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Stimuli‐responsive materials exhibiting exceptional room temperature phosphorescence (RTP) hold promise for emerging technologies. However, constructing such systems in a sustainable, scalable, and processable manner remains challenging. This work reports a bio‐inspired strategy to develop RTP nanofiber materials using bacterial cellulose (BC) via bio‐fermentation. The green fabrication process, high biocompatibility, non‐toxicity, and abundant hydroxyl groups make BC an ideal biopolymer for constructing durable and stimuli‐responsive RTP materials. Remarkable RTP performance is observed with long lifetimes of up to 1636.79 ms at room temperature. Moreover, moisture can repeatedly quench and activate phosphorescence in a dynamic and tunable fashion by disrupting cellulose rigidity and permeability. With capabilities for repeatable moisture‐sensitive phosphorescence, these materials are highly suitable for applications such as anti‐counterfeiting and information encryption. This pioneering bio‐derived approach provides a reliable and sustainable blueprint for constructing dynamic, scalable, and processable RTP materials beyond synthetic polymers. [ABSTRACT FROM AUTHOR]

Abstract Stimuli‐responsive materials exhibiting exceptional room temperature phosphorescence (RTP) hold promise for emerging technologies. However, constructing such systems in a sustainable, scalable, and processable manner remains challenging. This work reports a bio‐inspired strategy to develop RTP nanofiber materials using bacterial cellulose (BC) via bio‐fermentation. The green fabrication process, high biocompatibility, non‐toxicity, and abundant hydroxyl groups make BC an ideal biopolymer for constructing durable and stimuli‐responsive RTP materials. Remarkable RTP performance is observed with long lifetimes of up to 1636.79 ms at room temperature. Moreover, moisture can repeatedly quench and activate phosphorescence in a dynamic and tunable fashion by disrupting cellulose rigidity and permeability. With capabilities for repeatable moisture‐sensitive phosphorescence, these materials are highly suitable for applications such as anti‐counterfeiting and information encryption. This pioneering bio‐derived approach provides a reliable and sustainable blueprint for constructing dynamic, scalable, and processable RTP materials beyond synthetic polymers.

The aim of this study was to develop highly pH-sensitive bacterial cellulose nanofibers/gelatin-based intelligent films, where the intelligent films were loaded with different ratios (10:0, 0:10 2:8, 5:5 and 8:2, w/w) of curcumin:anthocyanin (Cur/ATH), and the characterization of intelligent films was investigated. The results showed that the microstructures of intelligent films were much rougher as the proportion of curcumin increased. FTIR results showed that anthocyanin and curcumin were fixed in gelatin matrix by hydrogen bonds. Moreover, XRD results showed that curcumin had a significant effect on the crystal structure of the films. Interestingly, films loaded with a Cur/ATH ratio of 5:5 had the best mechanical and antioxidant properties and a high pH-sensitivity property. Consequently, the bacterial cellulose nanofibers/gelatin-based intelligent films loaded with a Cur/ATH ratio of 5:5 were used for the packaging of fresh pork, displaying good fresh-keeping and freshness detection effects. Therefore, this study suggested that bacterial cellulose nanofibers/gelatin-based intelligent films have great potential in the fresh-keeping and freshness detection of meat. [ABSTRACT FROM AUTHOR]

In this study, bacterial cellulose nanofibers (BCNs) (0%, 1%, 2%, and 3%) were used as nanofillers to prepare gelatin‐based edible films, and their physical properties and fresh‐keeping performance were investigated. The microstructure observation showed that the BCNs were well dispersed in the gelatin‐based edible films and the surface roughness of the films increased with the increase of BCNs content. X‐ray diffraction and thermogravimetric analysis showed that the crystallinity and thermal stability of the film were significantly increased with the increase of BCNs. Fourier‐transform infrared spectroscopy analysis suggested that hydrogen bond interactions occurred between BCNs and gelatin polymers, leading to improved mechanical properties with the increase of BCNs content. Furthermore, the barrier performance was also improved with the increase of BCNs content, where gelatin‐based edible films with 2% BCNs showed the best mechanical property. Meanwhile, the gelatin‐based film‐forming solutions (FFSs) containing different BCNs were coated on the fresh‐cut apples and the corresponding fresh‐keeping performance was investigated. The results showed that the fresh‐keeping parameters of fresh‐cut apples coated with FFSs containing BCNs were better as compared with those of pure gelatin FFSs. Moreover, the fresh‐keeping parameters were improved with the increase of BCNs, especially the FFSs containing 2% BCNs that showed the best fresh‐keeping parameters. Therefore, BCNs, used as nanofillers, are an excellent enhancer to improve the fresh‐keeping performance of the gelatin‐based edible coating, showing a promising potential application in the food preservation field. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC)/polypyrrole (PPy) nanofibrous composites have been extensively studied in supercapacitors owing to their large specific surface area and excellent tensile strength. However, the inferior cycling stability due to structural pulverization of PPy impedes their potential applications. Herein, nanofibrous composite membranes of MXene, PPy and oxidized BC (TOBC) were prepared for flexible supercapacitor electrodes. The C6 primary hydroxyl groups of BC nanofibers were oxidized into aldehyde or carboxyl groups. Due to the enhanced interaction of TOBC with PPy and MXene, the TOBC nanofibers were horizontally wrapped on the MXene nanosheets and PPy was homogeneously deposited on the TOBC nanofibers. The flexible solid-state supercapacitors fabricated with the MXene@TOBC@PPy (TMP) electrodes achieved an areal specific capacitance of 928.9 mF cm−2 at 0.7 mA cm−2 and a capacitance retention of 85.5% after 5000 cycles. Therefore, the TMP electrodes could be a promising electrode material for flexible supercapacitors. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the influence of water as a co-solvent on the interaction between a polymerizable ionic liquid—choline acrylate (ChA)—and bacterial cellulose. Bacterial cellulose dispersed in ChA is a new type of UV-curable biopolymer-based ink that is a prospective material for the 3D printing of green composite ion-gels. Higher cellulose content in inks is beneficial for the ecological and mechanical properties of materials, and leads to increased viscosity and the yield stress of such systems and hampers printability. It was found that the addition of water results in (1) a decrease in the solvent viscosity and yield stress; and (2) a decrease in the stability of dispersion toward phase separation under stress. In this work, an optimal composition in the range of 30–40 wt% water content demonstrating 97–160 Pa of yield stress was found that ensures the printability and stability of inks. The rheological properties of inks and mechanical characteristics (0.7–0.8 MPa strength and 1.1–1.2 MPa Young's modulus) were obtained. The mechanism of influence of the ratio ChA/water on the properties of ink was revealed with atomic force microscopy, wide-angle X-ray diffraction studies of bacterial cellulose after regeneration from solvent, and computer simulation of ChA/water mixtures and their interaction with the cellulose surface. [ABSTRACT FROM AUTHOR]

[Display omitted] Porous carbons have been widely applied for capacitive energy storage, yet usually suffer from insufficient rate performance because of the sluggish ion transport kinetics in deep and multi-branched pores. Herein, we fabricated an interconnected microporous capacitive carbon (IMCC) by growing D (+)-glucosamine on bacterial cellulose (BC) nanofibers scaffold, followed by carbonization and activation. The BC nanofibers acted as a sacrificial template during pre-carbonization, facilitating the subsequent KOH permeation and homogeneous activation. By taking advantage of the interconnected microporous structure, the IMCC delivers a high capacitance of 302 F g−1 at 1 A g-1 and an excellent rate capability of 165 F g−1 at 100 A g-1 for aqueous supercapacitor, demonstrating its fast ion transport capability. Impressively, it also shows a superior gravimetric capacity of 177 mAh g-1 at 0.5 A g-1 and remains a high value of 72 mAh g-1 at 20 A g-1 as a cathode material for Zn-ion hybrid capacitor. This facile and cost-effective design strategy exhibits a great potential to construct carbohydrates-derived interconnected microporous carbon materials for high-rate energy storage. [ABSTRACT FROM AUTHOR]

Two polymerizable ionic liquids (or monomeric ionic liquids, mILs) namely 1-butyl-3-methylimidazolium and choline acrylates ([C4mim]A and ChA, respectively) were synthesized using the modified Fukumoto method from corresponding chlorides. The chemical structure of the prepared mILs was confirmed with FTIR and NMR study. Investigation of the thermal properties with DSC demonstrates that both mILs have a Tg temperature of about 180 K and a melting point around 310 K. It was shown that the temperature dependence of FTIR confirm the Tg to be below 200. Both mILs exhibited non-Newtonian shear thinning rheological behavior at shear rates >4 s−1. It was shown that [C4mim]A is able to dissolve bacterial cellulose (BC) leading to a decrease in its degree of polymerization and recrystallisation upon regeneration with water; although in the ChA, the crystalline structure and nanofibrous morphology of BC was preserved. It was demonstrated that the thixotropic and rheological properties of cellulose dispersion in ChA at room temperature makes this system a prospective ink for 3D printing with subsequent UV-curing. The 3D printed filaments based on ChA, containing 2 wt% of BC, and 1% of N,N′-methylenebisacrylamide after radical polymerization induced with 1% 2-hydroxy-2-methylpropiophenone, demonstrated Young's modulus 7.1 ± 1.0 MPa with 1.2 ± 0.1 MPa and 40 ± 5% of strength and ultimate elongation, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop highly pH-sensitive bacterial cellulose nanofibers/gelatin-based intelligent films, where the intelligent films were loaded with different ratios (10:0, 0:10 2:8, 5:5 and 8:2, w/w) of curcumin:anthocyanin (Cur/ATH), and the characterization of intelligent films was investigated. The results showed that the microstructures of intelligent films were much rougher as the proportion of curcumin increased. FTIR results showed that anthocyanin and curcumin were fixed in gelatin matrix by hydrogen bonds. Moreover, XRD results showed that curcumin had a significant effect on the crystal structure of the films. Interestingly, films loaded with a Cur/ATH ratio of 5:5 had the best mechanical and antioxidant properties and a high pH-sensitivity property. Consequently, the bacterial cellulose nanofibers/gelatin-based intelligent films loaded with a Cur/ATH ratio of 5:5 were used for the packaging of fresh pork, displaying good fresh-keeping and freshness detection effects. Therefore, this study suggested that bacterial cellulose nanofibers/gelatin-based intelligent films have great potential in the fresh-keeping and freshness detection of meat.

A comparative study of two cellulosic materials i.e., cotton fabrics and bacterial cellulose nanofibers (NBC), is reported as substrates for metal organic frameworks (MOF-199), to prepare micro and nanocomposites of cellulose@MOF-199 for CO2 capture. The CO2 uptake performance was investigated using gravimetric adsorption and desorption kinetics. NBC was an efficient substrate with full coverage and uniform distribution of MOF crystals observed in NBC@MOF-199 nanocomposite. The surface area for NBC@MOF-199 and Cotton@MOF-199 were 553.4 m2 g−1 and 168.9 m2 g−1, respectively. NBC@MOF-199 showed a high adsorption capacity (2.9 mmol g−1) at ambient temperature and pressure, followed by Cotton@MOF-199 (1.2 mmol g−1). The kinetic studies revealed that the adsorption process is controlled by film diffusion at lower temperatures, and by sorption to active sites at higher temperatures. The estimated thermodynamic parameters represent a spontaneous adsorption with low activation energies of adsorption/desorption, promising a fast adsorption and facilitated regeneration adsorbent system with minimum energy costs. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the influence of water as a co-solvent on the interaction between a polymerizable ionic liquid—choline acrylate (ChA)—and bacterial cellulose. Bacterial cellulose dispersed in ChA is a new type of UV-curable biopolymer-based ink that is a prospective material for the 3D printing of green composite ion-gels. Higher cellulose content in inks is beneficial for the ecological and mechanical properties of materials, and leads to increased viscosity and the yield stress of such systems and hampers printability. It was found that the addition of water results in (1) a decrease in the solvent viscosity and yield stress; and (2) a decrease in the stability of dispersion toward phase separation under stress. In this work, an optimal composition in the range of 30–40 wt% water content demonstrating 97–160 Pa of yield stress was found that ensures the printability and stability of inks. The rheological properties of inks and mechanical characteristics (0.7–0.8 MPa strength and 1.1–1.2 MPa Young’s modulus) were obtained. The mechanism of influence of the ratio ChA/water on the properties of ink was revealed with atomic force microscopy, wide-angle X-ray diffraction studies of bacterial cellulose after regeneration from solvent, and computer simulation of ChA/water mixtures and their interaction with the cellulose surface.

A practically helpful bioadhesion system can be developed for biomedical treatments by taking advantage of the antigen–antibody interaction in which an antibody binds to a protein with specific lock and key binding affinity. This study presents a new type of skin tissue adhesive system in which an involucrin antibody (SY5)‐conjugated bacterial cellulose nanofiber (BCNF) is bound to involucrin (IVL) in corneocytes of the stratum corneum. For this, the SY5 is covalently incorporated on the surface of carboxylate of 2,2,6,6‐tetramethylpiperidine‐1‐oxyl radical (TEMPO)‐oxidized BCNFs via the 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC)/N‐hydroxysuccinimide (NHS) coupling reaction. It is shown that the SY5‐conjugated BCNF (BCNFSY5) exhibits the antigen–antibody interaction with the IVL, eventually leading to effective adhesion to the skin surface. Moreover, it is demonstrated that the BCNF‐based skin adhesion promotes wound healing by basically providing a tissue environment where cell proliferation can occur actively. These results emphasize that the BCNFSY5 system could pave the way for developing a new type of tissue adhesive for skin tissue regeneration. [ABSTRACT FROM AUTHOR]

Cellulose is the most widely distributed polymer material in nature and is considered a low-cost, green and recyclable material. Because of its excellent mechanical, optical and thermal properties, people are interested in the research of cellulose-based flexible electronic devices. Among them, bacterial cellulose has a low fiber bundle size during the production process and is easier to process to obtain nanofibers. Hereby, in this study the composite thermoelectric film was prepared from bacterial cellulose nanofibers (BCNFs) and copper iodide (CuI), a low-toxicity thermoelectric material. Hydrophobic properties of the composite thermoelectric film were obtained by immersing in AKD emulsion. It showed good mechanical flexibility and high biocompatibility. CuI particles can be recovered successfully through cellulase simulating the degradation process, and the closed-loop of preparation-recycling can be completed. In addition, it achieves an open circuit voltage of 11.3 mV and output power of 2.76 nW at a temperature difference of 70 K. This work not only confirms the environmental protection of CuI/BCNF thermoelectric film, but also provides a strategy for the recycling of thermoelectric equipment. [ABSTRACT FROM AUTHOR]

Two polymerizable ionic liquids (or monomeric ionic liquids, mILs) namely 1-butyl-3-methylimidazolium and choline acrylates ([C4mim]A and ChA, respectively) were synthesized using the modified Fukumoto method from corresponding chlorides. The chemical structure of the prepared mILs was confirmed with FTIR and NMR study. Investigation of the thermal properties with DSC demonstrates that both mILs have a Tg temperature of about 180 K and a melting point around 310 K. It was shown that the temperature dependence of FTIR confirm the Tg to be below 200. Both mILs exhibited non-Newtonian shear thinning rheological behavior at shear rates >4 s−1. It was shown that [C4mim]A is able to dissolve bacterial cellulose (BC) leading to a decrease in its degree of polymerization and recrystallisation upon regeneration with water; although in the ChA, the crystalline structure and nanofibrous morphology of BC was preserved. It was demonstrated that the thixotropic and rheological properties of cellulose dispersion in ChA at room temperature makes this system a prospective ink for 3D printing with subsequent UV-curing. The 3D printed filaments based on ChA, containing 2 wt% of BC, and 1% of N,N′-methylenebisacrylamide after radical polymerization induced with 1% 2-hydroxy-2-methylpropiophenone, demonstrated Young’s modulus 7.1 ± 1.0 MPa with 1.2 ± 0.1 MPa and 40 ± 5% of strength and ultimate elongation, respectively.

The current work was aimed to prepare bacterial cellulose/poly vinyl alcohol (BC/PVA) wound dressings loaded with antibiotic which were prepared via freeze-thawing. The swelling ratio of BC/PVA hydrogels was in the range of 188–240%. The water loss percentage of BC was improved with the addition of PVA. 30% of the cumulative ampicillin delivery from BC/PVA hydrogels was achieved during 120 h suggesting significant role of PVA incorporation since 50% of ampicillin was released from BC after 24 h. BC/PVA hydrogels showed great antibacterial activity against E.coli and S. aureus. The results revealed that BC/PVA hydrogels presented great potential as wound dressings with high swelling ratio, low water loss percentage and slow antibiotic release properties. [ABSTRACT FROM AUTHOR]

With the rise of wearable devices, flexible sensors have received extensive attention and research due to their great potential in human health detection and joint motion. Here, a flexible fiber strain sensor is directly obtained by a common wet‐spinning method, which used thermoplastic polyurethane as the elastomer, carbon nanotubes, and graphene as conductive fillers by incorporating 2,2,6,6‐tetramethylpiperidine‐1‐oxyl oxidized bacterial cellulose nanofibers (BCN) as the dispersant and binding agent. The introduction of BCN can effectively improve the interaction between the polymer matrix and the conductive fillers, and bear a part of the tensile stress and the supporting force during the fiber formation, to form the porous structure, which can efficiently carry and transfer the tensile force. Under the synergistic effect of various components, the fiber strain sensor with wide response range (230%), high gauge factor values of 17.8 (0−70%), 326.6 (70−150%), and 1501.0 (150−230%), fast response time, and recovery time (≈100 ms), and long‐term cyclic stability (>10 000 cycles) are prepared. In the fiber sensor, the ideal combination of excellent strain sensing performance and flexible wearable characteristics has been realized which will be of great significance in the field of weaving, lightweight, and foldable electronic devices. [ABSTRACT FROM AUTHOR]

Natural polymer hydrogels are expected to be promising biomaterial because of its excellent biocompatibility and biodegradability, but they are soft and easily broken. Herein, the poly (γ-glutamic acid) (γ-PGA)/bacterial cellulose (BC) composite hydrogels with excellent mechanical properties were constructed by introducing bacterial cellulose. The γ-PGA/BC composite hydrogels were obtained by the covalent cross-linking of γ-PGA in the BC nanofibers suspensions. The γ-PGA/BC composite hydrogels exhibited excellent strength and toughness due to the more effective energy dissipation of hydrogen bonds network among BC nanofibers and γ-PGA hydrogel matrix and BC also acts as an enhancer. The compressive fracture strength and toughness of the γ-PGA/BC composite hydrogels could reach up to 5.72 MPa and 0.42 MJ/m3 respectively. Additionally, the tensile strength of γ-PGA/BC composite hydrogels were improved 8.16 times compared with γ-PGA single network hydrogels. More significantly, BC could disperse evenly in the γ-PGA hydrogels because of the hydrophilic nature of γ-PGA and BC nanofillers, which led to good interface compatibility. The result of cytotoxicity tests indicated that γ-PGA/BC composite hydrogels present excellent cytocompatibility, which suggested that the γ-PGA/BC composite hydrogels could serve as promising materials for many biomaterial related applications. Unlabelled Image • The γ-PGA/BC composite hydrogels exhibit excellent strength, toughness and cytocompatibility. • Bacterial cellulose nanofibers acted as both nanofillers and physical cross-linkers in the composite hydrogels. • Two methods of labeling were used to characterize the dispersion uniformity of bacterial cellulose nanofibers in hydrogels. [ABSTRACT FROM AUTHOR]

The present research aimed to study the nanofibers from bacterial cellulose (BC) by HCl hydrolysis and explore its new potential application in fresh-cut apples. Bacterial cellulose nanofibers (BCNs) showed low and more homogeneity particle size, as well as higher zeta potential and transparency in comparison with BC, which was confirmed by morphological analysis. Physical properties analysis showed that BCNs was more excellent semi-crystalline polymer with higher thermal stability as compared with BC. Rheological results displayed that BCNs suspensions presented a shear thinning behaviour with higher apparent viscosity, storage (G′) and loss (G′′) moduli at the same concentration in comparison with BC. Furthermore, BCNs suspensions were more stable than BC suspensions under storage condition of 4 °C. Additionally, 2% (wt%) of BCNs suspensions were coated on fresh-cut apples. Results showed that the samples coated with BCNs suspension displayed more excellent properties of keeping fresh-cut apples as compared with that coated with BC suspensions, including delaying weight loss, improving firmness and soluble solids content, reducing browning index and titratable acidity. Therefore, the low cost and high biocompatibility of BCNs can be used as new coatings for fresh-cut apples and have great potential to coat fresh-cut fruits and vegetables in food industry. [ABSTRACT FROM AUTHOR]

This study was aimed at developing edible films of konjac glucomannan (KGM) with different contents of bacterial cellulose nanofibers (BCNs). The effects of different contents of BCNs (0–4% (w/w)) on the properties of KGM-based edible films were investigated in the present work. The rheological properties showed that the film-forming solutions displayed an entanglement system with G′G″ at high frequencies. SEM indicated that BCNs were well dispersed in the BCNs/KGM films. With the increase of BCNs contents, the surface morphology of the films assessed by AFM displayed an increased trend in the surface roughness. Moreover, the films were formed mainly through hydrogen bonds as indicated by FTIR analysis. XRD, DSC and TGA showed that the crystallinity and the thermal stability of films increased with the increase of BCNs. Meanwhile, barrier properties of films were improved by the addition of BCNs. Additionally, with the increase of BCNs, the tensile strength (TS) of the films increased, while the elongation at break (EAB) was increased and then decreased. Therefore, reinforcement of KGM-based films with BCNs leads to enhance barrier and mechanical properties with promising potential as packaging films for food products. • BCNs were able to be well dispersed in KGM-based edible films. • The edible films were formed through hydrogen bonds between BCNs and KGM. • The physical properties of KGM-based films were improved by the addition of BCNs. • BCNs/KGM edible films showed great potential as packaging films for food products. [ABSTRACT FROM AUTHOR]

Cellulose composite nanopaper is extensively employed in flexible energy storage systems owing to their light weight, good flexibility and high specific surface area. Nevertheless, achieving flexible and ultrathin nanopaper supercapacitors with excellent electrochemical performance remains a challenge. Herein, surface cationization of bacterial cellulose (BC) nanofibers was conducted using 2,3-epoxypropyltrimethylammonium chloride (EPTMAC). Anion-doped polypyrrole (PPy) was incorporated onto the surface of the cationic bacterial cellulose (BCE) nanofibers by an interfacial electrostatic self-assembly process. The obtained PPy@BCE electrode exhibited excellent electrochemical performance, including an areal capacitance of 3988 mF cm−2 at 1.0 mA cm−2 and a capacitance retention of 97 % after 10,000 cycles. A laminated paper-forming strategy was adopted to design and fabricate all-in-one integrated flexible supercapacitors (IFSCs) using PPy@BCE nanopaper as electrodes and BC nanopaper as a separator. The IFSCs showed superior areal capacitance (3669 mF cm−2 at 1 mA cm−2), high energy density (193.7 μWh cm−2 at a power density of 827.3 μW cm−2), and outstanding mechanical flexibility (with no significant capacitance attenuation after repeatedly bending for 1000 times). The present strategy paves a way for the large-scale production of paper-based energy storage devices. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • TOBC nanofibers are used as "spacer" in rGO sheets and mechanical buffer layer in macrofibers. • The highly-winkled TOBC/rGO fibers has high electrical conductivity, which can reach 100.2 S cm−1 with 70% rGO concentration. • PPy@TOBC/rGO electrode delivers high capacitance of 391 F g−1 at 0.5 A g−1. • The FSC exhibits an energy density of 8.8 mWh cm−3 with high cycling and bending stability. Abstract The emerging fiber-based supercapacitors with high energy and power density are highly desirable for they provide strong support for the development of portable and wearable devices. Here, a flexible, binder-free high-performance fiber-based supercapacitors is structured based on hierarchical polypyrrole@TEMPO-oxidized bacterial cellulose/reduced graphene oxide macrofibers by wet spinning and in situ polymerization polypyrrole. For the synergistic effects of three components, the excellent specific capacitance of the electrode with 391 F g−1 (373 F cm−3) at the current density of 0.5 A g−1 (0.48 A cm−3) and the fiber-based supercapacitor made of the electrodes with 259 F g−1 (258 F cm−3) at the current density of 0.2 A g−1 (0.199 A cm−3) are achieved. Moreover, the fiber-based supercapacitor exhibits a high energy density of 8.8 mWh cm−3 at the power density of 49.2 mW cm−3 and a highpower density of 429.3 mW cm−3 at the energy density of 4.1 mWh cm−3, which is better than most previously reported graphene fiber-based supercapacitors. In these devices, we realize a desirable combination of excellent electrochemical performance and good flexibility, which will be significant for satisfying the requirement of the energy and power in various portable, miniaturized, and wearable electronic devices. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers were prepared from bacterial synthesis (bottom up approach) and electrospinning technique (top down method). Significant differences are noticed between bacterial (BC) and electrospun cellulose nanofibers (EC) in their properties such as diameter of fibers, decomposition temperature, surface area and mechanical strength. Filtration of cadmium oxide micro-particles and Staphylococcus aureus bio-aerosol using BC and EC was prominently influenced by their properties. Furthermore, in-vitro release of sparingly water soluble drug, ibuprofen was carried out using BC and EC as carrier materials. [ABSTRACT FROM AUTHOR]

Bacterial cellulose nanofibers (BCNF), obtained by the mechanical disintegration of BC pellicles, were used without any surface treatment for the fabrication of poly(lactic acid) (PLA) nanocomposites by a melt compounding process. The addition of BCNF in different amounts improved both the Young’s modulus and tensile strength of PLA. A 22% increase in these properties was observed in the nanocomposite with 2 wt.% nanofibers, due to the BCNF network formed at this concentration and characterized by atomic force microscopy. BCNF addition also increased the crystallinity and thermal stability of PLA, which were evaluated by thermal analysis. Due to the high purity of BCNF and the environmental friendliness of melt processing, it was concluded that PLA/BCNF nanocomposites can be designed for biomedical field and food packaging.

Although dissolving microneedles have garnered considerable attention as transdermal delivery tools, insufficient drug loading remains a challenge owing to their small dimension. Herein, we report a one-step process of synthesizing semi-dissolving microneedle (SDMN) patches that enable effective transdermal drug delivery without loading drugs themselves by introducing TEMPO-oxidized bacterial cellulose nanofibers (TOBCNs), which are well dispersed, while retaining their unique properties in the aqueous phase. The SDMN patch fabricated by the micro-molding of a TOBCN/hydrophilic biopolymer mixture had a two-layer structure comprising a water-soluble needle layer and a TOBCN-containing insoluble backing layer. Moreover, the SDMN patch, which had a hole in the backing layer where TOBCNs are distributed uniformly, could offer novel advantages for the delivery of large quantities of active ingredients. In vitro permeation analysis confirmed that TOBCNs with high water absorption capacity could serve as drug reservoirs. Upon SDMN insertion and the application of drug aqueous solution through the drug inlet hole, the TOBCNs rapidly absorbed the solution and supplied it to the needle layer. Simultaneously, the needle layer dissolved in body fluids and the drug solution to form micro-channels, which enabled the delivery of larger quantities of drugs to the skin compared to that enabled by solution application alone.

Abstract In this study, we have reported a novel fabrication technique for human serum albumin (HSA) imprinted composite bacterial cellulose nanofibers (MIP-cBCNFs) used for the depletion of HSA selectively from artificial blood plasma for proteomic applications. Molecular imprinting was achieved by using metal ion coordination interactions of N ‑methacryloyl‑(l)‑histidinemethylester (MAH) monomer and Cu(II) ions. MAH-Cu(II)-HSA complex was polymerized with bacterial cellulose nanofibers (BCNFs) under constant stirring at room temperature. The characterization of the MIP-cBCNFs was carried out by FTIR-ATR, SEM, contact angle measurements and surface area measurements. The adsorption experiments of HSA onto the MIP-BCNFs and NIP-BCNFs from aqueous HSA solutions were investigated in a batch system. The selectivity of the MIP-cBCNFs was investigated by using non-template human transferrin (HTR), and myoglobin (Myo). The relative selectivity coefficients of the MIP-cBCNFs were calculated as 4.73 and 3.02 for HSA/HTR and HSA/Myo molecules, respectively. In addition, the depletion of HSA from artificial human plasma was confirmed by SDS-PAGE and 2-D gel electrophoresis. As a result, it has been shown that metal ion coordination interactions contribute to specific binding of template when preparing MIP-cBCNFs for the depletion of HSA with a high adsorption capacity, significant selectivity and reusability. [ABSTRACT FROM AUTHOR]

Bacterial cellulose nanofibers (BCNF) were employed in order to improve various properties of fish myofibrillar protein (FMP) films of Silver carp. Three different levels (2, 4 and 6%, w/w) of the nanoparticles were added to the protein polymer substrate. In this regard, it became clear that 6% BCNF-containing nanocomposites had the highest tensile strength, which was about 49% better than control samples. The nanoparticles had positive impact on the physical properties; BCNF-containing films showed a reduction in water vapor permeability, swelling and solubility indexes. The results of SEM displayed uniform distribution and continuous cross-section of nanocomposite films. FTIR analysis of different films showed molecular interactions between nanoparticles and polymer substrate. XRD analysis represents the appearance of new peaks in polymer nanocomposites and the increase in crystallization of these films compared to the control film. Evaluation of thermal properties of these films suggests the improved thermal stability of the nanocomposites. [ABSTRACT FROM AUTHOR]

Fiber-based hybrid electrodes composed of carbon nanotube (CNT) and pseudocapacitance materials have gained great attention for wearable energy storage devices. However, it is still a challenge to obtain high capacitance fiber-based supercapacitor (FSC) with structurally optimized hybrid electrode. Herein, a flexible FSC with hierarchical core-sheath and porous structure is elaborately designed by self-assembly of multiple nanoscale polypyrrole@CNT/bacterial cellulose electrodes. The bacterial cellulose (BC) in the FSC not only efficiently prevent the aggregation of CNTs and significantly improve the wettability of supercapacitor, but also act as electrolyte nano-reservoirs, which can accelerate the diffusion of electrolyte ions and improve the electrochemical performance. The inner hierarchical core-sheath and porous structures significantly increase the specific surface area of the electrode and facilitate the ion transport resulting in considerably enhanced electrochemical properties. The assembled all-solid-state FSC exhibits high energy density of 6.8 mWh/cm 3 (8.3 Wh/kg) at power density of 38.6 mW/cm 3 (47.3 W/kg), power density of 391.7 mW/cm 3 (454.5 W/kg) at energy density of 3.6 mWh/cm 3 (4.2 Wh/kg), excellent cycling retention ability and bending ability. This high-performance FSC with well-designed structure fabricated by industrially viable wet-spinning technology, possessing great potential as the energy and power in various portable, miniaturized, and wearable electronic devices. [ABSTRACT FROM AUTHOR]

Bacterial cellulose is a biological macromolecule synthesized by bacteria of high purity and crystallinity. Bacterial cellulose nanofibers (BCNF) have been produced by soft homogenization and added to a recycled pulp to improve its quality. The benefits of BCNF on mechanical, physical and optical paper properties have been quantified and the retention mechanism of the BCNF in the paper network has been proposed. The use of BC to improve paper strength is usually limited by the decrease of tear index. The novelty of this work is that these two effects are decoupled by the addition of BCNF of low fibrillation (35.2%). In this way, some BCNF clusters are produced together with the individual nanofibers. Thus, with the addition of 3% BCNF, tensile and tear indexes as well as strain at break were improved by 11.1, 7.6, and 66.8%, respectively. Furthermore, the clusters were retained in the fiber network not only by hydrogen bonding, but also by physical retention within the gaps. Therefore, the addition of BCNF not only increases the mechanical properties of paper but also makes the handsheets more flexible and facilitates filler retention. [ABSTRACT FROM AUTHOR]

Here, we developed the lysozyme imprinted bacterial cellulose (Lyz-MIP/BC) nanofibers via the surface imprinting strategy that was designed to recognize lysozyme. This study includes the molecular imprinting method onto the surface of bacterial cellulose nanofibers in the presence of lysozyme by metal ion coordination, as well as further characterizations methods FTIR, SEM and contact angle measurements. The maximum lysozyme adsorption capacity of Lyz-MIP/BC nanofibers was found to be 71 mg/g. The Lyz-MIP/BC nanofibers showed high selectivity for lysozyme towards bovine serum albumin and cytochrome c. Overall, the Lyz-MIP/BC nanofibers hold great potential for lysozyme recognition due to the high binding capacity, significant selectivity and excellent reusability. [ABSTRACT FROM AUTHOR]

There is a significant need for the development of the novel adsorbents in the field of protein purification. In this study, thin hemoglobin imprinted film (MIP) was fabricated onto the bacterial cellulose nanofibers’ (BCNFs) by surface imprinting method using metal ion coordination interactions with N-methacryloyl–(L)-histidinemethylester (MAH) and copper ions. The hemoglobin surface imprinted bacterial cellulose nanofibers (MIP-BCNFs) was applied to selective recognition of hemoglobin and purification from hemolysate. The characterization of the MIP-BCNFs was carried out by the Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), micro-Computerized Tomography (μCT), atomic force microscopy (AFM) and surface area measurements. The adsorption experiments of hemoglobin onto the MIP-BCNFs and NIP-BCNFs from aqueous hemoglobin solutions were investigated in a batch system. The results showed that MIP-BCNFs are promising materials for purification of hemoglobin with high adsorption capacity, significant selectivity and reusability. [ABSTRACT FROM AUTHOR]

The potential of the modified bacterial cellulose (BC) nanofibers was determined bearing metal ion coordination interactions to enhance the protein adsorption and binding capacity. Thus, a household synthesized metal chelating monomer, namely N-methacryloyl- l -histidine methylester (MAH), and a commercial metal chelating monomer, namely 4-vinylimidazole (VIm), were used to complex with metal ions Cu(II) and Ni(II) respectively for the synthesis of the modified BC nanofibers. The modified nanofibers were characterized by FT-IR, SEM and EDX measurements. The protein adsorption tests were carried out using hemoglobin as a model protein and it was determined that the maximum adsorption capacity of hemoglobin onto the modified BC nanofibers was found as 47.40 mg/g. The novel strategy for the preparation of metal chelated nanofibers was developed. [ABSTRACT FROM AUTHOR]

A novel nanohybrid was successfully fabricated by deposition of gold nanoparticles (AuNPs) onto the surface of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized bacterial cellulose nanofibers (TOBCNs). The prepared AuNPs/TOBCNs nanohybrids were characterized by UV–vis spectral analysis, XRD, TEM and HRTEM. Their catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was estimated by UV–vis spectrometry. The results showed that the AuNPs/TOBCNs nanohybrids possessed AuNPs with an average diameter of 4.30 ± 0.97 nm exhibited superior catalytic properties for the reduction of 4-NP to 4-AP. The influences of the content of reducing agent and system temperature on the catalytic property were studied. Moreover, the turnover frequency of AuNPs/TOBCNs was 750 h −1 , which is higher than most recently reported AuNPs-based catalysts. This work reported a heterogeneous catalyst based on TOBCNs supported AuNPs with superior catalytic properties. [ABSTRACT FROM AUTHOR]

Bacterial cellulose nanofibers (BCNF), obtained by the mechanical disintegration of BC pellicles, were used without any surface treatment for the fabrication of poly(lactic acid) (PLA) nanocomposites by a melt compounding process. The addition of BCNF in different amounts improved both the Young's modulus and tensile strength of PLA. A 22% increase in these properties was observed in the nanocomposite with 2 wt.% nanofibers, due to the BCNF network formed at this concentration and characterized by atomic force microscopy. BCNF addition also increased the crystallinity and thermal stability of PLA, which were evaluated by thermal analysis. Due to the high purity of BCNF and the environmental friendliness of melt processing, it was concluded that PLA/BCNF nanocomposites can be designed for biomedical field and food packaging. [ABSTRACT FROM AUTHOR]

This research focuses on preparing a natural-based drug delivery system for α-arbutin (AR) as a skin lightening. Bacterial cellulose nanofibers (BC) pad was used for controlled-AR release through two approaches. First was the dip-drying method (P-BC), in which AR cross-linked to BC pads using citric acid (CA). The second was simultaneously entrapping of AR in Tragacanth gum (AR-TG) and stabilized on BC (BC-T) through the ultrasonic-assisted microemulsion method. UV–Vis spectra revealed better control of AR release in BC-T in the first hour. High cell viability (above 70 %) of the pads containing 1–3 % AR was reported using MTT assay. The in-vitro permeation study indicated the proper AR penetration in the treated pads. The Fickian diffusion model was determined as a fitted model for all pads in the drug release kinetics. FTIR, XRD, and TGA analyses further characterized the pads. FESEM images verified AR-TG and BC structures with average diameters of 410.7 ± 25.4 and 34.5 ± 7.51 nm, respectively. The hydrophilicity and mechanical properties of the pads were also investigated. Finally, the high biocompatibility, initial controlled release, and proper permeation suggested BC-T as a more promising delivery platform for AR. [Display omitted] • The potentiality of bacterial cellulose for alpha-arbutin delivery • Comparing alpha-arbutin release using dip-dry and microemulsion methods • Studying of kinetics of drug release from bacterial cellulose pad • Convenient skin pads for treating hyperpigmentation disorder • Producing considerable cell viability with controlled drug release [ABSTRACT FROM AUTHOR]

[Display omitted] • Oil-in-water emulsions were prepared using Lycium barbarum seed oil. • Green and environmentally friendly bacterial cellulose nanofibers and gelatin were used as tabilizers. • The effect of stabilizer concentration on the emulsion stability was investigated. • The antioxidant properties of the oil and its emulsions were evaluated. • The problem affecting the application of Lycium barbarum seed oil was solved. Lycium barbarum seed oil contains a variety of unsaturated fatty acids and other active substances, which is very beneficial to people's health. However, the application of Lycium barbarum seed oil is limited because it is insoluble in water and needs to be stored away from light. To solve these problems, Pickering emulsions were prepared by combining bacterial cellulose nanofibers and edible gelatin to stabilize Lycium barbarum seed oil. The average particle size, microstructure and rheology of the emulsion were characterized, and it was found that the droplets of the emulsion were smooth and distributed to the nanometer level, and the lowest concentration of bacterial cellulose nanofibers which could stabilize the emulsion was 0.3% (w/v). Surprisingly, by comparing the scavenging abilities of the Lycium barbarum seed oil and the emulsion on same free radicals, we observed that the antioxidant capacity of the emulsion increased significantly. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers possessing synthetic recognition sites present great potential for various application areas, which require specific recognition of molecules. However various molecularly imprinted polymers (MIPs) reported previously have low affinity capacity and low binding kinetics due to weak interactions between template molecule and functional monomer in aqueous media and also high mass transfer resistance. The synthesis of MIPs onto nanomaterial surface via metal ion coordination interactions serves as an effective solution. In this work, we prepared thin molecularly imprinted polymer layer on bacterial cellulose nanofiber surface using Cu 2+ chelating monomer, N -Methacryloyl-(L)-histidinemethylester (MAH) as a functional monomer orienting cytochrome c molecules. The conditions of polymerization and adsorption were optimized to obtain best affinity performance. Due to unique properties of bacterial cellulose nanofibers such as high surface-to-volume ratio and macro-porosity, the resultant cytochrome c imprinted nanofibers (Cyt c-MIP NFs) reducing diffusional resistances could achieve high recognition capacity and excellent binding kinetics. Cyt c-MIP NFs were also successfully applied to capture template proteins from real sample. This novel procedure presents simple, cheap and stable fabrication strategy for efficient separation of proteins. [ABSTRACT FROM AUTHOR]

Soft-tissue replacements are challenging due to the stringent compliance requirements for the implanted materials in terms of biocompatibility, durability, high wear resistance, low friction, and water content. Acrylate hydrogels are worth considering as soft tissue implants as they can be photocurable and sustain customized shapes through 3D bioprinting. However, acrylate-based hydrogels present weak mechanical properties and significant dimensional changes when immersed in liquids. To address these obstacles, we fabricated double network (DN) hydrogels composed of polyacrylic acid (PAA) and bacterial cellulose nanofibers (BCNFs) by one fast UV photopolymerization step. BCNFs/PAA hydrogels with a 0.5 wt% BCNFs content present an increased stiffness and a lower, non-pH-dependent swelling than PAA hydrogels or PAA hydrogels with cellulose nanocrystals. Besides, BCNFs/PAA hydrogels are biocompatible and can be frozen/thawed. Those characteristics endorse these hybrid hydrogels as potential candidates for vascular and cartilage tissue implants. [Display omitted] • Photocurable biocompatible double network (DN) hybrid hydrogels in a single step • Polyacrylic acid (PAA)/bacterial cellulose nanofibers (BCNFs) DN hydrogels are stiff but flexible. • The DN hydrogels swell less when immersed in water than PAA hydrogels. • PAA hydrogels with cellulose nanocrystals do not form a DN system. • PAA/BCNFs hydrogels are potential candidates for vascular or cartilage soft-implants. [ABSTRACT FROM AUTHOR]

New nanocomposites based on bacterial cellulose nanofibers (BCN) and polyurethane (PU) prepolymer were prepared and characterized by SEM, FT-IR, XRD, and TG/DTG analyses. An improvement of the interface reaction between the BCN and the PU prepolymer was obtained by a solvent exchange process. FT-IR results showed the main urethane band at 2,270 cm to PU prepolymer; however, in nanocomposites new bands appear as disubstituted urea at 1,650 and 1,550 cm. In addition, the observed decrease in the intensity of the hydroxyl band (3,500 cm) suggests an interaction between BCN hydroxyls and NCO-free groups. The nanocomposites presented a non-crystalline character, significant thermal stability (up to 230 °C) and low water absorption when compared to pristine BCN. [ABSTRACT FROM AUTHOR]

Herein, we propose a cellulose-reinforced hybrid hydrogel system that not only increases mechanical strength, but also allows on-demand drug release. This hybrid hydrogel is specialized by its semi-interpenetrating network structure in which bacterial cellulose nanofibers (BCNFs) penetrate through a polyacrylamide (PAM) mesh. We showed that the interpenetrating BCNFs with a higher aspect ratio of 240 increased the compression strength of PAM/BCNF composite hydrogels approximately 3-fold, compared with that prepared with PAM only, stemming from the reinforcing effect of the rigid natural nanofibers between PAM meshes. We also observed that the swelling kinetics depended on the mechanical properties determined by the BCNF aspect ratio. From further studies on drug release, we demonstrated that the tailored composition of BCNFs with PAM retarded drug release by a factor of two compared to PAM only while enabling on-demand drug release in response to the applied compressive stress. These results highlight that our BCNFs-reinforced hydrogel system can be applied as a mechanical stress-responsive smart drug delivery patch. • A bacterial cellulose nanofibril (BCNF)-reinforced hydrogel system is reported. • Mechanical properties of composite hydrogels are tuned by the aspect ratio of BCNFs. • Our composite hydrogels show on-demand drug release in response to compressive stress. [ABSTRACT FROM AUTHOR]