Restructuring of poly(2-ethyl-2-oxazoline)/tannic acid multilayers into fibers. Adatoz E Beruhil,Hendessi S,Ow-Yang C W,Demirel A L Soft matter H-Bonded, pH-responsive poly(2-ethyl-2-oxazoline) (PEOX) and tannic acid (TA) multilayers were prepared by layer-by-layer deposition. Free-floating PEOX/TA multilayers were shown to restructure in a pH3 phosphate buffer solution to H-bonded, pH-responsive PEOX/TA fibers. This restructuring was also evident during the growth of multilayers thicker than 15 bilayers (BL). The growth profile of 30 BL-thick films showed a significant decrease in the film thickness from 118 nm to 85 nm between 15 BL and 20 BL, after which the growth trend was regained with some small fluctuations. This decrease was associated with the detachment of film patches from the top surface of the film. The rinse solutions consisted of fibrous aggregates, which were formed by the restructuring of the detached multilayer patches. These fibers were characterized by TGA, XPS, FTIR and SEM measurements which showed that the fibers consisted of H-bonded PEOX and TA molecules. As such, the fibers were pH-responsive and disintegrated at pH > 8.5. Scanning electron microscopy images indicated that the fibers might have been formed by the curling of planar LbL film patches and the dried fibers looked like collapsed hollow tubes on solid substrates. These results contribute to our understanding of the stability of LbL films in various chemical conditions and the ways to modify the morphology of self-assembled structures. pH-responsive fibrous aggregates are important in a variety of biomedical applications, from controlled release to sensors. 10.1039/c8sm00381e
    Multifunctional Tannic Acid (TA) and Lysozyme (Lys) Films Built Layer by Layer for Potential Application on Implant Coating. Yang Shuoshuo,Wang Yong,Wu Xiaoxiao,Sheng Sunren,Wang Tian,Zan Xingjie ACS biomaterials science & engineering A multifunctional (TA/Lys) film, featuring good antioxidant property, fast cell attachment at the initial stage, enhanced osteogenesis, and broad-spectrum antibacterial property, was constructed by the layer-by-layer (LBL) method. The building process was monitored by quartz crystal microbalance with dissipation (QCM-D); the physical properties, such as topography, stiffness in dry and liquid state, and conformation of Lys in the film, were thoroughly characterized. These physical properties were modulated by varying the salt concentration at which the film was constructed. The film not only allows for favorable cell attachment and proliferation of preosteoblasts Mc3t3-E1 but also provides antibacterial property against Gram-positive bacteria, and , and Gram-negative bacteria, . It also displays good antioxidant property, which plays a critical role on fast cell attachment at the initial stage. 10.1021/acsbiomaterials.9b00717
    Biocompatible and biodegradable poly(Tannic Acid) hydrogel with antimicrobial and antioxidant properties. Sahiner Nurettin,Sagbas Selin,Sahiner Mehtap,Silan Coskun,Aktas Nahit,Turk Mustafa International journal of biological macromolecules A novel resourceful bulk poly(Tannic Acid) (p(TA)) hydrogel was prepared by crosslinking TA molecules with an epoxy crosslinker, trimethylolpropane triglycidyl ether (TMPGDE), in an autoclave at 90°C for 2h. The obtained p(TA) hydrogels were in disk form and have highly porous morphology. The swelling characteristics of p(TA) hydrogels were investigated in wound healing pH conditions of pH 5.4, 7.4, and 9 at 37.5°C, and the hydrogels showed good swelling and moisture content behavior. Especially, p(TA) hydrogels were found to be sensitive to pH 9 with 1669% maximum swelling. P(TA) hydrogels were completely degraded at pH 9 hydrolytically in 9 days. Total phenol contents and the effects of scavenging ABTS(+) radicals of degraded p(TA) hydrogels at pH 5.4, 7.4, and 9 were evaluated and calculated in terms of gallic acid equivalent and trolox equivalent antioxidant capacity, respectively, and found to be very effective. Moreover, degraded p(TA) hydrogels display strong antimicrobial behavior against gram positive Staphylococcus aureus, Bacillus subtilis, gram negative Pseudomonas aeruginosa bacteria strains and Candida albicans fungus strain. The WST-1 results indicated that bulk p(TA) hydrogels have no cyctotoxicity to the L929 fibroblast cell line in vitro. 10.1016/j.ijbiomac.2015.10.057
    Chitosan, gelatin and methylcellulose films incorporated with tannic acid for food packaging. Halim Al Luqman Abdul,Kamari Azlan,Phillip Esther International journal of biological macromolecules In this work, chitosan, gelatin and methylcellulose films incorporated with tannic acid (TA) were synthesised, characterised and applied for the first time to preserve cherry tomatoes (Solanum lycopersicum var. cerasiforme) and grapes (Vitis vinifera). The addition of TA at 15% (w/w) increased the transparency value of biopolymer films. The highest increment of transparency value was obtained for MC-TA film, increased from 0.572 to 4.73 A/mm. Based on antimicrobial study, the addition of TA improved the antibacterial properties of biopolymers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The ability of films to preserve both fruits was evaluated in a 14-day preservation study. The application of biopolymer films treated with TA has decreased the weight loss and browning index of fruits, as compared to control films. A significant reduction in the weight loss of cherry tomatoes wrapped with chitosan (from 21.3 to 19.6%), gelatin (from 22.1 to 15.5%) and methylcellulose (26.2 to 20.5%) films were obtained following TA treatment. Overall, results obtained from this study highlight the effects of TA on physiochemical properties of biopolymer films and their ability to preserve fruits. 10.1016/j.ijbiomac.2018.08.169
    Galloyl groups-regulated fibrinogen conformation: Understanding antiplatelet adhesion on tannic acid coating. Yang Liwei,Han Lulu,Liu Qi,Xu Yige,Jia Lingyun Acta biomaterialia Fibrinogen (Fgn) has been identified as the key protein in the process of biomaterial-induced platelet adhesion. We have recently reported a facile and effective method for constructing platelet-repellent surface using a natural polyphenol component tannic acid (TA). However, the mechanism by which the TA surface repels platelets was not fully understood. To address this issue, we investigated the adsorption of Fgn (amount and conformation) on four TA-functionalized surfaces with different amounts of galloyl groups and the potential for platelet adherence on these surfaces. The experimental results indicated that the four TA-functionalized surfaces adsorbed a similar amount of Fgn, but the conformation and bioactivity of the adsorbed Fgn and the subsequent platelet adherence were quite different among the surfaces. The TA surface with the most galloyl groups induced minimal changes in the conformation of Fgn, a result of the α and γ chains of the adsorbed Fgn being highly inactive on the surface, thus leading to an outstanding antiplatelet adhesion performance. With a decreased amount of galloyl groups, the activity of the α chain in the adsorbed Fgn remained unchanged, but the activity of the γ chain and the extent of platelet adhesion gradually increased. This work provided a new concept for controlling platelet adhesion on solid materials, and we envision that the TA film could have potential applications in the development of new blood-contacting biomaterials in the future. STATEMENT OF SIGNIFICANCE:Reducing platelet adhesion on material surfaces is of tremendous scientific interest in the field of blood-contacting biomaterials, but it remains a big challenge due to the highly adhesive nature of the platelets. In this study, we demonstrated for the first time that tannic acid surface with abundant galloyl groups could induce minimal conformational changes of fibrinogen, eventually leading to an outstanding antiplatelet adhesion effect. In addition, the platelet adhesion response could be easily controlled through regulating the amount of galloyl groups on the surface. This work provided a new strategy for controlling platelet adhesion on solid materials, which was totally different from existing methods such as construction of physically patterned surfaces, modification of inert hydrophilic polymers or appending bioactive moieties to target surfaces. 10.1016/j.actbio.2017.09.034
    Studies on the Drug Loading and Release Profiles of Degradable Chitosan-Based Multilayer Films for Anticancer Treatment. Sun Hyeongdeok,Choi Daheui,Heo Jiwoong,Jung Se Yong,Hong Jinkee Cancers This study demonstrates the possibility of developing a rapidly degradable chitosan-based multilayer film for controlled drug release. The chitosan (CHI)-based multilayer nanofilms were prepared with three different types of anions, hyaluronic acid (HA), alginic acid (ALG) and tannic acid (TA). Taking advantage of the Layer-by-Layer (LBL) assembly, each multilayer film has different morphology, porosity and thickness depending on their ionic density, molecular structure and the polymer functionality of the building blocks. We loaded drug models such as doxorubicin hydrochloride (DOX), fluorescein isothiocyanate (FITC) and ovalbumin (Ova) into multilayer films and analyzed the drug loading and release profiles in phosphate-buffered saline (PBS) buffer with the same osmolarity and temperature as the human body. Despite the rapid degradation of the multilayer film in a high pH and salt solution, the drug release profile can be controlled by increasing the functional group density, which results in interaction with the drug. In particular, the abundant carboxylate groups in the CHI/HA film increased the loading amount of DOX and decreased rapid drug release. The TA interaction with DOX via electrostatic interaction, hydrogen bonding and hydrophobic interaction showed a sustained drug release profile. These results serve as principles for fabricating a tailored multilayer film for drug delivery application. 10.3390/cancers12030593
    Improving Sodium Alginate Films Properties by Phenolic Acid Addition. Kaczmarek Beata Materials (Basel, Switzerland) Currently, packaging materials constitute a group of the most commonly used products. Natural polymers are widely tested as potential packaging materials to replace traditional plastics. Sodium alginate is eco-friendly and reveals effective film-forming properties whereas tannic acid has been proposed as a sodium alginate cross-linker. Thin films of sodium alginate/tannic acid were obtained by solvent evaporation. Interactions between the components were determined as well as the maximum tensile strength and color change after contact with different solutions. Improvement in the physicochemical properties of the obtained films was noticed. Moreover, such films showed antioxidant properties. It may be assumed that materials based on a sodium alginate/tannic acid mixture are promising alternatives to traditional packaging materials. 10.3390/ma13132895
    Layer-by-layer deposition of tannic acid and Fe³⁺ cations is of electrostatic nature but almost ionic strength independent at pH 5. Ringwald Christian,Ball Vincent Journal of colloid and interface science The step-by-step assembly of tannic acid (TA) and of Fe(3+) cations allows to produce films of controlled thickness using exclusively small multivalent ions. In the present investigation, it is shown that even if electrostatic interactions are dominant over ligand to metal charge transfer interactions in stabilizing such films, those electrostatic interactions display a small sensitivity to concentration in NaCl used as a supporting electrolyte as well as to the concentration in sodium acetate in the absence of NaCl. This finding highlights the strong stability of the films obtained through the step-by-step deposition of TA and Fe(3+) cations. Complementarily, the films made from 6 deposition cycles of TA and Fe(3+) cations do not form Prussian Blue when put in contact with hexacyanoferrate anions. This shows that Fe(3+) is so tightly bound to the film that it is not able to form a coordination polymer with Fe(CN)6(4-) anions. 10.1016/j.jcis.2015.03.009
    Hydrogen bonded multilayer films based on poly(2-oxazoline)s and tannic acid. Sundaramurthy Anandhakumar,Vergaelen Maarten,Maji Samarendra,Auzély-Velty Rachel,Zhang Zhiyue,De Geest Bruno G,Hoogenboom Richard Advanced healthcare materials In recent years, the layer-by-layer (LbL) assembly based on hydrogen bonding interactions is gaining popularity for the preparation of thin film coatings, especially for biomedical purposes, based on the use of neutral, non-toxic building blocks. The use of tannic acid (TA) as hydrogen bonding donor is especially interesting as it results in LbL films that are stable under physiological conditions. In this work, investigations on the LbL thin film preparation of TA with poly(2-oxazoline)s with varying hydrophilicity, namely poly(2-methyl-2-oxazoline) (PMeOx), poly(2-ethyl-2-oxazoline) (PEtOx) and poly(2-n-propyl-2-oxazoline) (PnPropOx), are reported. The LbL assembly process is investigated by quartz crystal microbalance and UV-vis spectroscopy revealing linear growth of the film thickness. Furthermore, isothermal titration calorimetry demonstrates the LbL assembly of TA, and PMeOx is found to be mostly enthalpy driven while the LbL assembly of TA with PEtOx and PnPropOx is mostly entropy driven. Finally, scanning electron microscopy and ellipsometry demonstrate the formation of smooth thin films for LbL assembly of TA with all three polymers. Such poly(2-oxazoline) coatings have high potential for use as anti-biofouling coatings. 10.1002/adhm.201400377
    Applications of tannic acid in membrane technologies: A review. Yan Wentao,Shi Mengqi,Dong Chenxi,Liu Lifen,Gao Congjie Advances in colloid and interface science Today, membrane technologies play a big role in chemical industry, especially in separation engineering. Tannic acid, one of the most famous polyphenols, has attracted widespread interest in membrane society. In the past several years, researches on the applications of tannic acid in membrane technologies have grown rapidly. However, there has been lack of a comprehensive review for now. Here, we summarize the recent developments in this field for the first time. We comb the history of tannic acid and introduce the properties of tannic acid firstly, and then we turn our focus onto the applications of membrane surface modification, interlayers and selective layers construction and mixed matrix membrane development. In those previous works, tannic acid has been demonstrated to be capable of making a great contribution to the membrane science and technology. Especially in membrane surface/interface engineering (such as the construction of superhydrophilic and antifouling surfaces and polymer/nanoparticle interfaces with high compatibility) and development of thin film composite membranes with high permselectivity (such as developing thin film composite membranes with ultrahigh flux and high rejection), tannic acid can play a positive and great role. Despite this, there are still many critical challenges lying ahead. We believe that more exciting progress will be made in addressing these challenges in the future. 10.1016/j.cis.2020.102267
    Multilayered films made from tannic acid and alkaline phosphatasewith enzymatic activity and electrochemical behavior. Allais Manon,Meyer Florent,Ball Vincent Journal of colloid and interface science Layer-by-layer-deposition of enzymes and polyphenols, like tannic acid may provide a reservoir of antioxidant and antibacterial molecules of controlled thickness and degradability with an additional activity due to the presence of the enzyme. The layer-by-layer deposition of films made from tannic acid and alkaline phosphatase is shown to yield an exponential growth with the number of deposited layer pairs. The films display the electrochemical behavior of tannic acid and the enzymatic activity of alkaline phosphatase. However, it is shown that only the enzyme close to the film-solution interface is active and follows the Michaelis-Menten mechanism. Similarly, only tannic acid close to the electrode-film interface can be oxidized. The enzymatic activity is almost completely lost when the multilayer film is treated with sodium periodate which oxidizes tannic acid even if the solubilized enzyme is not affected by the oxidant. This shows that the formation of covalent bonds between alkaline phosphatase and tannic acid is deleterious for its conformation and activity. 10.1016/j.jcis.2017.10.101
    In-situ coating TiO surface by plant-inspired tannic acid for fabrication of thin film nanocomposite nanofiltration membranes toward enhanced separation and antibacterial performance. Li Tong,Xiao Yirong,Guo Dongxue,Shen Liguo,Li Renjie,Jiao Yang,Xu Yanchao,Lin Hongjun Journal of colloid and interface science A major issue hindering development of thin film nanocomposite (TFN) nanofiltration (NF) membrane is the interfacial defects induced by nanomaterial aggregation in top layer. Although various nanomaterials surface modification strategies have been developed to eliminate the interfacial defects, they usually involve extra modification steps and complex post-treatments. Inspired by the substrate-independent coating ability of tannic acid (TA) and the fact that the phenolic hydroxyl groups in TA can react with acyl chloride group in trimesoyl chloride, a TA coating solution containing TiO nanoparticles was used as an aqueous phase of interfacial polymerization to prepare interfacial modified TFN NF membranes in this study. Surface modification of TiO nanoparticles and interfacial polymerization can be carried out in a single step without any extra pre-modification step. It was found that the TA coating on TiO nanoparticles surface could decrease TiO aggregations and enhance interfacial compatibility between TiO and polyester matrix. The TFN NF membrane prepared at a TiO loading of 0.020 wt% exhibited a pure water flux of 28.8 L m h (284% higher than that of the controlled TFC membrane), and possessed enhanced NaCl and NaSO rejections of 57.9% and 94.6%, respectively, breaking through the trade-off between permeability and selectivity. 10.1016/j.jcis.2020.03.087
    Temperature-triggered on-demand drug release enabled by hydrogen-bonded multilayers of block copolymer micelles. Zhu Zhichen,Gao Ning,Wang Hongjun,Sukhishvili Svetlana A Journal of controlled release : official journal of the Controlled Release Society We report on hydrogen-bonded layer-by-layer (LbL) films as a robust, reusable platform for temperature-triggered "on-demand" release of drugs. Films with high drug loading capacity, temperature-controlled on-off drug release, and stability at physiological conditions were enabled by assembly of tannic acid (TA) with temperature-responsive block copolymer micelles (BCMs), which were pre-formed by heating solutions of a neutral diblock copolymer, poly(N-vinylpyrrolidone)-b-poly(N-isopropylacrylamide) (PVPON-b-PNIPAM), to a temperature above the lower critical solution temperature (LCST) of PNIPAM. The BCM/TA films exhibited temperature-triggered swelling/deswelling transitions at physiological conditions (swelling ratios of 1.75 and 1.2 at 37°C and 20°C, respectively). A model drug, doxorubicin (DOX) was incorporated into the film at a high drug-to-matrix ratio (~9.3wt.% of DOX per film mass), with a total loading capacity controlled by the film thickness. At 37°C, DOX was efficiently retained within the hydrophobic BCM cores of BCM/TA films, whereas exposure to a lower temperature (20°C) triggered fast DOX release. While neither bare BCM-containing films nor films loaded with DOX showed cytotoxicity at 37°C, drug released from films at lower temperature exhibited high potency against breast cancer cells. Repeated on/off drug release was demonstrated with 1.5-μm-thick DOX-loaded films, allowing at least three 30-min cooling cycles with consistent DOX (~12-16% of loaded DOX released for each cycle) released over a 4-day period. Despite significant stress associated with multiple swelling/deswelling cycles, films maintained their structural integrity in PBS, and each film could be repeatedly loaded with drug and used more than 15 times with only ~7% loss in film thickness and no obvious changes in reloading capacity or release profiles. This work presents the first proof-of-concept utility of temperature-responsive BCM-containing films for repeated on-demand release of a drug. 10.1016/j.jconrel.2013.06.031
    Fabrication of strong hydrogen-bonding induced coacervate adhesive hydrogels with antibacterial and hemostatic activities. Zhang Dongfei,Xu Ziyang,Li Haofei,Fan Chuanchuan,Cui Chunyan,Wu Tengling,Xiao Meng,Yang Yang,Yang Jianhai,Liu Wenguang Biomaterials science In this work, a biocompatible poly(N-hydroxyethyl acrylamide) (PHEAA) polymer with hydrogen bonding acceptors and donors in its side chains is prepared and mixed with tannic acid (TA) to form a supramolecular coacervate hydrogel (TAHE) due to multiple hydrogen-bonding interactions between TA and PHEAA. The coacervate TAHE hydrogel exhibits not only self-healing and antibacterial properties, but also strong adhesion to various substrates, with average adhesion strengths of 722 kPa, 522 kPa, 484 kPa, and 322 kPa to the substrates of iron, PMMA, ceramics, and glass, respectively. Notably, the hydrogel reformed by the rehydration of freeze-dried and ground TAHE hydrogel powder retains the initial adhesive performance and exhibits an excellent hemostatic ability. This novel adhesive hydrogel holds great potential as an adhesive hemostatic material for self-rescue in emergency situations. 10.1039/c9bm02029b
    Tough polyacrylamide-tannic acid-kaolin adhesive hydrogels for quick hemostatic application. Fan Xianmou,Wang Shaobing,Fang Yan,Li Peiyuan,Zhou Weikang,Wang Zhengchao,Chen Mingfeng,Liu Haiqing Materials science & engineering. C, Materials for biological applications Adhesive hydrogels for wet and dynamic tissues are important for biomedical applications in order to withstand cyclic loading such as in the case of hemorrhaging control on the curved skins and heart tissues. However, the fabrication of hydrogels with strong mechanical properties, high adhesion strength, and hemostatic efficiency remains a big challenge. Inspired by the great adhesive behavior of mussels and Arion subfuscus, novel adhesive and hemostatic polyacrylamide-tannic acid-kaolin (PAAm-TA-KA) hydrogels were reported in this work. The hydrogels displayed high strength and toughness due to their physical and chemical crosslinking structures. The abundant catechol groups on tannic acid endow the hydrogels with strong and durable adhesion strength of up to 500 kPa on porcine skin. When applied onto human skin, the hydrogels could be easily peeled off without leaving any remains and causing any damages. The kaolin nanoparticles incorporated in the PAAm-TA-KA hydrogels not only served as a physical crosslinking agent, but an activator of the blood clotting factor FXII for accelerating the formation of thrombus. The strong tissue adhesion and blood coagulant potential of the PAAm-TA-KA hydrogels imparted them high hemostatic efficiency. The free-standing, adhesive, tough, cytocompatible, and hemostatic hydrogels are highly promising for traumatic bleeding control materials. 10.1016/j.msec.2020.110649
    Enhancement of antioxidant and antibacterial properties for tannin acid/chitosan/tripolyphosphate nanoparticles filled electrospinning films: Surface modification of sliver nanoparticles. Zhan Fuchao,Sheng Feng,Yan Xiangxing,Zhu Yingrui,Jin Weiping,Li Jing,Li Bin International journal of biological macromolecules The tannin acid/chitosan/tripolyphosphate nanoparticles were encapsulated in polyvinyl alcohol (PVA)/poly-acrylic acid (PAA) electrospinning films by electrostatic spinning technology. To optimize the prepared condition, properties and morphology of nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). The optimized initial concentration of tannin, chitosan and tripolyphosphate solutions were 1, 1, 0.5mg/ml, respectively, with adding proportion for 5:5:1. The average diameter of tannin acid/chitosan/tripolyphosphate nanoparticles was ∼80nm. The electrospinning films showed an excellent water-resistant property with 0.5wt%N,N'-Methylenebisacrylamide (MBA). Due to the antioxidant and antibacterial of tannic acid, the films possessed these properties. The antioxidant and antibacterial of these fibers significantly improved after in situ formation of silver nanoparticles (AgNPs). Electrospun films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). 10.1016/j.ijbiomac.2017.06.114