Repair of dural defects with electrospun bacterial cellulose membranes in a rabbit experimental model.
Jing Yao,Ma Xia,Xu Chen,Tian Heng-Li,Chen Shi-Wen
Materials science & engineering. C, Materials for biological applications
To evaluate the advantages and mechanisms involved in repairing rabbit dural defect with a novel electrospun bacterial cellulose (EBC) membrane, a series of experiments were carried out in vitro and in vivo. Compared with common bacterial cellulose (BC) membrane, a more dispersed and regular fiber structure and a better porosity and water holding capacity were found in the EBC membrane, which also had superior degradability. However, the biomechanical properties were slightly decreased. The results demonstrated that BC and EBC membranes had little effect on proliferation and apoptosis of mouse fibroblast cells. There were no complications such as infection, cerebrospinal fluid leakage, epilepsy and brain swelling after BC and EBC membrane repairs in rabbit models. Using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot, the early inflammatory reactions in the EBC group were shown to be lower than in the BC group, and were close to the autologous dura mater group. Histological observations and western blot revealed more collagen fibers evenly distributed on the outer side of EBC membranes than in the BC and unpatched groups, and fewer brain tissue adhesions and epidural scars were found in the EBC group. Compared with common BC membrane, the EBC membrane had better biophysical properties and biocompatibility. It is expected to be a suitable alternative material for the repair of damaged dura mater.
The Nanofication and Functionalization of Bacterial Cellulose and Its Applications.
Choi Soon Mo,Shin Eun Joo
Nanomaterials (Basel, Switzerland)
Since economic and environmental issues have become critical in the last several years, the amount of sustainable bio-based production has increased. In this article, microbial polysaccharides, including bacterial cellulose (BC), are analyzed as promising resources with the potential for applications in biofields and non-biofields. Many scientists have established various methods of BC production, nanofication, and functionalization. In particular, this review will address the essential advances in recent years focusing on nanofication methods and nanoficated BC applications as well as functionalization methods and functionalized BC applications.
Chemical Modification of Bacterial Cellulose for the Development of an Antibacterial Wound Dressing.
Orlando Isabel,Basnett Pooja,Nigmatullin Rinat,Wang Wenxin,Knowles Jonathan C,Roy Ipsita
Frontiers in bioengineering and biotechnology
Bacterial cellulose is a bacterially derived polymer with great potential for application in wound healing due to its innate properties such as high biocompatibility and biodegradability. In addition to this, it is naturally biosynthesized by bacteria as a hydrogel, which makes it an optimal substrate for the treatment of dry wounds, where additional moisture is required to facilitate the healing process. However, this polymer lacks antibacterial properties. As bacterial infections are becoming increasingly common and difficult to treat due to antimicrobial resistance, it is of crucial importance to develop strategies for the modification of cellulose to ensure protection against bacterial contamination. In this study, a green-chemistry approach was proposed for the functionalization of cellulose to introduce antibacterial functional groups. Two different active agents, namely glycidyl trimethylammonium chloride and glycidyl hexadecyl ether, were used for the covalent derivatization of the hydroxyl groups of glucose through a heterogeneous reaction in basic aqueous conditions. The modified material was chemically and mechanically characterized by solid-state techniques and rheological measurements. A biological assessment was then carried out both using bacterial cells and human keratinocytes. It was observed that the functionalization performed induced a reduction of approximately half of the bacterial population within 24 h of direct contact with subsp. aureus Rosenbach 6538P and (Migula) Castellani and Chalmers ATCC 8739 (respectively, a reduction of 53% and 43% in the cell number was registered for the two strains). In parallel, cytotoxicity studies performed on keratinocytes (HaCaT cell line) showed cell viability in the range of 90 to 100% for up to 6 days of direct contact with both unmodified and modified samples. The morphology of the cells was also visually evaluated, and no significant difference was noted as compared to the control. Finally, the scratch assay evidenced good wound closure rates in the presence of the samples, with complete coverage of the scratched area after 5 days for both the modified cellulose and the positive control (i.e., keratinocytes growth medium). Overall, the modified hydrogel showed promising features, confirming its potential as an alternative substrate to develop a sustainable, antibacterial and biocompatible wound dressing.
Modified Bacterial Cellulose Dressings to Treat Inflammatory Wounds.
Beekmann Uwe,Zahel Paul,Karl Berit,Schmölz Lisa,Börner Friedemann,Gerstmeier Jana,Werz Oliver,Lorkowski Stefan,Wiegand Cornelia,Fischer Dagmar,Kralisch Dana
Nanomaterials (Basel, Switzerland)
Natural products suited for prophylaxis and therapy of inflammatory diseases have gained increasing importance. These compounds could be beneficially integrated into bacterial cellulose (BC), which is a natural hydropolymer applicable as a wound dressing and drug delivery system alike. This study presents experimental outcomes for a natural anti-inflammatory product concept of boswellic acids from frankincense formulated in BC. Using esterification respectively (resp.) oxidation and subsequent coupling with phenylalanine and tryptophan, -modification of BC was tested to facilitate lipophilic active pharmaceutical ingredient (API) incorporation. Diclofenac sodium and indomethacin were used as anti-inflammatory model drugs before the findings were transferred to boswellic acids. By acetylation of BC fibers, the loading efficiency for the more lipophilic API indomethacin and the release was increased by up to 65.6% and 25%, respectively, while no significant differences in loading could be found for the API diclofenac sodium. -modifications could be made while preserving biocompatibility, essential wound dressing properties and anti-inflammatory efficacy. Eventually, in vitro wound closure experiments and evaluations of the effect of secondary dressings completed the study.
Evaluation of Different Methods for Cultivating for Bacterial Cellulose and Montmorillonite Biocomposite Production: Wound-Dressing Applications.
Hodel Katharine Valéria Saraiva,Fonseca Larissa Moraes Dos Santos,Santos Isa Moreira da Silva,Cerqueira Jamile Costa,Santos-Júnior Raimundo Evangelista Dos,Nunes Silmar Baptista,Barbosa Josiane Dantas Viana,Machado Bruna Aparecida Souza
Bacterial cellulose (BC) has received considerable attention due to its unique properties, including an ultrafine network structure with high purity, mechanical strength, inherent biodegradability, biocompatibility, high water-holding capacity and high crystallinity. These properties allow BC to be used in biomedical and industrial applications, such as medical product. This research investigated the production of BC by ATCC 23769 using different carbon sources (glucose, mannitol, sucrose and xylose) at two different concentrations (25 and 50 g∙L). The BC produced was used to develop a biocomposite with montmorillonite (MMT), a clay mineral that possesses interesting characteristics for enhancing BC physical-chemical properties, at 0.5, 1, 2 and 3% concentrations. The resulting biocomposites were characterized in terms of their physical and barrier properties, morphologies, water-uptake capacities, and thermal stabilities. Our results show that bacteria presented higher BC yields in media with higher glucose concentrations (50 g∙L) after a 14-day incubation period. Additionally, the incorporation of MMT significantly improved the mechanical and thermal properties of the BC membranes. The degradation temperature of the composites was extended, and a decrease in the water holding capacity (WHC) and an improvement in the water release rate (WRR) were noted. Determining a cost-effective medium for the production of BC and the characterization of the produced composites are extremely important for the biomedical applications of BC, such as in wound dressing materials.
Characterization of Bacterial Cellulose-Based Wound Dressing in Different Order Impregnation of Chitosan and Collagen.
Pasaribu Khatarina Meldawati,Gea Saharman,Ilyas Syafruddin,Tamrin Tamrin,Radecka Izabela
Bacterial cellulose (BC), chitosan (Chi), and collagen (Col) are known as biopolymers which have met some properties that are required as wound dressing. This study focused on investigating the fabrication of BC-based wound dressing with chitosan and collagen, since chitosan has red blood cells binding and anti-bacterial properties, while collagen can support cell and tissue growth for skin wounds. The BC-based wound dressing was prepared by impregnating BC fibers in the chitosan and/or collagen solution for 24 h. FTIR was used to confirm the intermolecular interaction of amine and hydroxyl group of chitosan and/or collagen in BC-based wound dressing. Furthermore, the XRD diffractogram of the wound dressing show broader peaks at 14.2°, 16.6°, and 22.4° due to the presence of chitosan and collagen molecules in BC fibers. These results were then supported by SEM images which confirmed that chitosan and collagen were well penetrated into BC fibers. TGA curves revealed that BC/Chi/Col has better thermal properties based on the T compare to BC/Col/Chi. Feasibility of the mats to be applied as wound dressing was also supported by other tests, i.e., water content, porosity, and hemocompatibility, which indicates that the wound dressing is classified as nonhemolytic materials. However, BC/Col/Chi was considered a more potential wound dressing to be applied compared to BC/Chi/Col since it has larger pores and showed better antibacterial properties (larger zones of inhibition) against and via disk diffusion tests.
Latest Advances on Bacterial Cellulose-Based Antibacterial Materials as Wound Dressings.
Zheng Lu,Li Shanshan,Luo Jiwen,Wang Xiaoying
Frontiers in bioengineering and biotechnology
At present, there are various wound dressings that can protect the wound from further injury or isolate the external environment in wound treatment. Whereas, infection and slow self-healing still exist in wound healing process. Therefore, it is urgent to develop an ideal wound dressing with good biocompatibility and strong antibacterial activity to promote wound healing. Bacterial cellulose is a kind of promising biopolymer because it can control wound exudate and provide a moist environment for wound healing. However, the lack of antibacterial activity limits its application. In this paper, the advantages of bacterial cellulose as wound dressings were introduced, and the preparation and research progress of bacterial cellulose-based antibacterial composites in recent years were reviewed, including adding antibiotics, combining with inorganic antibacterial agents or organic antibacterial agents. Finally, the existing problems and future development direction of bacterial cellulose-based antibacterial wound dressings were discussed.
Large-scale tight-binding simulations of quantum transport in ballistic graphene.
Calogero Gaetano,Papior Nick R,Bøggild Peter,Brandbyge Mads
Journal of physics. Condensed matter : an Institute of Physics journal
Graphene has proven to host outstanding mesoscopic effects involving massless Dirac quasiparticles travelling ballistically resulting in the current flow exhibiting light-like behaviour. A new branch of 2D electronics inspired by the standard principles of optics is rapidly evolving, calling for a deeper understanding of transport in large-scale devices at a quantum level. Here we perform large-scale quantum transport calculations based on a tight-binding model of graphene and the non-equilibrium Green's function method and include the effects of p-n junctions of different shape, magnetic field, and absorptive regions acting as drains for current. We stress the importance of choosing absorbing boundary conditions in the calculations to correctly capture how current flows in the limit of infinite devices. As a specific application we present a fully quantum-mechanical framework for the '2D Dirac fermion microscope' recently proposed by Bøggild et al (2017 Nat. Commun. 8 10.1038), tackling several key electron-optical effects therein predicted via semiclassical trajectory simulations, such as electron beam collimation, deflection and scattering off Veselago dots. Our results confirm that a semiclassical approach to a large extend is sufficient to capture the main transport features in the mesoscopic limit and the optical regime, but also that a richer electron-optical landscape is to be expected when coherence or other purely quantum effects are accounted for in the simulations.
Bacterial cellulose and hyaluronic acid hybrid membranes: Production and characterization.
Lopes Tatyane Duran,Riegel-Vidotti Izabel Cristina,Grein Aline,Tischer Cesar Augusto,Faria-Tischer Paula Cristina de Sousa
International journal of biological macromolecules
In this study, the effect of the addition of hyaluronic acid (HA) on bacterial cellulose (BC) production, under static conditions was evaluated in terms of the properties of the resulting BC hybrid membranes. HA was added to the fermentation process in three distinct time points: first day (BC-T0), third day (BC-T3) and sixth day (BC-T6). Analyses of FT-IR and CP/MAS (13)C NMR confirmed the presence of HA in bacterial cellulose membranes. The crystal structure, crystallinity index (Ic) surface roughness, thermal stability and hybrophobic/hydrophilic character changed. Membranes with higher roughness were produced with HA added on the first and third day of fermentation process. The surface energy of BC/HA membranes was calculated and more hydrophilic membranes were produced by the addition of HA on the third and sixth day, also resulting in more thermally stable materials. The results demonstrate that bacterial cellulose/hyaluronic acid hybrid membranes can be produced in situ and suggest that HA interacts with the sub-elementary bacterial cellulose fibrils, changing the properties of the membranes. The study and understanding of the factors that affect those properties are of utmost importance for the safe and efficient use of BC as biomaterials in numerous applications, specifically in the biological field.
Advances in biomedical and pharmaceutical applications of functional bacterial cellulose-based nanocomposites.
Ullah Hanif,Wahid Fazli,Santos Hélder A,Khan Taous
Bacterial cellulose (BC) synthesized by certain species of bacteria, is a fascinating biopolymer with unique physical and mechanical properties. BC's applications range from traditional dessert, gelling, stabilizing and thickening agent in the food industry to advanced high-tech applications, such as immobilization of enzymes, bacteria and fungi, tissue engineering, heart valve prosthesis, artificial blood vessels, bone, cartilage, cornea and skin, and dental root treatment. Various BC-composites have been designed and investigated in order to enhance its biological applicability. This review focuses on the application of BC-based composites for microbial control, wound dressing, cardiovascular, ophthalmic, skeletal, and endodontics systems. Moreover, applications in controlled drug delivery, biosensors/bioanalysis, immobilization of enzymes and cells, stem cell therapy and skin tissue repair are also highlighted. This review will provide new insights for academia and industry to further assess the BC-based composites in terms of practical applications and future commercialization for biomedical and pharmaceutical purposes.
Bacterial cellulose-based materials and medical devices: current state and perspectives.
Petersen Nathan,Gatenholm Paul
Applied microbiology and biotechnology
Bacterial cellulose (BC) is a unique and promising material for use as implants and scaffolds in tissue engineering. It is composed of a pure cellulose nanofiber mesh spun by bacteria. It is remarkable for its strength and its ability to be engineered structurally and chemically at nano-, micro-, and macroscales. Its high water content and purity make the material biocompatible for multiple medical applications. Its biocompatibility, mechanical strength, chemical and morphologic controllability make it a natural choice for use in the body in biomedical devices with broader application than has yet been utilized. This paper reviews the current state of understanding of bacterial cellulose, known methods for controlling its physical and chemical structure (e.g., porosity, fiber alignment, etc.), biomedical applications for which it is currently being used, or investigated for use, challenges yet to be overcome, and future possibilities for BC.
Antimicrobial functionalization of bacterial nanocellulose by loading with polihexanide and povidone-iodine.
Wiegand Cornelia,Moritz Sebastian,Hessler Nadine,Kralisch Dana,Wesarg Falko,Müller Frank A,Fischer Dagmar,Hipler Uta-Christina
Journal of materials science. Materials in medicine
Bacterial nanocellulose (BNC) is chemically identical with plant cellulose but free of byproducts like lignin, pectin, and hemicelluloses, featuring a unique reticulate network of fine fibers. BNC sheets are mostly obtained by static cultivation. Now, a Horizontal Lift Reactor may provide a cost efficient method for mass production. This is of particular interest as BNC features several properties of an ideal wound dressing although it exhibits no bactericidal activity. Therefore, BNC was functionalized with the antiseptics povidone-iodine (PI) and polihexanide (PHMB). Drug loading and release, mechanical characteristics, biocompatibility, and antimicrobial efficacy were investigated. Antiseptics release was based on diffusion and swelling according to Ritger-Peppas equation. PI-loaded BNC demonstrated a delayed release compared to PHMB due to a high molar drug mass and structural changes induced by PI insertion into BNC that also increased the compressive strength of BNC samples. Biological assays demonstrated high biocompatibility of PI-loaded BNC in human keratinocytes but a distinctly lower antimicrobial activity against Staphylococcus aureus compared to PHMB-loaded BNC. Overall, BNC loaded with PHMB demonstrated a better therapeutic window. Moreover, compressive and tensile strength were not changed by incorporation of PHMB into BNC, and solidity during loading and release could be confirmed.
Latest Advances on Bacterial Cellulose-Based Materials for Wound Healing, Delivery Systems, and Tissue Engineering.
Carvalho Tiago,Guedes Gabriela,Sousa Filipa L,Freire Carmen S R,Santos Hélder A
Bacterial cellulose (BC) is a nanocellulose form produced by some nonpathogenic bacteria. BC presents unique physical, chemical, and biological properties that make it a very versatile material and has found application in several fields, namely in food industry, cosmetics, and biomedicine. This review overviews the latest state-of-the-art usage of BC on three important areas of the biomedical field, namely delivery systems, wound dressing and healing materials, and tissue engineering for regenerative medicine. BC will be reviewed as a promising biopolymer for the design and development of innovative materials for the mentioned applications. Overall, BC is shown to be an effective and versatile carrier for delivery systems, a safe and multicustomizable patch or graft for wound dressing and healing applications, and a material that can be further tuned to better adjust for each tissue engineering application, by using different methods.
Bacterial Cellulose: Functional Modification and Wound Healing Applications.
He Wei,Wu Jian,Xu Jin,Mosselhy Dina A,Zheng Yudong,Yang Siming
Advances in wound care
Wound dressings are frequently used for wound covering and healing. Ideal wound dressings should provide a moist environment for wounds and actively promote wound healing and skin recovery. The materials used as ideal wound dressings should possess specific properties, thus accelerating skin tissue regeneration process. Bacterial cellulose (BC) is a natural polymer synthesized by some bacteria. As a kind of natural biopolymer, BC shows good biological activity, biodegradability, and biological adaptability. It has many unique physical, chemical, and biological properties, such as ultrafine nanofiber network, high crystallinity, high water absorption and retention capacity, and high tensile strength and elastic modulus. These excellent properties of BC have laid the foundation for its application as dressing in wound healing. To optimize the biocompatibility and antimicrobial activity of BC, different methods including microbial fermentation, physical modification, chemical modification, and compound modification have been adopted to modify BC to ensure a better application in wound healing. BC-based wound dressings have been applied in infected wounds, acute traumatic injuries, burns, and diabetic wounds, showing remarkable therapeutic effects on promoting wound healing. Furthermore, there have been some commercial BC-based dressings and they have been utilized in clinical practice. Because of its excellent physicochemical characteristics and biological properties, BC shows high clinical value to be used as a wound dressing for skin tissue regeneration.
Epidermal and fibroblast growth factors incorporated polyvinyl alcohol electrospun nanofibers as biological dressing scaffold.
Asiri Amnah,Saidin Syafiqah,Sani Mohd Helmi,Al-Ashwal Rania Hussien
In this study, single, mix, multilayer Polyvinyl alcohol (PVA) electrospun nanofibers with epidermal growth factor (EGF) and fibroblast growth factor (FGF) were fabricated and characterized as a biological wound dressing scaffolds. The biological activities of the synthesized scaffolds have been verified by in vitro and in vivo studies. The chemical composition finding showed that the identified functional units within the produced nanofibers (O-H and N-H bonds) are attributed to both growth factors (GFs) in the PVA nanofiber membranes. Electrospun nanofibers' morphological features showed long protrusion and smooth morphology without beads and sprayed with an average range of 198-286 nm fiber diameter. The fiber diameters decrement and the improvement in wettability and surface roughness were recorded after GFs incorporated within the PVA Nanofibers, which indicated potential good adoption as biological dressing scaffolds due to the identified mechanical properties (Young's modulus) in between 18 and 20 MPa. The MTT assay indicated that the growth factor release from the PVA nanofibers has stimulated cell proliferation and promoted cell viability. In the cell attachment study, the GFs incorporated PVA nanofibers stimulated cell proliferation and adhered better than the PVA control sample and presented no cytotoxic effect. The in vivo studies showed that compared to the control and single PVA-GFs nanofiber, the mix and multilayer scaffolds gave a much more wound reduction at day 7 with better wound repair at day 14-21, which indicated to enhancing tissue regeneration, thus, could be a projected as a suitable burn wound dressing scaffold.
[Impact of interleukin-10 and interleukin-28 gene polymorphisms on the development and course of lupus nephritis].
Krasnova T N,Samokhodskaya L M,Ivanitsky L V,Korogodina A D,Borisov E N,Nikiforova N V,Novikov P I,Kamalov A A,Mukhin N A
AIM:To assess the relationship of the carriage of IL-10-1080 G/A and IL-28 rs8099917 C/T polymorphisms to the course of lupus nephritis (LN). SUBJECTS AND METHODS:Ninety-nine patients with systemic lupus erythematosus (SLE), including 68 with LN, were examined. Gene polymorphisms were analyzed using standard molecular genetic techniques. The frequency of the clinical manifestations of LN was analyzed; renal survival (RS) was estimated by the Kaplan-Meier method. RESULTS:Ten-year RS rates were 80 and 86% of the patients with and without the mutant IL-10 allele, respectively (p = 0.78). The 10-year RS was lower (75%) in carriers of the mutant IL-28 rsl2979860 allele than in patients without this mutant allele (83%; p = 0.049) and in those of the mutant IL28 rs8099917 allele than in patients without the above mutant allele (67 and 88%, respectively; p = 0.047). LN patients, carriers of the mutant IL-10-1028 G/A allele, were observed to have higher-grade proteinuria in the presence of nephritic syndrome (mean 6.1 g/l) than those without the mutant allele of this gene (mean 2.9 g/l; p = 0.034). However, the mutant allele carriers responded to treatment better (p = 0.050). The mutant IL-10 and IL-28 alleles were unassociated with the development of rapidly progressive nephritis, the activity of a renal lupus process, and the rate of onset of SLE and LN. CONCLUSION:In the LN patients, the carriage of the mutant IL-10 allele A is associated with a better response to treatment and that of the mutant IL-28 allele is linked to the severe course of the disease.
Recent developments in the production and applications of bacterial cellulose fibers and nanocrystals.
Reiniati Isabela,Hrymak Andrew N,Margaritis Argyrios
Critical reviews in biotechnology
Cellulosic nanomaterials provide a novel and sustainable platform for the production of high performance materials enabled by nanotechnology. Bacterial cellulose (BC) is a highly crystalline material and contains pure cellulose without lignin and hemicellulose. BC offers an opportunity to provide control of the products' properties in-situ, via specific BC production methods and culture conditions. The BC potential in advanced material applications are hindered by a limited knowledge of optimal BC production conditions, efficient process scale-up, separation methods, and purification methods. There is a growing body of work on the production of bacterial cellulose nanocrystals (BCNs) from BC fibers. However, there is limited information regarding the effect of BC fibers' characteristics on the production of nanocrystals. This review describes developments in BC and BCNs production methods and factors affecting their yield and physical characteristics.
Fabrication of bacterial cellulose-collagen composite scaffolds and their osteogenic effect on human mesenchymal stem cells.
Noh Yong Kwan,Dos Santos Da Costa Avelino,Park Yong Seek,Du Ping,Kim Ik-Hwan,Park Kwideok
Scaffold plays a critical role in stem cell differentiation and tissue regeneration. Composite scaffolds composed of bacterial cellulose (BC) and collagen (Col) in different ratios (1:1, 3:1, 5:1) were fabricated in this study. The composite scaffolds exhibit a well-organized interconnected porous structure, significantly better physical stability than Col scaffold, and more water uptake up to 400%. They were also favorable with cell attachment and growth. After osteogenic induction of umbilical cord blood derived mesenchymal stem cells (UCB-MSCs) for 3 weeks, we found more up-regulated osteogenic markers (collagen type 1, osteocalcin, bone sialoprotein) and significantly elevated proteins and calcium deposition, particularly with BC/Col (5:1) scaffold. When PKH-26 pre-labelled MSC-loaded scaffolds were subcutaneously transplanted in a mouse model, they showed many PKH-26-labelled cells and positive signals of α-smooth muscle actin, for neovascularization in the BC/Col (5:1). The current work demonstrates that our BC/Col composites may be promising as a bone tissue-engineered scaffold.
Fabrication of bacterial cellulose-based wound dressings with improved performance by impregnation with alginate.
Sulaeva Irina,Hettegger Hubert,Bergen Anna,Rohrer Christian,Kostic Mirjana,Konnerth Johannes,Rosenau Thomas,Potthast Antje
Materials science & engineering. C, Materials for biological applications
Bacterial cellulose (BC) hydrogels are among the most efficient materials already being used for the treatment of complex wounds. The moist environment provided by the BC dressing is a key feature assuring efficient wound recovery. Improving the dressings´ moisture-holding ability facilitates its application and leads to an economically preferable extended wear time. To produce materials with reduced moisture loss, BC dressings were impregnated with a secondary hydrophilic component: alginate. The feasibility of an industrial fabrication of this composite was evaluated on pilot scale equipment. It was shown that the procedure can easily be scaled up without significantly increasing the manufacturing time. The resultant composite possessed improved water-retention properties, providing a smooth dressing exchange as demonstrated by a wound-imitating model. The new materials were moreover shown to be compatible with an antimicrobially active compound, which assures their efficiency in the treatment of highly colonized wounds.
Bacterial cellulose micro-nano fibres for wound healing applications.
Ahmed Jubair,Gultekinoglu Merve,Edirisinghe Mohan
Bacterial cellulose (BC) is cellulose produced by a few limited species of bacteria in given conditions. BC has many remarkable properties such as its attractive mechanical properties, water uptake ability and biocompatibility which makes it a very desirable material to be used for wound healing. Inherently due to these important properties, the material is very resistant to easy processing and thus difficult to produce into useful entities. Additionally, being rate limited by the dependency on bacterial production, high yield is difficult to obtain and thus secondary material processing is sought after. In this review, BC is explained in terms of synthesis, structure and properties. These beneficial properties are directly related to the material's great potential in wound healing where it has also been trialled commercially but ultimately failed due to processing issues. However, more recently there has been increased frequency in scientific work relating to BC processing into hybrid polymeric fibres using common laboratory fibre forming techniques such as electrospinning and pressurised gyration. This paper summarises current progress in BC fibre manufacturing, its downfalls and also gives a future perspective on how the landscape should change to allow BC to be utilised in wound care in the current environment.
Superclear, Porous Cellulose Membranes with Chitosan-Coated Nanofibers for Visualized Cutaneous Wound Healing Dressing.
Xia Jian,Zhang Hao,Yu Faquan,Pei Ying,Luo Xiaogang
ACS applied materials & interfaces
Easy and rapid continuous large-scale industrial production of transparent visualized cutaneous wound healing dressing from natural polymers is very worth studying in medical natural polymer materials and multifunction gauze dressing design fields. In this work, superclear, porous cellulose membranes (CMs) with chitosan-coated nanofibers were fabricated using a simple, one-step electrostatic spinning technology and evaluated as potential wound dressings. First, the pure CMs were dissolved by a simple physical method, and then, the membranes were regenerated in an acidic coagulation bath by the casting method. The chitosan solution was polarized into nanofibers and formed a continuous fiber mat on CMs because of the charge repulsion between molecules. The prepared chitosan-coated CMs (CM-CS) were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, tensile tests, and so forth. The results indicated that CM-CS showed high wettability, hydrophilicity, and gas permeability, in addition to excellent light transmittance and mechanical compliance. Cell cytotoxicity and morphology assay and antibacterial activity against and were also studied. They exhibited good biocompatibility and antibacterial activity of CM-CS. Moreover, evaluation of an in vivo wound healing model in mice revealed that CM-CS had a good effect in promoting wound healing. This work provided an easy and rapid continuous large-scale industrial design strategy for natural bioresource-based wound dressing materials, which could act as potential wound dressings for clinical use.
Engineering Bacterial Cellulose by Synthetic Biology.
Singh Amritpal,Walker Kenneth T,Ledesma-Amaro Rodrigo,Ellis Tom
International journal of molecular sciences
Synthetic biology is an advanced form of genetic manipulation that applies the principles of modularity and engineering design to reprogram cells by changing their DNA. Over the last decade, synthetic biology has begun to be applied to bacteria that naturally produce biomaterials, in order to boost material production, change material properties and to add new functionalities to the resulting material. Recent work has used synthetic biology to engineer several strains; bacteria that naturally secrete large amounts of the versatile and promising material bacterial cellulose (BC). In this review, we summarize how genetic engineering, metabolic engineering and now synthetic biology have been used in strains to alter BC, improve its production and begin to add new functionalities into this easy-to-grow material. As well as describing the milestone advances, we also look forward to what will come next from engineering bacterial cellulose by synthetic biology.
Antibacterial Activity of Bacterial Cellulose Loaded with Bacitracin and Amoxicillin: In Vitro Studies.
Lemnaru Popa Georgiana-Mădălina,Truşcă Roxana Doina,Ilie Cornelia-Ioana,Țiplea Roxana Elena,Ficai Denisa,Oprea Ovidiu,Stoica-Guzun Anicuța,Ficai Anton,Dițu Lia-Mara
Molecules (Basel, Switzerland)
The use of bacterial cellulose (BC) in skin wound treatment is very attractive due to its unique characteristics. These dressings' wet environment is an important feature that ensures efficient healing. In order to enhance the antimicrobial performances, bacterial-cellulose dressings were loaded with amoxicillin and bacitracin as antibacterial agents. Infrared characterization and thermal analysis confirmed bacterial-cellulose binding to the drug. Hydration capacity showed good hydrophilicity, an efficient dressing's property. The results confirmed the drugs' presence in the bacterial-cellulose dressing's structure as well as the antimicrobial efficiency against and . The antimicrobial assessments were evaluated by contacting these dressings with the above-mentioned bacterial strains and evaluating the growth inhibition of these microorganisms.
A Note on an Improved Self-Healing Group Key Distribution Scheme.
Guo Hua,Zheng Yandong,Wang Biao,Li Zhoujun
Sensors (Basel, Switzerland)
In 2014, Chen et al. proposed a one-way hash self-healing group key distribution scheme for resource-constrained wireless networks in the journal of Sensors (14(14):24358-24380, doi: 10.3390/ s141224358). They asserted that their Scheme 2 achieves mt-revocation capability, mt-wise forward secrecy, any-wise backward secrecy and has mt-wise collusion attack resistance capability. Unfortunately, this paper pointed out that their scheme does not satisfy the forward security, mt-revocation capability and mt-wise collusion attack resistance capability.
Antimicrobial and wound healing properties of a bacterial cellulose based material containing cells.
Savitskaya I S,Shokatayeva D H,Kistaubayeva A S,Ignatova L V,Digel I E
A biocomposite composed of bacterial cellulose (BC) gel-film and (BS) cells was obtained and characterized with a view to future biomedical applications. The inclusion of functional ingredient (10/g viable BS cells) in the composite was carried out by their joint aggregation with the BC gel-film. Immobilized BS cells displayed high antagonistic activity towards causative agents of wound infections such as , . Application of the BC/BS-biocomposite for the treatment of excision wounds, performed on laboratory animals, stimulated reparative processes and shortened the healing time. Possible mechanisms of the wound-healing effect of BC/BS gel films are discussed. In this work we claim that the developed BC/BS-material can be positioned as a universal wound coating and sanitary-hygienic product.
Increased Serum Level of Interleukin-10 Predicts Poor Survival and Early Recurrence in Patients With Peripheral T-Cell Lymphomas.
Zhang Yan,Zheng Yanlong,Shou Lihong,Shi Yuanfei,Shen Huafei,Zhu Mingyu,Ye Xiujin,Jin Jie,Xie Wanzhuo
Frontiers in oncology
Peripheral T cell lymphoma (PTCL) is an alloplasm group of aggressive and lymphoproliferative tumors with heterogeneous morphological changes of mature T cell immunophenotype. It has multiple subtypes and most of them have poor prognosis. Interleukin 10 (IL-10) is one kind of multi-cell-derived and multifunctional cytokine. It regulates the growth and differentiation of cells, participates in inflammation and immune response, plays an important role in tumor and infection, and is closely related to blood system diseases. Therefore, we implemented a retrospective study of 205 patients who were newly diagnosed with PTCL to explore the relationship between IL-10 and prognosis and early recurrence. We found patients with IL-10 ≥3.6 pg/ml achieved a lower CR rate and higher 1-year recurrence rate than patients with IL-10 <3.6 pg/ml (14.4 vs. 51.9%; 17.6 vs. 49.5%). On multivariate analysis, moreover, elevated IL-10 is an extremely important prognostic factor in PTCL, which can lead to worsening of overall survival (OS), low complete response (CR) rate and higher early relapse rate. Therefore, measurement of IL-10 levels in peripheral blood at the initial stage are useful for predicting the prognosis and helping us to make different treatment plans for individual patients. In the near future, IL-10 inhibitors or antagonists may become a new method of immunotargeting therapy for patients with PTCL.
Microbial cellulose dressing compared with silver sulphadiazine for the treatment of partial thickness burns: A prospective, randomised, clinical trial.
Aboelnaga Ahmed,Elmasry Moustafa,Adly Osama A,Elbadawy Mohamed A,Abbas Ashraf H,Abdelrahman Islam,Salah Omar,Steinvall Ingrid
Burns : journal of the International Society for Burn Injuries
BACKGROUND:The current treatment for partial thickness burns at the trial site is silver sulphadiazine, as it minimises bacterial colonisation of wounds. Its deleterious effect on wound healing, together with the need for repeated, often painful, procedures, has brought about the search for a better treatment. Microbial cellulose has shown promising results that avoid these disadvantages. The aim of this study was therefore to compare microbial cellulose with silver sulphadiazine as a dressing for partial thickness burns. METHOD:All patients who presented with partial thickness (superficial and deep dermal) burns from October 2014 to October 2016 were screened for this randomised clinical trial. Twenty patients were included in each group: the cellulose group was treated with microbial cellulose sheets and the control group with silver sulphadiazine cream 10mg/g. The wound was evaluated every third day. Pain was assessed using the Face, Legs, Activity, Cry, Consolability (FLACC) scale during and after each procedure. Other variables recorded were age, sex, percentage total body surface area burned (TBSA%), clinical signs of infection, time for epithelialisation and hospital stay. Linear multivariable regression was used to analyse the significance of differences between the treatment groups by adjusting for the size and depth of the burn, and the patient's age. RESULTS:Median TBSA% was 9% (IQR 5.5-12.5). The median number of dressing changes was 1 (IQR 1-2) in the cellulose group, which was lower than that in the control group (median 9.5, IQR 6-16) (p<0.001). Multivariable regression analysis showed that the group treated with microbial cellulose spent 6.3 (95% CI 0.2-12.5) fewer days in hospital (p=0.04), had a mean score that was 3.4 (95% CI 2.5-4.3) points lower during wound care (p<0.001), and 2.2 (95% CI 1.6-2.7) afterwards (p<0.001). Epithelialisation was quicker, but not significantly so. CONCLUSION:These results suggest that the microbial cellulose dressing is a better first choice for treatment of partial thickness burns than silver sulphadiazine cream. Fewer dressings of the wound were done and, combined with the low pain scores, this is good for both the patients and the health care system. The differences in randomisation of the area of burns is, however, a concern that needs to be included in the interpretation of the results.
Extraction, characterization, utilization as wound dressing and drug delivery of Bletilla striata polysaccharide: A review.
Chen Ziyan,Cheng Lizeng,He Yichen,Wei Xinlin
International journal of biological macromolecules
This review provides updated information on a kind of active polysaccharides extracting from Chinese traditional herb Bletilla striata. Preliminary investigations have listed several isolation approaches of extracting Bletilla striata polysaccharide (BSP) and the characterization result showed that the backbone of BSP has mainly consisted of 1,4-linked mannosyl residues and 1,4-linked glucosyl residues. Remarkably, this review sums up the exploitation of BSP as biomaterials, including the preparation, bioactivity and effect mechanism of BSP-based wound dressings and drug deliveries. BSP exhibits excellent healing function mainly due to its modulation of macrophages throughout inflammation and proliferation periods. BSP-based drug vehicles include micelles, nanoparticles, microspheres and microneedles which display anti-cancer functions of targeted delivering drugs and drug capability of itself as well. This review aims to pave the way for further exploitation of this compound in biomedical area.