu Zonglin,Song Wei,Chen Serena H,Li Baoyu,Li Weifeng,Zhou Ruhong Nanoscale Structural defects in nanomaterials can alter their physical and chemical properties including magnetization, electronic and thermal conductivities, light absorption, and emission capabilities. Here, we investigated the potential impact of these defects on their biological effects through molecular dynamics simulations. By modeling the interaction between a graphene nanosheet and a widely used model protein, the chicken villin headpiece subdomain (HP35), we observed severe protein denaturation upon contact with defective graphene, while the protein remained intact on ideal graphene. The enhanced toxicity of defective graphene was due to the stronger attraction of the surface residues of HP35 from the defect edges (represented by carboxyl groups in our simulations) than from the ideal graphene. Upon binding to defective graphene, the contacting residues were restrained near the defective sites, which acted as "anchors" for the adsorbed protein. The "anchors" subsequently caused the protein to expose its aromatic and hydrophobic core residues to the graphene surface, via strong π-π stacking and hydrophobic interactions, thus leading to the unfolding of the protein. These findings not only highlight the importance of defects in nanomaterials' impact on biological systems, but also provide insights into fine-tuning the potential biological properties of nanomaterials through defect engineering. 10.1039/c9nr01143a
    DNA Hybridization Measured with Graphene Transistor Arrays. Mensah Kokoura,Cissé Ismaïl,Pierret Aurélie,Rosticher Michael,Palomo José,Morfin Pascal,Plaçais Bernard,Bockelmann Ulrich Advanced healthcare materials Arrays of field-effect transistors are fabricated from chemical vapor deposition grown graphene (GFETs) and label-free detection of DNA hybridization performed down to femtomolar concentrations. A process is developed for large-area graphene sheets, which includes a thin Al O layer, protecting the graphene from contamination during photolithographic patterning and a SiO capping for biocompatibility. It enables fabrication of high-quality transistor arrays, exhibiting stable close-to-zero Dirac point voltages under ambient conditions. Passivation of the as-fabricated chip with a layer composed of two different oxides avoids direct electrochemical contact between the DNA solutions and the graphene layer during hybridization detection. DNA probe molecules are electrostatically immobilized via poly-l-lysine coating of the chip surface. Adsorption of this positively charged polymer induces a positive shift of the Dirac point and subsequent immobilization of negatively charged DNA probes induces a negative shift. Spatially resolved hybridization of DNA sequences is performed on the GFET arrays. End-point as well as real-time in situ measurements of hybridization are achieved. A detection limit of 10 fm is observed for hybridization of 20-nucleotide DNA targets. Typical voltage signals are around 100 mV and spurious drifts below 1 mV per hour. 10.1002/adhm.202000260
    Microfluidic Printing of Three-Dimensional Graphene Electroactive Microfibrous Scaffolds. Qing Huaibin,Ji Yuan,Li Wenfang,Zhao Guoxu,Yang Qingzhen,Zhang Xiaohui,Luo Zhengtang,Lu Tian Jian,Jin Guorui,Xu Feng ACS applied materials & interfaces Graphene materials have attracted special attention because of their electrical conductivity, mechanical properties, and favorable biocompatibility. Although various methods have been developed for fabricating micro/nano conductive fibrous scaffolds, it is still challenging to fabricate the three-dimensional (3D) graphene fibrous scaffolds. Herein, we developed a new method, termed as microfluidic 3D printing technology (M3DP), to fabricate 3D graphene oxide (GO) microfibrous scaffolds with an adjustable fiber length, fiber diameter, and scaffold structure by integrating the microfluidic spinning technology with a programmable 3D printing system. GO microfibrous scaffolds were then transformed into conductive reduced graphene oxide (rGO) microfibrous scaffolds by hydrothermal reduction. Our results demonstrated that the fabricated 3D fibrous graphene scaffolds exhibited tunable structures, maneuverable mechanical properties, and good electrical conductivity and biocompatibility, as reflected by the adhesion and proliferation of SH-SY5Y cells on the graphene microfibrous scaffolds in an obviously oriented manner. The developed M3DP would be a powerful tool for fabricating 3D graphene microfibrous scaffolds for electroactive tissue regeneration and drug-screening applications. 10.1021/acsami.9b17948
    Graphene-Enabled Adaptive Infrared Textiles. Ergoktas M Said,Bakan Gokhan,Steiner Pietro,Bartlam Cian,Malevich Yury,Ozden-Yenigun Elif,He Guanliang,Karim Nazmul,Cataldi Pietro,Bissett Mark A,Kinloch Ian A,Novoselov Kostya S,Kocabas Coskun Nano letters Interactive clothing requires sensing and display functionalities to be embedded on textiles. Despite the significant progress of electronic textiles, the integration of optoelectronic materials on fabrics remains as an outstanding challenge. In this Letter, using the electro-optical tunability of graphene, we report adaptive optical textiles with electrically controlled reflectivity and emissivity covering the infrared and near-infrared wavelengths. We achieve electro-optical modulation by reversible intercalation of ions into graphene layers laminated on fabrics. We demonstrate a new class of infrared textile devices including display, yarn, and stretchable devices using natural and synthetic textiles. To show the promise of our approach, we fabricated an active device directly onto a t-shirt, which enables long-wavelength infrared communication via modulation of the thermal radiation from the human body. The results presented here provide complementary technologies which could leverage the ubiquitous use of functional textiles. 10.1021/acs.nanolett.0c01694
    Pristine graphene induces innate immune training. Lebre Filipa,Boland John B,Gouveia Pedro,Gorman Aoife L,Lundahl Mimmi L E,I Lynch Roisin,O'Brien Fergal J,Coleman Jonathan,Lavelle Ed C Nanoscale Graphene-based materials are of increasing interest for their potential use in biomedical applications. However, there is a need to gain a deeper understanding of how graphene modulates biological responses before moving towards clinical application. Innate immune training is a recently described phenomenon whereby cells of the innate immune system are capable of being programmed to generate an increased non-specific response upon subsequent challenge. This has been well established in the case of certain microbes and microbial products. However, little is known about the capacity of particulate materials, such as pristine graphene (pGr), to promote innate immune training. Here we report for the first time that while stimulation with pGr alone does not directly induce cytokine secretion by bone-marrow derived macrophages (BMDMs), it programs them for enhanced secretion of proinflammatory cytokines (IL-6, TNF-α) and a concomitant decrease in production of the regulatory cytokine, IL-10 after Toll-like receptor (TLR) ligand stimulation. This capacity of pGr to program cells for enhanced inflammatory responses could be overcome if the nanomaterial is incorporated in a collagen matrix. Our findings thus demonstrate the potential of graphene to modulate innate immunity over long timescales and have implications for the design and biomedical use of pGr-based materials. 10.1039/c9nr09661b
    Imaging Andreev Reflection in Graphene. Bhandari Sagar,Lee Gil-Ho,Watanabe Kenji,Taniguchi Takashi,Kim Philip,Westervelt Robert M Nano letters Coherent charge transport along ballistic paths can be introduced into graphene by Andreev reflection, for which an electron reflects from a superconducting contact as a hole, while a Cooper pair is transmitted. We use liquid-helium cooled scanning gate microscopy (SGM) to image Andreev reflection in graphene in the magnetic focusing regime, where carriers move along cyclotron orbits between contacts. Images of flow are obtained by deflecting carrier paths and displaying the resulting change in conductance. When electrons enter the superconductor, Andreev-reflected holes leave for the collecting contact. To test the results, we destroy Andreev reflection with a large current and by heating above the critical temperature. In both cases, the reflected carriers change from holes to electrons. 10.1021/acs.nanolett.0c00903
    Electronic states of graphene nanoribbons and analytical solutions. Wakabayashi Katsunori,Sasaki Ken-Ichi,Nakanishi Takeshi,Enoki Toshiaki Science and technology of advanced materials Graphene is a one-atom-thick layer of graphite, where low-energy electronic states are described by the massless Dirac fermion. The orientation of the graphene edge determines the energy spectrum of π-electrons. For example, zigzag edges possess localized edge states with energies close to the Fermi level. In this review, we investigate nanoscale effects on the physical properties of graphene nanoribbons and clarify the role of edge boundaries. We also provide analytical solutions for electronic dispersion and the corresponding wavefunction in graphene nanoribbons with their detailed derivation using wave mechanics based on the tight-binding model. The energy band structures of armchair nanoribbons can be obtained by making the transverse wavenumber discrete, in accordance with the edge boundary condition, as in the case of carbon nanotubes. However, zigzag nanoribbons are not analogous to carbon nanotubes, because in zigzag nanoribbons the transverse wavenumber depends not only on the ribbon width but also on the longitudinal wavenumber. The quantization rule of electronic conductance as well as the magnetic instability of edge states due to the electron-electron interaction are briefly discussed. 10.1088/1468-6996/11/5/054504
    Local Carbon Concentration Determines the Graphene Edge Structure. Li Da,Wang Yanchao,Cui Tian,Ma Yanming,Ding Feng The journal of physical chemistry letters Although the structures and properties of various graphene edges have attracted enormous attention, the underlying mechanism that determines the appearance of various edges is still unknown. Here, a global search of graphene edge structures is performed by using the particle swarm optimization algorithm. In addition to locating the most stable edges of graphene, two databases of graphene armchair and zigzag edge structures are built. Graphene edge self-passivation plays an important role in the stability of the edges of graphene, and self-passivated edge structures that contain both octagons and triangles are found for the first time. The obvious "apical dominance" feature of armchair edges is found. The appearance of the experimentally observed ac(56), ac(677), and Klein edges can be explained by the local carbon concentration. Additionally, the graphene edge database is also significant for the study of the open end of nanotubes or fullerenes. 10.1021/acs.jpclett.0c00525
    Photoresponse in a Strain-Induced Graphene Wrinkle Superlattice. Sun Ruo-Xuan,Guo Qin-Qin,Guo Hao-Wei,Yan Xiao-Qing,Liu Zhi-Bo,Tian Jian-Guo The journal of physical chemistry letters Applied strain introduces significant changes in the carbon-carbon bond of graphene and thereby forms electronic superlattices. The electron/phonon coupling and existence of pseudogauge fields within these superlattices render unique electronic and magnetism properties. However, the interfacial interactions between strained and pristine graphene have rarely been studied. Herein, we report a prominent increase in photocurrent at the interface between pristine graphene and the strain-induced superlattice (i.e., the graphene wrinkle). The photocurrent distribution indicates a large increase in the bending lattice of graphene. These results demonstrate that the photocurrent enhancement is due to the difference in the Seebeck coefficient between pristine graphene and deformed superlattices, resulting in a significant increase in the photothermoelectric effect at the interface. 10.1021/acs.jpclett.0c01535
    Investigation of the Oxidation Behavior of Graphene/Ge(001) Versus Graphene/Ge(110) Systems. Akhtar Fatima,Dabrowski Jaroslaw,Lisker Marco,Yamamoto Yuji,Mai Andreas,Wenger Christian,Lukosius Mindaugas ACS applied materials & interfaces The oxidation behavior of Ge(001) and Ge(110) surfaces underneath the chemical vapor deposition (CVD)-grown graphene films has been investigated experimentally and interpreted on the basis of ab initio calculations. Freshly grown samples were exposed to air for more than 7 months and periodically monitored by X-ray photoelectron spectroscopy, scanning electron microscopy, and Raman spectroscopy. The oxidation of Ge(110) started with incubation time of several days, during which the oxidation rate was supposedly exponential. After an ultrathin oxide grew, the oxidation continued with a slow but constant rate. No incubation was detected for Ge(001). The oxide thickness was initially proportional to the square root of time. After 2 weeks, the rate saturated at a value fivefold higher than that for Ge(110). We argue that after the initial phase, the oxidation is limited by the diffusion of oxidizing species through atomic-size openings at graphene domain boundaries and is influenced by the areal density and by the structural quality of the boundaries, whereby the latter determines the initial behavior. Prolonged exposure affected the surface topography and reduced the strain in graphene. In the last step, both the air-exposed samples were annealed in vacuum at 850 °C. This removed oxygen from the substrate and restored the samples to their initial state. These findings might constitute an important step toward further optimization of graphene grown on Ge. 10.1021/acsami.9b18448
    Self-degrading graphene sheets for tumor therapy. Donskyi Ievgen S,Chen Ying,Nickl Philip,Guday Guy,Qiao Haishi,Achazi Katharina,Lippitz Andreas,Unger Wolfgang E S,Böttcher Christoph,Chen Wei,Adeli Mohsen,Haag Rainer Nanoscale Low biodegradability of graphene derivatives and related health risks are the main limiting factors for their in vivo biomedical applications. Here, we present the synthesis of enzyme-functionalized graphene sheets with self-degrading properties under physiological conditions and their applications in tumor therapy. The synergistic enzyme cascade glucose oxidase and myeloperoxidase are covalently conjugated to the surface of graphene sheets and two-dimensional (2D) platforms are obtained that can produce sodium hypochlorite from glucose. The enzyme-functionalized graphene sheets with up to 289 nm average size are degraded into small pieces (≤40 nm) by incubation under physiological conditions for 24 h. Biodegradable graphene sheets are further loaded with doxorubicin and their ability for tumor therapy is evaluated in vitro and in vivo. The laser-triggered release of doxorubicin in combination with the enzymatic activity of the functionalized graphene sheets results in a synergistic antitumor activity. Taking advantage of their neutrophil-like activity, fast biodegradability, high photo- and chemotherapeutic effects, the novel two-dimensional nanoplatforms can be used for tumor therapeutic applications. 10.1039/d0nr02159h
    Antimicrobial Mechanisms and Effectiveness of Graphene and Graphene-Functionalized Biomaterials. A Scope Review. Mohammed Hiba,Kumar Ajay,Bekyarova Elena,Al-Hadeethi Yas,Zhang Xixiang,Chen Mingguang,Ansari Mohammad Shahnawaze,Cochis Andrea,Rimondini Lia Frontiers in bioengineering and biotechnology Bacterial infections represent nowadays the major reason of biomaterials implant failure, however, most of the available implantable materials do not hold antimicrobial properties, thus requiring antibiotic therapy once the infection occurs. The fast raising of antibiotic-resistant pathogens is making this approach as not more effective, leading to the only solution of device removal and causing devastating consequences for patients. Accordingly, there is a large research about alternative strategies based on the employment of materials holding intrinsic antibacterial properties in order to prevent infections. Between these new strategies, new technologies involving the use of carbon-based materials such as carbon nanotubes, fullerene, graphene and diamond-like carbon shown very promising results. In particular, graphene- and graphene-derived materials (GMs) demonstrated a broad range antibacterial activity toward bacteria, fungi and viruses. These antibacterial activities are attributed mainly to the direct physicochemical interaction between GMs and bacteria that cause a deadly deterioration of cellular components, principally proteins, lipids, and nucleic acids. In fact, GMs hold a high affinity to the membrane proteoglycans where they accumulate leading to membrane damages; similarly, after internalization they can interact with bacteria RNA/DNA hydrogen groups interrupting the replicative stage. Moreover, GMs can indirectly determine bacterial death by activating the inflammatory cascade due to active species generation after entering in the physiological environment. On the opposite, despite these bacteria-targeted activities, GMs have been successfully employed as pro-regenerative materials to favor tissue healing for different tissue engineering purposes. Taken into account these GMs biological properties, this review aims at explaining the antibacterial mechanisms underlying graphene as a promising material applicable in biomedical devices. 10.3389/fbioe.2020.00465
    Graphene-based wearable sensors. Qiao Yancong,Li Xiaoshi,Hirtz Thomas,Deng Ge,Wei Yuhong,Li Mingrui,Ji Shourui,Wu Qi,Jian Jinming,Wu Fan,Shen Yang,Tian He,Yang Yi,Ren Tian-Ling Nanoscale The human body is a "delicate machine" full of sensors such as the fingers, nose, and mouth. In addition, numerous physiological signals are being created every moment, which can reflect the condition of the body. The quality and the quantity of the physiological signals are important for diagnoses and the execution of therapies. Due to the incompact interface between the sensors and the skin, the signals obtained by commercial rigid sensors do not bond well with the body; this decreases the quality of the signal. To increase the quantity of the data, it is important to detect physiological signals in real time during daily life. In recent years, there has been an obvious trend of applying graphene devices with excellent performance (flexibility, biocompatibility, and electronic characters) in wearable systems. In this review, we will first provide an introduction about the different methods of synthesis of graphene, and then techniques for graphene patterning will be outlined. Moreover, wearable graphene sensors to detect mechanical, electrophysiological, fluid, and gas signals will be introduced. Finally, the challenges and prospects of wearable graphene devices will be discussed. Wearable graphene sensors can improve the quality and quantity of the physiological signals and have great potential for health-care and telemedicine in the future. 10.1039/c9nr05532k
    Whole cell FRET immunosensor based on graphene oxide and graphene dot for Campylobacter jejuni detection. Dehghani Zahra,Mohammadnejad Javad,Hosseini Morteza,Bakhshi Bita,Rezayan Ali Hossein Food chemistry In this work a new fluorescence immunosensor with use of graphene oxide and graphene quantum dot for detection Campylobacter jejuni whole cell in food samples was designed. This biosensor was designed based on interaction of poly clonal antibody conjugated with graphene quantum dot with surface protein in Campylobacter jejuni cell membrane. Specific binding of graphene quantum dot with Campylobacter jejuni membrane leads to generate a distance among graphene dot and graphene oxide and fluorescence is ON. In lack of Campylobacter jejuni or in existence of other bacterial cells, distance between of graphene dot and graphene oxide is very low and graphene quantum dot fluorescence emission was OFF. Experiment revealed that step by step increase in bacterial target cells caused to gradually increased fluorescence emission and this process was linear. Limit of detection for this bacterial sensor was 10 CFU/ml and ability of this FRET immunosensor for Campylobacter jejuni sensing in comparison with other bacterial cells was significant. Also, this method for monitoring Campylobacter jejuni in poultry liver was applied and results revealed that this immunosensor could be used for analysis bacterial cell in food samples. 10.1016/j.foodchem.2019.125690
    Epitaxial graphene/Ge interfaces: a minireview. Dedkov Yuriy,Voloshina Elena Nanoscale The recent discovery of the ability to perform direct epitaxial growth of graphene layers on semiconductor Ge surfaces led to a huge interest in this topic. One of the reasons for this interest is the chance to overcome several present-day drawbacks on the method of graphene integration in modern semiconductor technology. The other one is connected with the fundamental studies of the new graphene-semiconductor interfaces that might help with the deeper understanding of mechanisms, which governs graphene growth on different substrates as well as shedding light on the interaction of graphene with these substrates, whose range is now spread from metals to insulators. The present minireview gives a timely overview of the state-of-the-art field of studies of the graphene-Ge epitaxial interfaces and draws some conclusions in this research area. 10.1039/d0nr00185f
    Ultrathin All-2D Lateral Graphene/GaS/Graphene UV Photodetectors by Direct CVD Growth. Chen Tongxin,Lu Yang,Sheng Yuewen,Shu Yu,Li Xuan,Chang Ren-Jie,Bhaskaran Harish,Warner Jamie H ACS applied materials & interfaces UV-sensitive lateral all-two-dimensional (2D) photodetecting devices are produced by growing the large band gap layered GaS between graphene electrode pairs directly using chemical vapor deposition methods. The use of prepatterned graphene electrode pairs on the Si wafer enables more than 200 devices to be fabricated simultaneously. We show that the surface chemistry of the substrate during GaS leads to selective growth in graphene gaps, forming the lateral heterostructures, rather than on the surface of graphene. The graphene/GaS/graphene lateral photodetecting devices are demonstrated to be sensitive to UV light only, with no measurable response to visible light. Furthermore, we demonstrate UV-band discrimination in photosensing, with measured photocurrents only produced for middle-UV and not for near-UV wavelength regions. The detection limit could reach down to 2.61 μW/cm with a photoresponsivity as high as 11.7 A/W and a photo gain of 53.7 under 270 nm excitation. Gate-dependent modulation of the photocurrent is also demonstrated. The photodetectors exhibit long-term stability and reproducible ON-OFF switching behavior, with a response time lower than 60 ms. These results provide insights into how ultrathin UV sensing devices can be created using only 2D materials by exploiting large band gap 2D semiconductors such as GaS. 10.1021/acsami.9b11984
    Photogating in the Graphene-Dye-Graphene Sandwich Heterostructure. Lee Youngbin,Kim Hyunmin,Kim Soo,Whang Dongmok,Cho Jeong Ho ACS applied materials & interfaces In this work, we developed an atomically thin (∼2.5 nm) heterostructure consisting of a monolayer rhodamine 6G (R6G) film as a photoactive layer that was sandwiched between graphene films functioning as channels (graphene-R6G-graphene, G-R-G). Through a comparison of results of both photocurrent measurements and chemically enhanced Raman scattering (CERS) experiments, we found that our G-R-G heterostructure exhibited ∼7 and ∼30 times better performance than R6G-attached single-graphene (R6G-graphene, R-G) and MoS devices, respectively; here, the CERS enhancement factor was highly correlated with the relative photoinduced Dirac voltage change. Furthermore, the photocurrent of the G-R-G device was found to be ∼40 times better than that of the R-G photodetector. The top graphene was highly operative in the monolayer, of which the performance is significantly deteriorated by fluorescence and tailored charge transfer efficiency with the increment of R6G film thickness. Overall, the responsivity of the G-R-G photodetector was ∼40 times higher than that of the R-G photodetector because of the more efficient carrier transfer between the organic dye and graphene induced by weaker π-π interactions between the top and bottom graphene channels in the former device. This atomically thin (∼2.5 nm) and highly photosensitive photodetector can be employed for post-Si-photodiode (PD) image sensors, single-photon detection devices, and optical communications. 10.1021/acsami.9b05280
    Ultratough graphene-black phosphorus films. Zhou Tianzhu,Ni Hong,Wang Yanlei,Wu Chao,Zhang Hao,Zhang Jianqi,Tomsia Antoni P,Jiang Lei,Cheng Qunfeng Proceedings of the National Academy of Sciences of the United States of America Graphene-based films with high toughness have many promising applications, especially for flexible energy storage and portable electrical devices. Achieving such high-toughness films, however, remains a challenge. The conventional mechanisms for improving toughness are crack arrest or plastic deformation. Herein we demonstrate black phosphorus (BP) functionalized graphene films with record toughness by combining crack arrest and plastic deformation. The formation of covalent bonding P-O-C between BP and graphene oxide (GO) nanosheets not only reduces the voids of GO film but also improves the alignment degree of GO nanosheets, resulting in high compactness of the GO film. After further chemical reduction and π-π stacking interactions by conjugated molecules, the alignment degree of rGO nanosheets was further improved, and the voids in lamellar graphene film were also further reduced. Then, the compactness of the resultant graphene films and the alignment degree of reduced graphene oxide nanosheets are further improved. The toughness of the graphene film reaches as high as ∼51.8 MJ m, the highest recorded to date. In situ Raman spectra and molecular dynamics simulations reveal that the record toughness is due to synergistic interactions of lubrication of BP nanosheets, P-O-C covalent bonding, and π-π stacking interactions in the resultant graphene films. Our tough black phosphorus functionalized graphene films with high tensile strength and excellent conductivity also exhibit high ambient stability and electromagnetic shielding performance. Furthermore, a supercapacitor based on the tough films demonstrated high performance and remarkable flexibility. 10.1073/pnas.1916610117
    Performance Degradation in Graphene-ZnO Barristors Due to Graphene Edge Contact. Kim So-Young,Ryou Junga,Kim Min Jae,Kim Kiyung,Lee Yongsu,Kim Seung-Mo,Hwang Hyeon Jun,Kim Yong-Hoon,Lee Byoung Hun ACS applied materials & interfaces The physical and chemical characteristics of the edge states of graphene have been studied extensively as they affect the electrical properties of graphene significantly. Likewise, the edge states of graphene in contact with semiconductors or transition-metal dichalcogenides (TMDs) are expected to have a strong influence on the electrical properties of the resulting Schottky junction devices. We found that the edge states of graphene form chemical bonds with the ZnO layer, which limits the modulation of the Fermi level at the graphene-semiconductor junction, in a manner similar to Fermi level pinning in silicon devices. Therefore, we propose that graphene-based Schottky contact should be accomplished with minimal edge contact to reduce the limits imposed on the Fermi level modulation; this hypothesis has been experimentally verified, and its microscopic mechanism is further theoretically examined. 10.1021/acsami.0c04325
    Chemical Route to Twisted Graphene, Graphene Oxide and Boron Nitride. Saraswat Aditi,Pramoda K,Debnath Koyendrila,Servottam Swaraj,Waghmare Umesh V,Rao C N R Chemistry (Weinheim an der Bergstrasse, Germany) The recently discovered twisted graphene has attracted considerable interest. A simple chemical route was found to prepare twisted graphene by covalently linking layers of exfoliated graphene containing surface carboxyl groups with an amine-containing linker (trans-1,4-diaminocyclohexane). The twisted graphene shows the expected selected area electron diffraction pattern with sets of diffraction spots out with different angular spacings, unlike graphene, which shows a hexagonal pattern. Twisted multilayer graphene oxide could be prepared by the above procedure. Twisted boron nitride, prepared by cross-linking layers of boron nitride (BN) containing surface amino groups with oxalic acid linker, exhibited a diffraction pattern comparable to that of twisted graphene. First-principles DFT calculations threw light on the structures and the nature of interactions associated with twisted graphene/BN obtained by covalent linking of layers. 10.1002/chem.202000277
    A review on recent advancements in electrochemical biosensing using carbonaceous nanomaterials. Sanati Alireza,Jalali Mahsa,Raeissi Keyvan,Karimzadeh Fathallah,Kharaziha Mahshid,Mahshid Sahar Sadat,Mahshid Sara Mikrochimica acta This review, with 201 references, describes the recent advancement in the application of carbonaceous nanomaterials as highly conductive platforms in electrochemical biosensing. The electrochemical biosensing is described in introduction by classifying biosensors into catalytic-based and affinity-based biosensors and statistically demonstrates the most recent published works in each category. The introduction is followed by sections on electrochemical biosensors configurations and common carbonaceous nanomaterials applied in electrochemical biosensing, including graphene and its derivatives, carbon nanotubes, mesoporous carbon, carbon nanofibers and carbon nanospheres. In the following sections, carbonaceous catalytic-based and affinity-based biosensors are discussed in detail. In the category of catalytic-based biosensors, a comparison between enzymatic biosensors and non-enzymatic electrochemical sensors is carried out. Regarding the affinity-based biosensors, scholarly articles related to biological elements such as antibodies, deoxyribonucleic acids (DNAs) and aptamers are discussed in separate sections. The last section discusses recent advancements in carbonaceous screen-printed electrodes as a growing field in electrochemical biosensing. Tables are presented that give an overview on the diversity of analytes, type of materials and the sensors performance. Ultimately, general considerations, challenges and future perspectives in this field of science are discussed. Recent findings suggest that interests towards 2D nanostructured electrodes based on graphene and its derivatives are still growing in the field of electrochemical biosensing. That is because of their exceptional electrical conductivity, active surface area and more convenient production methods compared to carbon nanotubes. Graphical abstract Schematic representation of carbonaceous nanomaterials used in electrochemical biosensing. The content is classified into non-enzymatic sensors and affinity/ catalytic biosensors. Recent publications are tabulated and compared, considering materials, target, limit of detection and linear range of detection. 10.1007/s00604-019-3854-2
    Understanding the influence of carbon nanomaterials on microbial communities. Chen Ming,Sun Yan,Liang Jie,Zeng Guangming,Li Zhongwu,Tang Lin,Zhu Yi,Jiang Danni,Song Biao Environment international Carbon nanomaterials (CNMs) are widely used because of their unique advantages in recent years. At the same time, the influence of CNMs on the environment is becoming increasingly prominent. This review mainly introduces the research progress in the effects of fullerenes, multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs) and graphene on microorganisms and their toxicity mechanisms. On this basis, we have analyzed beneficial and adverse effects of fullerenes, graphene, MWCNTs and SWCNTs to microorganisms, and discussed the similarities of the toxicity mechanisms of different CNMs on microorganisms. This review helps provide ideas on how to protect microorganisms from the impacts of carbon nanomaterials, and it will be conductive to providing a strong theoretical basis for better application of carbon nanomaterials. 10.1016/j.envint.2019.02.005
    How do proteins 'response' to common carbon nanomaterials? Wang Xianfeng,Zhu Yi,Chen Ming,Yan Ming,Zeng Guangming,Huang Danlian Advances in colloid and interface science Carbon nanomaterials are widely produced and applied in biological and environmental fields because of their outstanding physical and chemical properties, which pose a threat to the safety of living organisms and the ecological environment. Therefore, understanding how carbon nanomaterials and their derivatives work on organisms is becoming important. In recent years, more and more researchers have explored the damage of carbon nanomaterials to organisms at the molecular level. This review pays special emphasis on how proteins response to the main carbon nanomaterials (fullerene, carbon nanotubes, graphene and their derivatives). In addition, how to use the interaction between carbon nanomaterials and proteins to do some beneficial things for human and the development of safe nanomaterials is simply discussed. Finally, some suggestions have been made to lay a theoretical foundation for future research. 10.1016/j.cis.2019.06.002
    Synergistically Chemical and Thermal Coupling between Graphene Oxide and Graphene Fluoride for Enhancing Aluminum Combustion. Jiang Yue,Deng Sili,Hong Sungwook,Tiwari Subodh,Chen Haihan,Nomura Ken-Ichi,Kalia Rajiv K,Nakano Aiichiro,Vashishta Priya,Zachariah Michael R,Zheng Xiaolin ACS applied materials & interfaces Metal combustion reaction is highly exothermic and is used in energetic applications, such as propulsion, pyrotechnics, powering micro- and nano-devices, and nanomaterials synthesis. Aluminum (Al) is attracting great interest in those applications because of its high energy density, earth abundance, and low toxicity. Nevertheless, Al combustion is hard to initiate and progresses slowly and incompletely. On the other hand, ultrathin carbon nanomaterials, such as graphene, graphene oxide (GO), and graphene fluoride (GF), can also undergo exothermic reactions. Herein, we demonstrate that the mixture of GO and GF significantly improves the performance of Al combustion as interactions between GO and GF provide heat and radicals to accelerate Al oxidation. Our experiments and reactive molecular dynamics simulation reveal that GO and GF have strong chemical and thermal couplings through radical reactions and heat released from their oxidation reactions. GO facilitates the dissociation of GF, and GF accelerates the disproportionation and oxidation of GO. When the mixture of GO and GF is added to micron-sized Al particles, their synergistic couplings generate reactive oxidative species, such as CF and CFO, and heat, which greatly accelerates Al combustion. This work demonstrates a new area of using synergistic couplings between ultrathin carbon nanomaterials to accelerate metal combustion and potentially oxidation reactions of other materials. 10.1021/acsami.9b20397
    Functionalized 2D nanomaterials with switchable binding to investigate graphene-bacteria interactions. Tan Kok H,Sattari Shabnam,Donskyi Ievgen S,Cuellar-Camacho Jose L,Cheng Chong,Schwibbert Karin,Lippitz Andreas,Unger Wolfgang E S,Gorbushina Anna,Adeli Mohsen,Haag Rainer Nanoscale Graphene and its derivatives have recently attracted much attention for sensing and deactivating pathogens. However, the mechanism of multivalent interactions at the graphene-pathogen interface is not fully understood. Since different physicochemical parameters of graphene play a role at this interface, control over graphene's structure is necessary to study the mechanism of these interactions. In this work, different graphene derivatives and also zwitterionic graphene nanomaterials (ZGNMs) were synthesized with defined exposure, in terms of polymer coverage and functionality, and isoelectric points. Then, the switchable interactions of these nanomaterials with E. coli and Bacillus cereus were investigated to study the validity of the generally proposed "trapping" and "nano-knives" mechanisms for inactivating bacteria by graphene derivatives. It was found that the antibacterial activity of graphene derivatives strongly depends on the accessible area, i.e. edges and basal plane of sheets and tightness of their agglomerations. Our data clearly confirm the authenticity of "trapping" and "nano-knives" mechanisms for the antibacterial activity of graphene sheets. 10.1039/c8nr01347k
    Occupational exposure to graphene based nanomaterials: risk assessment. Pelin Marco,Sosa Silvio,Prato Maurizio,Tubaro Aurelia Nanoscale Graphene-based materials (GBMs) are a family of novel materials including graphene, few layer graphene (FLG), graphene oxide (GO), reduced graphene oxide (rGO) and graphene nanoplatelets (GNP). Currently, the risk posed by them to human health is associated mainly with the occupational exposure during their industrial and small-scale production or waste discharge. The most significant occupational exposure routes are inhalation, oral, cutaneous and ocular, inhalation being the majorly involved and most studied one. This manuscript presents a critical up-to-date review of the available in vivo toxicity data of the most significant GBMs, after using these exposure routes. The few in vivo inhalation toxicity studies (limited to 5-days of repeated exposure and only one to 5 days per week for 4 weeks) indicate inflammatory/fibrotic effects at the pulmonary level, not always reversible after 14/90 days. More limited in vivo data are available for the oral and ocular exposure routes, whereas the studies on cutaneous toxicity are at the initial stage. A long persistence of GBMs in rodents is recorded, while contradictory genotoxic data are reported. Data gap identification is also provided. Based on the available data, the occupational exposure limit cannot be determined. More experimental toxicity studies according to specific guidelines (tentatively validated for nanomaterials) and more information on the actual occupational exposure level to GBMs are needed. Furthermore, ADME (Absorption, Distribution, Metabolism, Excretion), genotoxicity, developmental and reproductive toxicity data related to the occupational exposure to GBMs have to be implemented. In addition, sub-chronic and/or chronic studies are still needed to completely exclude other toxic effects and/or carcinogenicity. 10.1039/c8nr04950e
    Interaction of graphene-family nanomaterials with microbial communities in sequential batch reactors revealed by high-throughput sequencing. Lian Shengyang,Qu Yuanyuan,Li Shuzhen,Zhang Zhaojing,Zhang Henglin,Dai Chunxiao,Deng Ye Environmental research The accelerated development and application of graphene-family nanomaterials (GFNs) have increased their release to various environments and converged in wastewater treatment plants (WWTPs). However, little is known about the interactions between GFNs and microbes in WWTPs. In this study, the interaction of graphene oxide (GO) or graphene (G) at different concentrations with microbial communities in sequential batch reactors was investigated. Transmission electron microscopy and Raman spectroscopy analyses showed that the structures of GFNs were obviously changed, which suggested GFNs could be degraded by some microbes. Significantly higher DNA concentration and lower cell number in high-concentration GO group were detected by DNA leakage test and qPCR analysis, which confirmed the microbial toxicity of GO. The chemical oxygen demand and ammonia nitrogen removals were significantly affected by G and GO with high concentrations. Further, high-throughput sequencing confirmed the composition and dynamic changes of microbial communities under GFNs exposure. Saccharibacteria genera incertae sedis (12.55-28.05%) and Nakamurella (20.45-29.30%) were the predominant genera at two stages, respectively. FAPROTAX suggested 12 functional groups with obvious changes related to the biogeochemical cycle of C, N and S. Molecular ecological network analysis showed that the networks were more complex in the presence of GFNs, and the increased negative interactions reflected more competition relationships in microbial communities. This study is the first to report the effect of GFNs on network of microbial communities, which provides in-depth insights into the complex and highlights concerns regarding the risk of GFNs to WWTPs. 10.1016/j.envres.2020.109392
    A review of graphene-based nanomaterials for removal of antibiotics from aqueous environments. Wang Xuandong,Yin Renli,Zeng Lixi,Zhu Mingshan Environmental pollution (Barking, Essex : 1987) Antibiotics as emerging pharmaceutical pollutants have seriously not only threatened human life and animal health security, but also caused environmental pollution. It has drawn enormous attention and research interests in the study of antibiotics removal from aqueous environments. Graphene, an interesting one-atom-thick, 2D single-layer carbon sheet with sp hybridized carbon atoms, has become an important agent for removal of antibiotic, owing to its unique physiochemical properties. Recently, a variety of graphene-based nanomaterials (GNMs) are reported to efficiently remove antibiotics from aqueous solutions by different technologies. In this review, we summarize different structure and properties of GNMs for the removal of antibiotics by adsorption. Meanwhile, advanced oxidation processes (AOPs), such as photocatalysis, Fenton process, ozonation, sulfate radical and combined AOPs by the aid of GNMs are summarized. Finally, the opportunities and challenges on the future scope of GNMs for removal of antibiotics from aqueous environments are proposed. 10.1016/j.envpol.2019.06.067
    Graphene family nanomaterials for application in cancer combination photothermal therapy. de Melo-Diogo Duarte,Lima-Sousa Rita,Alves Cátia G,Correia Ilídio J Biomaterials science Combining hyperthermia with other therapies holds a great potential for improving cancer treatment. In this approach, the increase in the body temperature can exert a therapeutic effect on cells and/or enhance the effectiveness of anticancer agents. However, the conventional methodologies available to induce hyperthermia cannot confine a high temperature increase to the tumor-site while maintaining healthy tissues unexposed and ensuring minimal invasiveness. To overcome these limitations, combination photothermal therapy (PTT) mediated by graphene family nanomaterials (GFN) has been showing promising results. Such is owed to the ability of GFN to accumulate at the tumor site and convert near infrared light into heat, enabling a hyperthermia with a high spatial-temporal resolution. Furthermore, GFN can also incorporate different therapeutic agents on their structure for delivery purposes to cancer cells. In this way, the combination PTT mediated by GFN can result in an improved therapeutic effect. In this review, the combination of GFN mediated PTT with chemo-, photodynamic-, gene-, radio-, and immuno-therapies is examined. Furthermore, the main parameters that influence these types of combination approaches are also analyzed, with emphasis on the photothermal potential of GFN and on the vascular and cellular effects produced by the temperature increase mediated by GFN. 10.1039/c9bm00577c
    A review on nanomaterial-based field effect transistor technology for biomarker detection. Syedmoradi Leila,Ahmadi Anita,Norton Michael L,Omidfar Kobra Mikrochimica acta Field effect transistor (FET) based sensors have attractive features such as small size, ease of mass production, high versatility and comparably low costs. Over the last decade, many FET type biosensors based on various nanomaterials (e.g. silicon nanowires, graphene, and transition metal dichalcogenides) have been developed to detect various classes of biomolecular targets due to their integration into portable and rapid test systems, both for use in the clinical lab and in point-of-care testing. This review (with 197 refs.) starts with an introduction into the specific features of FET biosensor technology. This is followed by a description of the essentials of methods for immobilization of recognition elements. The next section discusses the progress that has been made in FET based biosensors using semiconducting nanostructures composed of silicon, graphene, metal oxides, and transition metal dichalcogenides. A further section is devoted to microfluidic systems combined with FET biosensors. We then emphasize the biosensing applications of these diagnostic devices for analysis of clinically relevant biomarkers, specifically to sensing of neurotransmitters, metabolites, nucleic acids, proteins, cancer and cardiac biomarkers. Two tables are presented which summarize advances in applications of 1D and 2D nanomaterial-based FETs for biomarker sensing. A concluding section summarizes the current status, addresses current challenges, and gives perspective trends for the field. Graphical abstract Field effect transistor devices based on the use of 1D and 2D semiconductor nanostructures (so called nano-FETs) are making use of materials including silicon nanowires, graphene, zinc oxide, indium oxide, titanium oxide, and molybdenum disulfide that are further modified with recognition elements for biosensing application. 10.1007/s00604-019-3850-6
    Toxicology data of graphene-family nanomaterials: an update. Xiaoli Feng,Qiyue Chen,Weihong Guo,Yaqing Zhang,Chen Hu,Junrong Wu,Longquan Shao Archives of toxicology Due to its unique physical structure and chemical properties, graphene family nanomaterials (GFNs) and derived commodities have been widely used in commercial products, particularly biomedical applications, which has significantly increased the risk of human exposure. There exists significant evidence that GFNs are accumulated in a number of tissues and organs through different exposure pathways, and further cause toxicity manifested as lesions or functional impairment. Moreover, GFNs can be internalized by varing cell types and induce cytoskeletal disorders, organelle dysfunction, and interact directly with biological macromolecules such as DNA, mRNA and proteins, ultimately resulting in greater rates of cell apoptosis, necrosis and autophagic cell death. The toxicological effect of GFN is closely related to its lateral size, surface structure, functionalization, and propensity to adsorb proteins. Using major data published over the past four years, this review presents and summarizes state of current understanding of GFN toxicology and identifies current deficiencies and challenges. This review aims to help improve evaluation of the biocompatibility of GFNs and provides theoretical guidance for their safe application. 10.1007/s00204-020-02717-2
    Tailoring the component of protein corona via simple chemistry. Lu Xiang,Xu Peipei,Ding Hong-Ming,Yu You-Sheng,Huo Da,Ma Yu-Qiang Nature communications Control over the protein corona of nanomaterials allows them to function better. Here, by taking graphene/gold as examples, we comprehensively assessed the association of surface properties with the protein corona. As revealed by in vitro measurements and computations, the interaction between graphene/gold and HSA/IgE was inversely correlated with the hydroxyl group availability, whereas the interaction between that and ApoE was comparatively less relevant. Molecular simulations revealed that the number and the distribution of surface hydroxyl groups could regulate the manner in which nanomaterials interact with proteins. Moreover, we validated that ApoE pre-adsorption before injection enhances the blood circulation of nanomaterials relative to their pristine and IgE-coated counterparts. This benefit can be attributed to the invulnerability of the complementary system provided by ApoE, whose encasement does not increase cytotoxicity. Overall, this study offers a robust yet simple way to create protein corona enriched in dysopsonins to realize better delivery efficacy. 10.1038/s41467-019-12470-5
    Graphene nanoribbons: A promising nanomaterial for biomedical applications. Johnson Asha P,Gangadharappa H V,Pramod K Journal of controlled release : official journal of the Controlled Release Society Graphene nanoribbons (GNRs) are narrow lengthened strips of single-layer graphene. Among the graphene family of nanomaterials, GNRs are remarkable materials due to their attractive physical, chemical, electrical, mechanical, thermal, and optical properties. They have an ultra-high surface area. Graphene-oxide nanoribbons (GONRs), the oxygenated derivative of GNRs, offer more possibilities in the biomedicine due to their amphiphilic nature. Noncovalent and covalent modifications of these are possible for advanced biomedical applications. This review describes the properties, synthesis, surface modifications, and toxicities of GNRs, along with their biomedical applications. Their applications in drug delivery, anticancer therapy, sensing, antimicrobial therapy, imaging, gene therapy, photothermal therapy, management of spinal cord injury, bone regeneration, etc. are reviewed. 10.1016/j.jconrel.2020.06.034
    Graphene oxide-based materials for efficient removal of heavy metal ions from aqueous solution: A review. Liu Xiaolu,Ma Ran,Wang Xiangxue,Ma Yan,Yang Yongping,Zhuang Li,Zhang Sai,Jehan Riffat,Chen Jianrong,Wang Xiangke Environmental pollution (Barking, Essex : 1987) Graphene with atomic layer of sp-hybridized carbon atoms in a hexagonal structure has attracted multidisciplinary attention since its discovery. Due to the inherent advantages of large specific surface area and abundant functional groups, its derivative graphene oxide (GO) nanomaterials have achieved large-scale development in effective pollution treatment. In the past few years, novel GO-based nanomaterials through coupling with other nanomaterials have been synthesized with significant process and applied for efficient elimination of different kinds of pollutants. This paper aims to summarize recent research results on the excellent removal ability of GO-based nanomaterials for various heavy metal ions in aqueous solutions. The synthesis, adsorption process characteristics and interaction mechanism of the adsorbent are emphasized and discussed. The effects of various environmental conditions are outlined. At last, a brief summary, perspective and outlook are presented. This review is intended to provide some thrilling information for the design and manufacture of GO-based nanomaterials for the elimination of heavy metal ions from wastewater in environmental pollution management. 10.1016/j.envpol.2019.05.050
    Safety considerations for graphene: lessons learnt from carbon nanotubes. Bussy Cyrill,Ali-Boucetta Hanene,Kostarelos Kostas Accounts of chemical research Many consider carbon nanomaterials the poster children of nanotechnology, attracting immense scientific interest from many disciplines and offering tremendous potential in a diverse range of applications due to their extraordinary properties. Graphene is the youngest in the family of carbon nanomaterials. Its isolation, description, and mass fabrication has followed that of fullerenes and carbon nanotubes. Graphene's development and its adoption by many industries will increase unintended or intentional human exposure, creating the need to determine its safety profile. In this Account, we compare the lessons learned from the development of carbon nanotubes with what is known about graphene, based on our own investigations and those of others. Despite both being carbon-based, nanotubes and graphene are two very distinct nanomaterials. We consider the key physicochemical characteristics (structure, surface, colloidal properties) for graphene and carbon nanotubes at three different physiological levels: cellular, tissue, and whole body. We summarize the evidence for health effects of both materials at all three levels. Overall, graphene and its derivatives are characterized by a lower aspect ratio, larger surface area, and better dispersibility in most solvents compared to carbon nanotubes. Dimensions, surface chemistry, and impurities are equally important for graphene and carbon nanotubes in determining both mechanistic (aggregation, cellular processes, biodistribution, and degradation kinetics) and toxicological outcomes. Colloidal dispersions of individual graphene sheets (or graphene oxide and other derivatives) can easily be engineered without metallic impurities, with high stability and less aggregation. Very importantly, graphene nanostructures are not fiber-shaped. These features theoretically offer significant advantages in terms of safety over inhomogeneous dispersions of fiber-shaped carbon nanotubes. However, studies that directly compare graphene with carbon nanotubes are rare, making comparative considerations of their overall safety and risk assessment challenging. In this Account, we attempt to offer a set of rules for the development of graphene and its derivatives to enhance their overall safety and minimize the risks for adverse reactions in humans from exposure. These rules are: (1) to use small, individual graphene sheets that macrophages in the body can efficiently internalize and remove from the site of deposition; (2) to use hydrophilic, stable, colloidal dispersions of graphene sheets to minimize aggregation in vivo; and (3) to use excretable graphene material or chemically-modified graphene that can be degraded effectively. Such rules can only act as guidelines at this early stage in the development of graphene-based technologies, yet they offer a set of design principles for the fabrication and safe use of graphene material that will come in contact with the human body. In a broader context, the safety risks associated with graphene materials will be entirely dependent on the specific types of graphene materials and how they are investigated or applied. Therefore, generalizations about the toxicity of "graphene" as a whole will be inaccurate, possibly misleading, and should be avoided. 10.1021/ar300199e
    A label-free quantification method for measuring graphene oxide in biological samples. Xin Yan,Wan Bin Analytica chimica acta Characterization of carbonaceous nanomaterials (CNMs) exposure is a key step and of great importance towards a better understanding of their toxicity and underlying mechanisms. However, it has been bottlenecked for lack of valid methods capable of quantifying cell-associated CNMs. Here, we developed a new economical and convenient method based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) that could accumulate graphene oxide (GO) at the interface between the loading well and the gel. The sharp black band formed there can be digitalized and the intensity quantified, which was proportional to the amount of GO loaded onto the gel. The method has a detection limit of 84.1 ng. We showed that the amount of GO in three different cell models, mouse macrophage cells (Raw264.7), human epithelial cells (A549) and mouse mesenchymal stem cells (MSC), could be accurately quantified by this assay, with the uptake rates decreasing in the order of MSC > Raw264.7 > A549. The results were consistent with the fluorescent imaging on cells exposed to fluorescence-labeled GO and TEM examination on ultrathin cell sections. The surprisingly highest uptake rate of MSC might be due to their abundant intracellular vesicles, which deserves further investigation. The novel method provides a complementary quantitative tool to the use of radioactive markers and fluorescent labeling of carbon nanomaterials and may facilitate the toxicological studies on carbon nanomaterials. 10.1016/j.aca.2019.06.036
    Fast Identification and Quantification of Graphene Oxide in Aqueous Environment by Raman Spectroscopy. Yang Shengnan,Chen Qian,Shi Mengyao,Zhang Qiangqiang,Lan Suke,Maimaiti Tusunniyaze,Li Qun,Ouyang Peng,Tang Kexin,Yang Sheng-Tao Nanomaterials (Basel, Switzerland) Today, graphene nanomaterials are produced on a large-scale and applied in various areas. The toxicity and hazards of graphene materials have aroused great concerns, in which the detection and quantification of graphene are essential for environmental risk evaluations. In this study, we developed a fast identification and quantification method for graphene oxide (GO) in aqueous environments using Raman spectroscopy. GO was chemically reduced by hydrazine hydrate to form partially reduced GO (PRGO), where the fluorescence from GO was largely reduced, and the Raman signals (G band and D band) were dominating. According to the Raman characteristics, GO was easily be distinguished from other carbon nanomaterials in aqueous environments, such as carbon nanotubes, fullerene and carbon nanoparticles. The GO concentration was quantified in the range of 0.001-0.6 mg/mL with good linearity. Using our technique, we did not find any GO in local water samples. The transport of GO dispersion in quartz sands was successfully quantified. Our results indicated that GO was conveniently quantified by Raman spectroscopy after partial reduction. The potential applications of our technique in the environmental risk evaluations of graphene materials are discussed further. 10.3390/nano10040770
    Orientational DNA binding and directed transport on nanomaterial heterojunctions. Deng Ye,Wang Fuxin,Liu Yang,Yang Yanmei,Qu Yuanyuan,Zhao Mingwen,Mu Yuguang,Li Weifeng Nanoscale A deep understanding of the interactions between nanomaterials and biomolecules is critical for biomedical applications of nanomaterials. In this paper, we study the binding patterns, structural stabilities and diffusions of a double stranded DNA (dsDNA) segment on two recently reported graphene derivatives, boronic graphene (BC3) and nitrogenized graphene (C3N), with molecular dynamics (MD) simulations. Our results demonstrate that dsDNA exhibits a highly favored binding mode with an upright orientation on BC3 and C3N, independent of the initial configurations. In contrast to graphene (GRA) which demonstrates a cytotoxic feature, BC3 and C3N show high biocompatibility without causing evident structural distortions to the dsDNA duplex, benefitting from the periodic atomic charge distributions. Most interestingly, highly directional dsDNA transport is realized by formation of BC3/GRA and C3N/GRA in-plane heterojunctions, where the dsDNA migrating direction is uniformly BC3 → GRA → C3N. Furthermore, free energy profiling calculated by the umbrella sampling technique quantitatively supports these observations. Insights from our study would potentiate and guide future studies of graphenic 2D materials and bring about a flourishing new branch of in-plane heterojunction applications as targeted drug delivery templates in biomedical research. 10.1039/c9nr09166a
    The assembly of silk fibroin and graphene-based nanomaterials with enhanced mechanical/conductive properties and their biomedical applications. Li Kun,Li Ping,Fan Yubo Journal of materials chemistry. B Silk fibroin (SF), a natural protein biopolymer, exhibits a favorable structure due to the existence of alternative hydrophilic and hydrophobic domains in its molecular chains, and it shows good intrinsic mechanical properties, biocompatibility, biodegradability and low immunogenicity. The properties and functions of SF can be further enhanced and enriched through its synergetic combination with graphene-based nanomaterials (GBNs), which are two-dimensional carbon nanomaterials with impressive mechanical properties, adjustable electrical conductivity, and anticipated biocompatibility. The combination of SF and GBNs can result in fantastic properties and functions upon optimizing the interactions between them, and they can be processed into various formats to tailor them for specific applications. This review presents the structures and properties of SF and GBNs, summarizes recent progress related to assemblies of SF and GBNs, and then focuses on their interfacial interactions during the process of building high performance composites with good mechanical or conductive properties. The unique interactions provide potential ideas for designing novel composites of SF and GBNs with enhanced mechanical or conductive properties. Then, we provide the latest developments related to the applications of composites of SF and GBNs in different fields, emphasizing their applications in tissue engineering and wearable devices. Some challenges and potential measures are also suggested in relation to constructing composites of SF and GBNs to widen their future applications in biomedical fields. 10.1039/c9tb01733j
    Graphene-Based Nanomaterials for Flexible and Wearable Supercapacitors. Huang Liang,Santiago Diana,Loyselle Patricia,Dai Liming Small (Weinheim an der Bergstrasse, Germany) Along with the quick development of flexible and wearable electronic devices, there is an ever-growing demand for light-weight, flexible, and wearable power sources. Because of the high power density, excellent cycling stability and easy fabrication, flexible supercapacitors are widely studied for this purpose. Graphene-based nanomaterials are attractive electrode materials for flexible and wearable supercapacitors owing to their high surface area, good mechanical and electrical properties, and excellent electrochemical stability. The 2D structure and high aspect ratio of graphene nanosheets make them easy to assemble into films or fibers with good mechanical properties. In recent years, enormous progress has been made in developing flexible and wearable graphene-based supercapacitors. Here, the material and structure design strategies for developing film-shaped and emerging fiber-shaped flexible supercapacitors based on graphene nanomaterials are summarized. 10.1002/smll.201800879
    Multifunctional two dimensional BiSe nanodiscs for combined antibacterial and anti-inflammatory therapy for bacterial infections. Ouyang Jiang,Wen Mei,Chen Wansong,Tan Yanni,Liu Zhenjun,Xu Qunfang,Zeng Ke,Deng Liu,Liu You-Nian Chemical communications (Cambridge, England) A multifunctional platform based on two-dimensional nanomaterials for combined antibacterial and anti-inflammatory therapy is developed. Bi2Se3 nanodiscs selectively eradicate Gram-positive bacteria with a low risk of drug resistance. Moreover, Bi2Se3 nanodiscs with antioxidant activity relieve intracellular oxidative stress of macrophages to suppress inflammation caused by bacterial infections. 10.1039/c9cc01129c
    Refluxed Esterification of Fullerene-Conjugated P25 TiO Promotes Free Radical Scavenging Capacity and Facilitates Antiaging Potentials in Human Cells. Lee Kuen-Chan,Chen Yi-Lun,Wang Chien-Chen,Huang Jen-Hsien,Cho Er-Chieh ACS applied materials & interfaces Titanium dioxide nanomaterials have good capability to prevent human cells from damage under UV irradiation. However, some studies indicated that the nanoscale of titanium dioxide could potentially cause harmful effects such as free radical generation under UV irradiation and thereby accelerate the progress of cell aging. Fullerenes can scavenge large amounts of free radicals due to the fact that fullerenes contain enormous amount of π electrons with low lying lowest unoccupied molecular orbital, but its adverse properties, such as the poor solubility in water, restricted the applicability. In this study, we employed water-soluble carboxylic acid fullerenes (C-COOH and C-COOH) as the free radical scavenger and modify onto the surface of titanium dioxide by refluxed esterification (P25/C-COOH or C-COOH) technique. The conformation and properties of these nanomaterials were characterized by techniques and equipment such as X-ray diffraction, energy dispersive spectroscopy analysis, scanning electron microscopy, thermal gravimetric analysis, high-resolution transmission electron microscopy, and Fourier transform infrared spectroscopy. We also introduced methylene blue and rhodamine B as indicators to evaluate and demonstrate the scavenging capacity of these nanomaterials. Moreover, we examined the biocompatibility and UV protection capacity of our P25/fullerene composites in human 293T cells, and applied luciferase activity assay to investigate the possible underlying cell protection mechanisms exhibited by these nanomaterials. Our data indicate that both P25/C-COOH and P25/C-COOH could protect human cells against UV exposure. P25/C-COOH exhibits great anti-inflammation capacity, whereas P25/C-COOH exhibits great anti-oxidative stress and anti-DNA damage capacity. Our results suggest that most of our P25/fullerene composite materials have the ability to reduce free radicals and exhibit high biomedical potential in anti-inflammation, anti-oxidant, and anti-aging applications. 10.1021/acsami.8b18253
    Anti-Infective Application of Graphene-Like Silicon Nanosheets via Membrane Destruction. Luo Yao,Ge Min,Lin Han,He Renke,Yuan Xiangwei,Yang Chao,Wang Wei,Zhang Xianlong Advanced healthcare materials The increasing problem of bacterial resistance to the currently effective antibiotics has resulted in the need for increasingly potent therapeutics to eradicate pathogenic microorganisms. 2D nanomaterials (2D NMs) have unique physical and chemical properties that make them attractive candidates for biomedical applications. Recently, the application of 2D NMs as antibacterial agents has attracted significant attention. Herein, a novel 2D graphene-like silicon nanosheet (GS NS) antimicrobial agent is fabricated from pristine silicon crystals by ultrasonication, which results in a highly exfoliated planar morphology and a significantly larger surface area as compared with bulk silicon. The GS NSs exhibit remarkable in vitro broad-spectrum bactericidal activity against Gram (-) Escherichia coli and Gram (+) Staphylococcus aureus because of a close interaction with the bacteria, which leads to highly efficient membrane destruction. The in vivo studies demonstrate that the local administration of GS NSs effectively mitigates implant-related infection by reducing the bacterial burden of the extracted samples and accelerating the remission of local inflammation. Based on these encouraging results, GS NSs are expected to be a useful new member of the 2D NMs family, with the potential of effectively killing pathogenic bacteria in clinical applications. 10.1002/adhm.201901375
    Modulation of Macrophage Polarization for Bone Tissue Engineering Applications. Jamalpoor Zahra,Asgari Alireza,Lashkari Mohammad Hossein,Mirshafiey Abbas,Mohsenzadegan Monireh Iranian journal of allergy, asthma, and immunology Innate immune cells play a crucial role in bone development and repair. Macrophages are the main effector cells in immune responses to implants and are indispensable for bone healing success. The heterogeneity and plasticity of macrophages make them a prime target for immune system modulation to enhance bone repair and regeneration. It is believed that the polarization of macrophage phenotype towards the anti-inflammatory M2, rather than the inflammatory M1 phenotype, promotes osteogenesis. Tissue-engineered bioimplants are potentially capable of producing signals to modulate macrophage polarization. Therefore, development of smart immunomodulatory bioimplants via manipulation of their properties seem a promising strategy for tuning immune responses to optimize bone repair without any unwanted inflammatory reactions. The purpose of the present review is to summarize the currently available studies performed on the effects of macrophage polarization, especially towards M2 phenotype, both in bone repair and in bioimplant-stimulated osteogenesis. Moreover, this literature highlights the need to focus future studies on the development of smart immunomodulatory implants capable of switching macrophage polarization-enhancing bone implant-host tissue integration.
    Nano-particle mediated M2 macrophage polarization enhances bone formation and MSC osteogenesis in an IL-10 dependent manner. Mahon Olwyn R,Browe David C,Gonzalez-Fernandez Tomas,Pitacco Pierluca,Whelan Ian T,Von Euw Stanislas,Hobbs Christopher,Nicolosi Valeria,Cunningham Kyle T,Mills Kingston H G,Kelly Daniel J,Dunne Aisling Biomaterials Engineering a pro-regenerative immune response following scaffold implantation is integral to functional tissue regeneration. The immune response to implanted biomaterials is determined by multiple factors, including biophysical cues such as material stiffness, topography and particle size. In this study we developed an immune modulating scaffold for bone defect healing containing bone mimetic nano hydroxyapatite particles (BMnP). We first demonstrate that, in contrast to commercially available micron-sized hydroxyapatite particles, in-house generated BMnP preferentially polarize human macrophages towards an M2 phenotype, activate the transcription factor cMaf and specifically enhance production of the anti-inflammatory cytokine, IL-10. Furthermore, nano-particle treated macrophages enhance mesenchymal stem cell (MSC) osteogenesis in vitro and this occurs in an IL-10 dependent manner, demonstrating a direct pro-osteogenic role for this cytokine. BMnPs were also capable of driving pro-angiogenic responses in human macrophages and HUVECs. Characterization of immune cell subsets following incorporation of functionalized scaffolds into a rat femoral defect model revealed a similar profile, with micron-sized hydroxyapatite functionalized scaffolds eliciting pro-inflammatory responses characterized by infiltrating T cells and elevated expression of M1 macrophages markers compared to BMnP functionalized scaffolds which promoted M2 macrophage polarization, tissue vascularization and increased bone volume. Taken together these results demonstrate that nano-sized Hydroxyapatite has immunomodulatory potential and is capable of directing anti-inflammatory innate immune-mediated responses that are associated with tissue repair and regeneration. 10.1016/j.biomaterials.2020.119833
    Biomimetic anti-inflammatory nano-capsule serves as a cytokine blocker and M2 polarization inducer for bone tissue repair. Yin Chengcheng,Zhao Qin,Li Wu,Zhao Zifan,Wang Jinyang,Deng Tian,Zhang Peng,Shen Kailun,Li Zubing,Zhang Yufeng Acta biomaterialia Controlling of pro-inflammation induced by pro-inflammatory cytokines and anti-inflammatory response induced by M2 macrophages is important for osteogenesis in the process of bone tissue repair. Thus, we fabricated biomimetic anti-inflammatory nano-capsule (BANC) that can block cytokines and promote M2 macrophage polarization, presenting a positive role for bone tissue repair. The BANC is a biomimic nanosystem, coated with lipopolysaccharide-treated macrophage cell membranes with cytokine receptors enveloping gold nanocage (AuNC) as "cytokine blocker", and loaded with resolvin D1 inside into AuNC as "M2 polarization inducer" whose controlled-release could be triggered under near-infrared laser irradiation in sequence, and these chronological events were consistent with the healing process of bone tissue repair. Moreover, in vivo application of femoral bone defects revealed that the BANC composite boron-containing mesoporous bioactive glass scaffolds improved the final effects of bone tissue repair through preventing inflammatory response, promoting M2 polarization in sequence in accord with the in vitro investigation. Hence, cytokine neutralization and M2 macrophage polarization enables the BANC to enhance the bone tissue repair as a biomimetic anti-inflammation effector. Therefore, this study provides potential therapeutic strategies for trauma-mediated or inflammation-related bone defects based on a biomimetic nanomaterial with weakened pro-inflammatory and enhanced anti-inflammatory effects. STATEMENT OF SIGNIFICANCE: Cell membrane-mimic nanomaterials have been popular for blocking natural cell responses for some infection diseases, yet their role in biological process of bone repair is unknown. Here, we fabricated Biomimetic Anti-inflammatory Nano-Capsule (BANC), coated with cell membrane with cytokines receptors on the surface which could neutralize the pro-inflammatory cytokine receptor to block activated pro-inflammation, loaded with Resolvin D1 inside which could be controllably released by NIR irradiation to promote M2 macrophage polarization for the following bone formation during the process of bone repair. Administration of BANC as cytokines blocker and M2 polarization inducer to enhance the bone regeneration, thus presenting a promising potential for the treatment of bone repair and regeneration. 10.1016/j.actbio.2019.11.025
    Graphene-based nanomaterials and their potentials in advanced drug delivery and cancer therapy. Liu Jinzhao,Dong Jia,Zhang Ting,Peng Qiang Journal of controlled release : official journal of the Controlled Release Society The continuing increase of cancer morbidity and death rate requires efficient therapeutic strategies. The traditional chemotherapy usually fails to treat cancer or prolong survival rate due to its toxicity to normal cells, side effects and lack of targeting capacity. In recent years, nanomaterials have shown great potentials to treat various cancers efficiently. Graphene-based nanomaterials, especially graphene oxide (GO) and reduced GO (rGO), have arisen as promising candidates for cancer therapy. Due to their unique physicochemical and optical properties including the extremely large surface area, modifiable active groups, great biocompatibility and strong photothermal effect, they can act either as tunable carriers or active agents for advanced chemotherapeutics delivery and cancer therapy. Therefore, combing the photothermal therapy, targeted drug delivery and chemotherapy would have great potentials for efficient cancer therapy. Herein, the comprehensive understandings of the physicochemical properties and various anti-cancer applications of GO and rGO as drug delivery systems or photothermal agents are described. Also, the concerns in using GO and rGO, such as the nano-protein interaction, and possible solutions are discussed. 10.1016/j.jconrel.2018.07.034
    Grouping of carbonaceous nanomaterials based on association of patterns of inflammatory markers in BAL fluid with adverse outcomes in lungs. Yanamala Naveena,Desai Ishika C,Miller William,Kodali Vamsi K,Syamlal Girija,Roberts Jenny R,Erdely Aaron D Nanotoxicology Carbonaceous nanomaterials (CNMs) are universally being used to make commodities, as they present unique opportunities for development and innovation in the fields of engineering, biotechnology, etc. As technology advances to incorporate CNMs in industry, the potential exposures associated with these particles also increase. CNMs have been found to be associated with substantial pulmonary toxicity, including inflammation, fibrosis, and/or granuloma formation in animal models. This study attempts to categorize the toxicity profiles of various carbon allotropes, in particular, carbon black, different multi-walled carbon nanotubes, graphene-based materials, and their derivatives. Statistical and machine learning-based approaches were used to identify groups of CNMs with similar pulmonary toxicity responses from a panel of proteins measured in bronchoalveolar lavage (BAL) fluid samples and with similar pathological outcomes in the lungs. Thus, grouped particles, based on their pulmonary toxicity profiles, were used to select a small set of proteins that could potentially identify and discriminate between the toxicity profiles associated within each group. Specifically, MDC/CCL22 and MIP-3β/CCL19 were identified as common protein markers associated with both toxicologically distinct groups of CNMs. In addition, the persistent expression of other selected protein markers in BAL fluid from each group suggested their ability to predict toxicity in the lungs, i.e. fibrosis and microgranuloma formation. The advantages of such approaches can have positive implications for further research in toxicity profiling. 10.1080/17435390.2019.1640911
    Efficient two-photon luminescence for cellular imaging using biocompatible nitrogen-doped graphene quantum dots conjugated with polymers. Wu Ping-Ching,Wang Jiu-Yao,Wang Wen-Lung,Chang Chia-Yuan,Huang Chia-Hung,Yang Kun-Lin,Chang Jui-Cheng,Hsu Chih-Li Lilian,Chen Shih-Yao,Chou Ting-Mao,Kuo Wen-Shuo Nanoscale Nitrogen-doped graphene quantum dot (N-GQD) nanomaterials conjugated with polyethylenimine (PEI)-polystyrene sulfonate (PSS)-anti-epidermal growth factor receptor (Ab) antibody (N-GQD-PEI-PSS-Ab) demonstrated impressive two-photon properties and stability, signifying that they can serve as an effective two-photon contrast agent in two-photon bioimaging. Furthermore, they provided high intensity, brightness, and signal-to-noise ratios at an ultra-low two-photon excitation (TPE) power level in an observation extending to a deep, three-dimensional depth. 10.1039/c7nr06836k
    Acute Oral Administration of Single-Walled Carbon Nanotubes Increases Intestinal Permeability and Inflammatory Responses: Association with the Changes in Gut Microbiota in Mice. Chen Hanqing,Zhao Ruifang,Wang Bing,Zheng Lingna,Ouyang Hong,Wang Hailong,Zhou Xiaoyan,Zhang Dan,Chai Zhifang,Zhao Yuliang,Feng Weiyue Advanced healthcare materials With the increasing production and widespread potential applications of single-walled carbon nanotubes (SWCNTs), the possible impacts of oral administration of SWCNTs on gastrointestinal tract at currently occupational exposure limits and potential biomedical applications should be concerned. To address the concerns, mice are orally administrated of SWCNTs at doses of 0.05, 0.5, and 2.5 mg kg body weight per day for 7 d. The investigation shows that SWCNT treatment had promoted intestinal injuries at the acute dose of 2.5 mg kg per day, including increase of histological lesion scores, intestinal permeability, and proinflammatory cytokine (IL-1β, IL-6, and TNF-α) secretion. Analysis of gut microbiota composition using 16S rRNA gene sequencing approach reveals that acute oral administration of SWCNTs induces significant shifts of the predominant microbe phyla from Firmicutes to Bacteroidetes and increases abundance of proinflammatory bacteria Alitipes_uncultured_bacterium and Lachnospiraceae bacterium A4. These notable findings suggest that SWCNT-induced intestinal injury is linked to SWCNT interaction with intestinal tract and gut bacteria and the consequent triggering of "metabolic inflammation" responses. Furthermore, the study has shown that oral administration of carbon nanomaterials, including SWCNTs, multiwalled CNTs, and graphene oxide, can lead to different inflammatory responses and specific alteration in gut microbiota in mice. 10.1002/adhm.201701313
    Inherent Chemotherapeutic Anti-Cancer Effects of Low-Dimensional Nanomaterials. Fu Wen,Zhou Wenhua,Chu Paul K,Yu Xue-Feng Chemistry (Weinheim an der Bergstrasse, Germany) Low-dimensional nanomaterials (LDNs) are receiving increasing attention in cancer therapy owing to their unique properties, especially the large surface area-to-volume ratio. LDNs such as metallic nanoparticles (NPs), hydroxyapatite NPs, graphene derivatives, and black phosphorus (BP) nanosheets have been proposed for drug delivery, photothermal/photodynamic therapies, and multimodal theranostic treatments. The therapeutic effectiveness is mainly based on the physical characteristics of LDNs, but their inherent bioactivity has not been fully capitalized. In this Minireview, recent advances in the anti-cancer effects of various types of LDNs with inherent chemotherapeutic bioactivity are described and the bioactivity mechanisms are discussed on the cellular and molecular levels. BP, one of the newest and exciting members of the LDN family, is highlighted owing to the excellent inherent bioactivity, selectivity, and biocompatibility in cancer therapy. LDNs and related derivatives possess inherent bioactivity and selective chemotherapeutic effects suggesting large potential as nanostructured anti-cancer agents in cancer therapy. 10.1002/chem.201901841
    Detection and Quantification of Graphene-Family Nanomaterials in the Environment. Goodwin David G,Adeleye Adeyemi S,Sung Lipiin,Ho Kay T,Burgess Robert M,Petersen Elijah J Environmental science & technology An increase in production of commercial products containing graphene-family nanomaterials (GFNs) has led to concern over their release into the environment. The fate and potential ecotoxicological effects of GFNs in the environment are currently unclear, partially due to the limited analytical methods for GFN measurements. In this review, the unique properties of GFNs that are useful for their detection and quantification are discussed. The capacity of several classes of techniques to identify and/or quantify GFNs in different environmental matrices (water, soil, sediment, and organisms), after environmental transformations, and after release from a polymer matrix of a product is evaluated. Extraction and strategies to combine methods for more accurate discrimination of GFNs from environmental interferences as well as from other carbonaceous nanomaterials are recommended. Overall, a comprehensive review of the techniques available to detect and quantify GFNs are systematically presented to inform the state of the science, guide researchers in their selection of the best technique for the system under investigation, and enable further development of GFN metrology in environmental matrices. Two case studies are described to provide practical examples of choosing which techniques to utilize for detection or quantification of GFNs in specific scenarios. Because the available quantitative techniques are somewhat limited, more research is required to distinguish GFNs from other carbonaceous materials and improve the accuracy and detection limits of GFNs at more environmentally relevant concentrations. 10.1021/acs.est.7b04938
    Involvement of planned cell death of necroptosis in cancer treatment by nanomaterials: Recent advances and future perspectives. Sharifi Majid,Hosseinali Sara Haji,Saboury Ali Akbar,Szegezdi Eva,Falahati Mojtaba Journal of controlled release : official journal of the Controlled Release Society With the development of the field of nanomedicine, the application of nanomaterials/NPs in cancer treatment has raised questions about their potential effects as well as thier unpredictable adverse effects. To date, the cytotoxic effects of nanomaterials have been investigated based on cell survival and cellular functionality, such as membrane integrity, mitochondrial activity and cell morphology. It is increasingly noted that more detailed analysis of RCD triggered by nanomaterials is essential to understand their full mechanism of action. One the one hand, this knowledge helps us to design safe therapeutics and also increases the therapeutic potential of NP-based anti-cancer drugs. The most common pathways of RCD in cancer cells include apoptosis, necrosis, necroptosis and autophagy with the latter two often act as secondary death pathways in cancer cells when the apoptotic and necrotic pathways are non-functional. This article reviews the recent developments and future perspectives in the ability of nanomaterials/NPs to induce the above forms of RCD especially necroptosis. 10.1016/j.jconrel.2019.02.007
    Graphene-based nanomaterials for drug and/or gene delivery, bioimaging, and tissue engineering. Zhao Hong,Ding Ruihua,Zhao Xin,Li Yiwei,Qu Liangliang,Pei Hao,Yildirimer Lara,Wu Zhengwei,Zhang Weixia Drug discovery today Here, we discuss the biomedical applications of graphene-based nanomaterials (GBNs). We examine graphene and its various derivatives, including graphene, graphene oxides (GOs), reduced graphene oxides (rGOs), graphene quantum dots (GQDs), and graphene composites, and discuss their unique properties related to their biomedical applications. We also summarize the detailed biomedical applications of GBNs, including drug and/or gene delivery, bioimaging, and tissue engineering. We also highlight the toxicity of these nanomaterials. 10.1016/j.drudis.2017.04.002
    A Review on Graphene-Based Nanomaterials in Biomedical Applications and Risks in Environment and Health. Dasari Shareena Thabitha P,McShan Danielle,Dasmahapatra Asok K,Tchounwou Paul B Nano-micro letters Graphene-based nanomaterials (GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, disease diagnosis and therapy. Although a large amount of researches have been conducted on these novel nanomaterials, limited comprehensive reviews are published on their biomedical applications and potential environmental and human health effects. The present research aimed at addressing this knowledge gap by examining and discussing: (1) the history, synthesis, structural properties and recent developments of GBNs for biomedical applications; (2) GBNs uses as therapeutics, drug/gene delivery and antibacterial materials; (3) GBNs applications in tissue engineering and in research as biosensors and bioimaging materials; and (4) GBNs potential environmental effects and human health risks. It also discussed the perspectives and challenges associated with the biomedical applications of GBNs. 10.1007/s40820-018-0206-4
    Photodynamic Therapy Based on Graphene and MXene in Cancer Theranostics. Gazzi Arianna,Fusco Laura,Khan Anooshay,Bedognetti Davide,Zavan Barbara,Vitale Flavia,Yilmazer Acelya,Delogu Lucia Gemma Frontiers in bioengineering and biotechnology Cancer is one of the leading causes of death in the world. Therefore, the development of new advanced and targeted strategies in cancer research for early diagnosis and treatment has become essential to improve diagnosis outcomes and reduce therapy side effects. Graphene and more recently, MXene, are the main representatives of the family of two-dimensional (2D) materials and are widely studied as multimodal nanoplatforms for cancer diagnostics and treatment, in particular leveraging their potentialities as photodynamic therapeutic agents. Indeed, due to their irreplaceable physicochemical properties, they are virtuous allies for photodynamic therapy (PDT) in combination with bioimaging, photothermal therapy, as well as drug and gene delivery. In this review, the rapidly progressing literature related to the use of these promising 2D materials for cancer theranostics is described in detail, highlighting all their possible future advances in PDT. 10.3389/fbioe.2019.00295
    Controlling enzyme function through immobilisation on graphene, graphene derivatives and other two dimensional nanomaterials. Ramakrishna Tejaswini R B,Nalder Tim D,Yang Wenrong,Marshall Susan N,Barrow Colin J Journal of materials chemistry. B Robust enzyme immobilisation methods that preserve enzyme activity while enabling enzymes to be recovered and reused multiple times have important applications in biocatalysis. However, immobilisation can change the functionality of enzymes, both in terms of their level of activity and their selectivity. These changes in activity are unpredictable and at present cannot be controlled, but if fully understood at a fundamental level could offer the opportunity to create highly targetted enzyme systems for specific applications. In this review, we will highlight the use of two dimensional nanomaterials (2D NMs), particularly graphene and its derivatives, as immobilisation materials to modify and control the selectivity and activity of various enzymes. The fundamental information obtained from immobilising enzymes on 2D NMs allows for the implementation of improved immobilisation strategies and assists in the design of next generation nano- and macro-materials for enzyme immobilisation. We hope that this review will highlight the potential for tailoring enzyme activity and selectivity through immobilisation. 10.1039/c8tb00313k
    Targeting non-apoptotic cell death in cancer treatment by nanomaterials: Recent advances and future outlook. Sepand Mohammad Reza,Ranjbar Sheyda,Kempson Ivan M,Akbariani Mostafa,Muganda Willis Collins Akeyo,Müller Mareike,Ghahremani Mohammad Hossein,Raoufi Mohammad Nanomedicine : nanotechnology, biology, and medicine Many tumors develop resistance to most of the apoptosis-based cancer therapies. In this sense targeting non-apoptotic forms of cell death including necroptosis, autophagy and ferroptosis may have therapeutic benefits in apoptosis-defective cancer cells. Nanomaterials have shown great advantages in cancer treatment owing to their unique characteristics. Besides, the capability of nanomaterials to induce different forms of cell death has gained widespread attention in cancer treatment. Reports in this field reflect the therapeutic potential of necroptotic cell death induced by nanomaterials in cancer. Also, autophagic cell death induced by nanomaterials alone and as a part of chemo-, radio- and photothermal therapy holds great promise as anticancer therapeutic option. Besides, ferroptosis induction by iron-based nanomaterials in drug delivery, immunotherapy, hyperthermia and imaging systems shows promising results in malignancies. Hence, this review is devoted to the latest efforts and the challenges in this field of research and its clinical merits. 10.1016/j.nano.2020.102243
    Biodegradation of graphene-based nanomaterials in blood plasma affects their biocompatibility, drug delivery, targeted organs and antitumor ability. Li Dandan,Hu Xiangang,Zhang Suyan Biomaterials The extensive use of graphene-family nanomaterials (GFNs) in biomedicine and other fields has intentionally or unintentionally resulted in their introduction into the blood circulation system, but the effects of the biotransformation of GFNs in blood plasma on their biocompatibility, organ targeting, drug delivery and antitumor ability remain unclear. The present work discovered that GFN sheets were degraded in human blood plasma to holey sheets and aromatic hydrocarbons. The carbon atoms connected with oxygen-containing groups in the planes of GFNs were the initial attack sites for active substances (e.g., OH and O) in blood plasma. Subsequently, CC/CC bonds were broken. The reaction rate depended strongly on the extent of oxidization of GFNs. The pristine GFNs caused secondary structure damage to proteins and disturbances of cellular metabolic pathways. In contrast, the biotransformed nanomaterials presented high biocompatibility and were located in and targeted different tissues from their pristine forms, which influenced specific organ targeting therapy. The biotransformed nanomaterials also exhibited higher efficiencies of drug delivery (drug release and location) and killing tumor cells in vitro and in vivo. These findings provide insights into the application of nanomaterials in human healthcare using biotransformed nanomaterials. 10.1016/j.biomaterials.2019.02.020
    Adsorptive removal of heavy metal ions using graphene-based nanomaterials: Toxicity, roles of functional groups and mechanisms. Ahmad Siti Zu Nurain,Wan Salleh Wan Norharyati,Ismail Ahmad Fauzi,Yusof Norhaniza,Mohd Yusop Mohd Zamri,Aziz Farhana Chemosphere The endless introduction of toxic heavy metals through industrialization has worsened the heavy metal pollution in the environment. Thus, the need for its effective removal has become more crucial than before. Studies on graphene-based nanomaterials and their use in removing heavy metals are gaining tremendous traction over the past decade. The properties of graphene oxide (GO), such as large surface areas, desired functional groups and excellent mechanical properties are advantageous. Nevertheless, due to its tendency to agglomerate and difficulty in phase separation after treatment, the functionalization of GO using various materials of different surface functional groups is an ongoing study. The surface modification of GO is done by using various materials to introduce heteroatoms, which have high affinity for heavy metals. This review summarizes the utilization of different surface functional groups, such as oxygen-containing, nitrogen-containing, and sulphur-containing functionalized graphene oxide composites in the adsorption of cationic and oxyanionic heavy metals. The toxicity of these heavy metals is also addressed. Furthermore, the interactions between adsorbents and heavy metals which are influenced by pH and surface functional groups, are also discussed in detail. This is followed by the review in adsorption isotherms and kinetics. Future research needs are also offered. 10.1016/j.chemosphere.2020.126008
    Electroactive Scaffolds for Neurogenesis and Myogenesis: Graphene-Based Nanomaterials. Zhang Zhongyang,Klausen Lasse Hyldgaard,Chen Menglin,Dong Mingdong Small (Weinheim an der Bergstrasse, Germany) One of the major issues in tissue engineering is constructing a functional scaffold to support cell growth and also provide proper synergistic guidance cues. Graphene-based nanomaterials have emerged as biocompatible and electroactive scaffolds for neurogenesis and myogenesis, due to their excellent tunable chemical, physical, and mechanical properties. This review first assesses the recent investigations focusing on the fabrication and applications of graphene-based nanomaterials for neurogenesis and myogenesis, in the form of either 2D films, 3D scaffolds, or composite architectures. Besides, because of their outstanding electrical properties, graphene family materials are particularly suitable for designing electroactive scaffolds that could provide proper electrical stimulation (i.e., electrical or photo stimuli) to promote the regeneration of excitable neurons and muscle cells. Therefore, the effects and mechanism of electrical and/or photo stimulations on neurogenesis and myogenesis are followed. Furthermore, studies on their biocompatibilities and toxicities especially to neural and muscle cells are evaluated. Finally, the future challenges and perspectives in facilitating the development of clinical translation of graphene-family nanomaterials in treating neurodegenerative and muscle diseases are discussed. 10.1002/smll.201801983
    Recent advances in graphene-based nanomaterials: properties, toxicity and applications in chemistry, biology and medicine. Yao Jun,Wang Heng,Chen Min,Yang Mei Mikrochimica acta This review (with 239 refs.) summarizes the progress that has been made in applications of graphene-based nanomaterials (such as plain graphene, graphene oxides, doped graphene oxides, graphene quantums dots) in biosensing, imaging, drug delivery and diagnosis. Following an introduction into the field, a first large section covers the toxicity of graphene and its derivatives (with subsections on bacterial toxicity and tissue toxicity). The use of graphene-based nanomaterials in sensors is reviewed next, with subsections on electrochemical, FET-based, fluorescent, chemiluminescent and colorimetric sensors and probes. The large field of imaging is treated next, with subchapters on optical, PET-based, and magnetic resonance based methods. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends. Graphical Abstract Schematic presentation of the potential applications of graphene-based materials in life science and biomedicine, emphatically reflected in some vital areas such as DNA analysis, biological monitoring, drug delivery, in vitro labelling, in vivo imaging, tumor target, etc. 10.1007/s00604-019-3458-x
    Two-dimensional nanomaterials beyond graphene for antibacterial applications: current progress and future perspectives. Mei Linqiang,Zhu Shuang,Yin Wenyan,Chen Chunying,Nie Guangjun,Gu Zhanjun,Zhao Yuliang Theranostics The marked augment of drug-resistance to traditional antibiotics underlines the crying need for novel replaceable antibacterials. Research advances have revealed the considerable sterilization potential of two-dimension graphene-based nanomaterials. Subsequently, two-dimensional nanomaterials beyond graphene (2D NBG) as novel antibacterials have also demonstrated their power for disinfection due to their unique physicochemical properties and good biocompatibility. Therefore, the exploration of antibacterial mechanisms of 2D NBG is vital to manipulate antibacterials for future applications. Herein, we summarize the recent research progress of 2D NBG-based antibacterial agents, starting with a detailed introduction of the relevant antibacterial mechanisms, including direct contact destruction, oxidative stress, photo-induced antibacterial, control drug/metallic ions releasing, and the multi-mode synergistic antibacterial. Then, the effect of the physicochemical properties of 2D NBG on their antibacterial activities is also discussed. Additionally, a summary of the different kinds of 2D NBG is given, such as transition-metal dichalcogenides/oxides, metal-based compounds, nitride-based nanomaterials, black phosphorus, transition metal carbides, and nitrides. Finally, we rationally analyze the current challenges and new perspectives for future study of more effective antibacterial agents. This review not only can help researchers grasp the current status of 2D NBG antibacterials, but also may catalyze breakthroughs in this fast-growing field. 10.7150/thno.39701
    Graphene-Based Nanomaterials Toxicity in Fish. Dasmahapatra Asok K,Dasari Thabitha P S,Tchounwou Paul B Reviews of environmental contamination and toxicology Due to their unique physicochemical properties, graphene-based nanoparticles (GPNs) constitute one of the most promising types of nanomaterials used in biomedical research. GPNs have been used as polymeric conduits for nerve regeneration and carriers for targeted drug delivery and in the treatment of cancer via photothermal therapy. Moreover, they have been used as tracers to study the distribution of bioactive compounds used in healthcare. Due to their extensive use, GPN released into the environment would probably pose a threat to living organisms and ultimately to human health. Their accumulation in the aquatic environment creates problems to aquatic habitats as well as to food chains. Until now the potential toxic effects of GPN are not properly understood. Despite agglomeration and long persistence in the environment, GPNs are able to cross the cellular barriers successfully, entered into the cells, and are able to interact with almost all the cellular sites including the plasma membrane, cytoplasmic organelles, and nucleus. Their interaction with DNA creates more potential threats to both the genome and epigenome. In this brief review, we focused on fish, mainly zebrafish (Danio rerio), as a potential target animal of GPN toxicity in the aquatic ecosystem. 10.1007/398_2018_15