Pristine Bacterial Cellulose Research Articles

Amidoximated Bacterial Cellulose Film for Pb2+ Adsorption in Aqueous Environment

Abstract This study investigated the application of amidoximated bacterial cellulose (AMO-BC) film for lead (Pb) adsorption from aqueous solutions. In our previous study, bacterial cellulose has been successfully modified through amidoximation to enhance its metal adsorption capacity. In order to modify the bacterial cellulose (BC) film, acrylonitrile was grafted onto it initiated by an electron beam to create BC-grafted-polyacrylonitrile (BC-g-PAN). After that, amidoximated bacterial cellulose (AMO-BC) was generated when BC-g-PAN reacted with hydroxylamine hydrochloride to add amidoxime functional groups to the cellulose backbone. Then, AMO-BC before and after lead adsorption was characterized using Fourier-transform infrared spectroscopy (FTIR). The adsorption capacity of AMO-BC for lead ions was evaluated through batch adsorption experiments with the initial lead concentration of 200 mgL−1 and an adsorbent dose of 20 mg, on pH 6 for two hours of the adsorption process. The results showed that AMO-BC exhibited higher lead adsorption capacity than pristine bacterial cellulose i.e., 44.56 and 50.96 mg/gram for BC and AMO-BC films, respectively.

Ex-situ fabrication of engineered green network of multifaceted bacterial cellulose film with enhanced antimicrobial properties for post-harvest preservation of table grapes

In order to overcome the inherent limitations of pristine bacterial cellulose (BC) as an active food packaging material, this study employs a dual-action approach to ex-situ fabricate a multifaceted green composite of BC through citrus pectin (CP) impregnation and subsequent functionalization with thyme essential oil (TEO) encapsulated CP-TEO active emulsion coating. Among various BC-CP composites studied, BC-CP1 revealed the optimal film formation with homogeneous dense microstructure, enhanced mechanical strength (from 126.37 MPa to 183.24 MPa), and reduced water vapor permeability (WVP) (from 3.69 ×10−11 g.m−1.s−1.Pa−1 to 3.33 ×10−11 g.m−1.s−1.Pa−1). The WVP was further reduced to 2.69 × 10−11 g.m−1.s−1.Pa−1 with the CP-TEO active emulsion coating. The BC-CP1/TEO2 exhibited exceptional antibacterial and antibiofilm characteristics, effective UV-blocking, and improved visible light transmittance. The film demonstrated superior potential in preserving grape quality over 9 days of storage compared to pristine BC and conventional plastic packaging. Thus, the BC-CP1/TEO2 has emerged as an eco-friendly, multi-layered solution for sustainable packaging needs.

Calcium crosslinked macroporous bacterial cellulose scaffolds with enhanced in situ mineralization and osteoinductivity for cranial bone regeneration

The inherent biological inertness and lack of three-dimensional (3D) macroporous structures greatly hinder the use of pristine bacterial cellulose (BC) as a tissue engineering scaffold for bone regeneration. To address this issue, we developed a simple and effective strategy to fabricate a BC-based scaffold with excellent bioactivity and macroporous structure by crosslinking short-cut BC nanofibers using Ca2+. The Ca2+ crosslinked macroporous BC scaffold (MPBC@Ca) presents better structural stability due to the enhanced cellulose hydration. Importantly, the Ca2+ on the surface of BC nanofibers can serve as an active nucleation site to accelerate the deposition of hydroxyapatite (HAp), which is beneficial for the construction of biomimetic bone tissue extracellular matrix (ECM) microenvironment. The HAp-deposited MPBC@Ca scaffolds (HAp-MPBC@Ca) with biomimetic ECM microenvironment have excellent cytocompatibility and enhanced osteogenic differentiation of stem cells in vitro. Furthermore, the results of in vivo tests revealed that the HAp-MPBC@Ca scaffold has favorable osteoinductivity and accelerates cranial bone tissue regeneration. This study proposes a novel strategy to improve the bioactivity of BC and presents the great potential of biomimetic ECM microenvironment BC-based scaffold for repairing large cranial bone defects.

Immobilization of UiO-66-NH2 into Bacterial Cellulose Aerogels for Efficient Particulate Matter Filtration

Metal–organic frameworks (MOFs) hold great potential for efficient removal of particulate matter (PM) due to their high porosity and tunable surface groups. In this work, sustainable bacterial cellulose (BC) was employed as a substrate for Zr-based MOF (i.e., UiO-66-NH2) deposition. Specifically, the UiO-66-NH2@BC aerogel exhibits a multi-level pore structure with a specific surface area of 103 m2/g. Pristine BC aerogels indicated a removal efficiency of 50.6% for PM2.5, with a pressure drop of 22.8 Pa. While UiO-66-NH2@BC aerogels showed a PM2.5 removal efficiency of 96.9%. The filtration mechanism can be assigned to the following reasons: (i) the interception/impaction of PM with the fibrous and porous aerogel network; and (ii) the presence of polar amine groups that boost electrostatic interactions between PM and MOFs. Moreover, as-prepared filters can be regenerated in a facile way with good reusability and long-term stability.

Carbon dots embedded bacterial cellulose membrane as active packaging: Toxicity, in vitro release and application in minced beef packaging

Antimicrobial bacterial cellulose (BC) membranes incorporated with carbon dots (CDs) were developed to improve the shelf life and ensure the safety of minced beef during 9 days of storage at 4 °C. An ex-situ method was used to develop BC-CDs with different CDs loading capacities (16.50, 22.50, and 38.50 mg/cm3). Only BC-CDs38.50 membrane exhibited toxicity in human embryonic kidney cells, and BC-CDs membranes had the slowest release rate of CDs in 95% ethanol. Significant differences were noted in the chemical and sensory attributes of samples packaged with BC-CDs16.50 and BC-CDs22.50, compared to the control. The microbial counts in samples with BC-CDs were significantly lower than those in samples with pristine BC membranes or the control. Notably, the BC-CDs22.50 membrane exhibited a substantial reduction (4.7 log10 CFU/g) in Escherichia coli counts by the end of storage. These findings highlight the potential of BC-CDs membranes as effective antimicrobial materials in meat packaging.

An Evaluation of the Usability of Argon Plasma-Treated Bacterial Cellulose as a Carrier for Controlled Releases of Glycoside Hydrolases PelAh and PslGh, Which Are Able to Eradicate Biofilm

Bacterial cellulose is a unique biopolymer that has found numerous biomedical applications, such as being an excellent wound-dressing material or a carrier for delivering active compounds. The purpose of this study was to analyze the ability of modified bacterial cellulose (BC) using low-pressure Ar plasma to control the release of glycoside hydrolases with antibiofilm activity, namely PelAh and PslGh, from Pseudomonas aeruginosa. The chemical composition and morphology of the BC surfaces were characterized using photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The analyses revealed significant changes in the chemical composition of the BC surface due to the introduction of charged functional groups and the conversion of its well-ordered structure into a more amorphous form. The release profiles of enzymes from both forms of the carrier were different and depended on their structural properties. However, a significant impact of BC modification on protein release behavior from the carrier was observed only for PslGh. Both enzymes, when immobilized on pristine and argon plasma-modified BC, retained their ability to effectively reduce biofilm levels, similarly to their soluble form. Ar plasma-modified BC with immobilized specific hydrolases can be used as an effective tool for inhibiting P. aeruginosa biofilm development.

Bacterial cellulose-based dressings with photothermal bactericidal activity and pro-angiogenic ability for infected wound healing

For most traditional wound dressings, it is challenging to simultaneously eliminate bacteria and promote angiogenesis to accelerate the healing process of bacteria-infected wounds. In this work, we develop a multifunctional dressing based on bacterial cellulose (BC) deposited with a tannic acid/Cu2+ ion/Mg2+ ion (TCM) complex film. Overall, the TCM complex exhibits robust interfacial adhesion to modify BC and good photothermal properties to effectively eradicate bacteria in the wound area under near-infrared (NIR) irradiation. The individual components of the TCM complex have several advantageous features for wound healing, such as antibacterial ability and negligible cytotoxicity; in particular, the released Cu2+ and Mg2+ ions are favorable for the proliferation, migration, and tube formation of endothelial cells in vitro. The results of in vivo experiments demonstrated that with the assistance of NIR irradiation, this composite dressing is more effective than traditional gauze or pristine BC dressing in promotion of angiogenesis and collagen deposition without causing remarkable inflammation, thereby accelerating the healing process of bacteria-infected full-thickness skin wounds. This work thus provides a simple and facile way to fabricate multifunctional BC-based dressings that could be potentially used for treating infected wounds.

Structural and morphological properties of in-situ biosynthesis of biocompatible bacterial cellulose/Laponite nanocomposites

Bacterial cellulose (BC) membranes were produced in culture media containing Komagataeibacter xylinus microorganism and four different concentrations of Laponite (Lap) XLG up to 1.0% (m/v) to evaluate the availability of in-situ method for production of BC/Lap nanocomposites. The effect of Lap on the structure and some properties of the biosynthesised polymer was evaluated by thermogravimetric analysis coupled to mass spectrometry (TGA-MS), Fourier Transform infrared (FT-IR) and Raman (FT-Raman) vibrational spectroscopies, X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM). TGA-MS and vibrational spectroscopy indicated that Lap particles were not incorporated into the BC membranes using 0.10 or 0.25% of the inorganic phase whereas all obtained results showed that its presence had a strong influence on the BC properties. This result can be an effect of the interaction of hydrophilic Lap particles with elementary fibrils of cellulose, expelled from the bacteria, fostering the disruption of chains organization. However, the 3D hierarchical organization of BC at the microscale was not collapsed according to SEM and AFM images. As the amount of Lap increased in the culture medium and in the produced membrane, the ribbons became less defined, suggesting the predominance of thinner ribbons. The transparency of the membranes was enhanced when the nanoclay loading was raised. The presence of high clay loadings in the BC/Lap nanocomposite did not negatively impact the cell viability against keratinocytes in comparison to pristine BC membranes, opening new opportunities to explore such nanocomposites for biomedical, pharmaceutical and cosmetics uses.

Development of low-cost bacterial cellulose-pomegranate peel extract-based antibacterial composite for potential biomedical applications

This study was aimed to develop low-cost bacterial cellulose (BC)-based antibacterial composite with pomegranate (Punica granatum L.) peel extract (PGPE) for potential biomedical applications. BC was cost-effectively produced by utilizing food wastes, and PGPE was ex situ impregnated into its hydrogel. Field-emission scanning electron microscopic (FE-SEM) observation showed a nanofibrous and microporous morphology of pristine BC and confirmed the development of BC-PGPE composite. Fourier transform infrared (FTIR) spectroscopy indicated the chemical interaction of PGPE with BC nanofibers. BC-PGPE composite held 97 % water of its dry weight and retained it for more than 48 h. The BC-PGPE composite exhibited better reswelling capabilities than pristine BC after three consecutive re-wetting cycles. The antibacterial activity of the BC-PGPE composite was determined via minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), disc diffusion, and plate count methods. The PGPE extract showed good antimicrobial activity against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), both in the form of extract and composite with BC, with relatively better activity against the former. The BC-PGPE composite produced a 17 mm zone of inhibition against S. aureus, while no inhibition zone was formed against E. coli. Furthermore, BC-PGPE composite caused a 100 % and 50 % reduction in the growth of S. aureus and E. coli, respectively. The findings of this study indicate that BC-PGPE composite could be a promising antibacterial wound dressing material.

Double-layered bacterial cellulose mesh for hernia repair

There is an unmet requirement for meshes with good anti-adhesion performance while maintaining favorable tissue integration. Herein, a double-layered bacterial cellulose (BC) mesh composed of pristine nanoporous BC layer and macroporous BC layer was prepared via the combined method of step-by-step in situ biosynthesis and particulate leaching. The mechanical properties of the novel mesh meet the requirements of hernia treatment. More importantly, the nanoporous BC layer shows efficient anti-adhesion performance while the macroporous layer exhibits excellent cell spreading and proliferation. This work provides a promising mesh to simultaneously meet the competing requirements of hernia repair.

Development of novel biocomposites based on the clean production of microbial cellulose from dairy waste (sour whey)

AbstractThis work explores the production of kombucha‐derived bacterial cellulose (KBC) from sour whey via the fermentation method using Komagatacibacter xylinus. The biosynthesis process was optimized by design of experiments and the results displayed highest KBC yield at 1000 ml/L sour whey waste, 87.39 g/L cane sugar, 6 g/L black tea, and 78.91 ml/L bacteria volume under 21 days culture period at 30°C. Optimum fermentation batch efficiency was achieved in large scale with cultured medium depths of 0.5 cm and low‐residual bacteria suspension volume of 72.31 ± 8.74 ml. The obtained KBC membranes were analyzed by SEM, FTIR, XRD, and TGA. The obtained results show no significant differences for all prepared KBC samples when compared to pristine bacterial cellulose from standard Hestrin and Schramm (HS) medium. In addition, the optimized KBC was investigated as a suitable bio‐filler in the preparation of biocomposite materials. The prepared biocomposites as leather alternative were further characterized and their mechanical tensile strength and elongation at break determined in the range of 135.61 ± 9.15 to 154.89 ± 9.09 N/mm2 and 31.06 ± 0.32 to 92.33 ± 6.91%, respectively. This model obtained depicts high‐yield production of KBC and its potential in the preparation of biocomposites.

TEMPO-oxidised nanocellulose hydrogels and self-standing films derived from bacterial cellulose nanopaper.

Hydrogels derived from TEMPO-oxidised cellulose nanofibrils (TOCNs) are not robust and inherently water unstable if the TOCNs are not crosslinked or coated with a water-swellable polymer. Furthermore, the manufacturing of self-standing TOCN films is still a challenge due to the small TOCN diameter and the viscosifying effect of TOCNs. Here, we report the TEMPO-mediated oxidation of bacterial cellulose (BC) nanopaper as a route to produce robust and water stable TOCN hydrogels without the need of additional additives or crosslinking steps. Pristine BC pellicle was first press-dried into a dried and well-consolidated BC nanopaper, followed by TEMPO-oxidation at various NaClO concentrations. The oxidation reaction introduced carboxylate moieties onto the exposed BC nanofibrils within the nanopaper network structure. This then led to the expansion and swelling of the nanopaper into a hydrogel. A swelling ratio of up to 100 times the original thickness of the BC nanopaper was observed upon TEMPO-oxidation. The water retention value of the TEMPO-oxidised BC hydrogels was also found to increase with increasing carboxylate content. These TEMPO-oxidised BC hydrogels were found to be robust and water-stable, even under prolonged (>1 month) magnetic stirring in water. We further showed that high grammage self-standing TOCN films (100 g m−2) can be fabricated as simple as press-drying these water stable TEMPO-oxidised BC hydrogels without the need of vacuum-assisted filtration or slow-drying, which is typically the rate-limiting step in the manufacturing of TOCN films.

Bacterial cellulose production from biodiesel–derived crude glycerol, magnetic functionalization, and its application as carrier for lipase immobilization

The present study aims towards the kinetic analysis of bacterial cellulose (BC) production by Gluconobacter xylinus from biodiesel–derived crude glycerol and its application as support for immobilization of lipase. Enhancement in strength of BC membrane and its magnetic functionalization were accomplished by the impregnation of iron oxide nanoparticles into the BC matrix. Fitting of experimental results to various substrate inhibition models revealed a reduction of substrate affinity (KS) and reaction rate (Vmax), and increase in substrate inhibition concentration of G. xylinus cells in presence of crude glycerol, in comparison to the pure form of glycerol. Improvement in mechanical properties of pristine BC and magnetic strength of functionalized BC membrane were confirmed by stress–strain curve and vibrating sample magnetometry analysis, respectively. This magnetic BC membrane provided suitable support for the immobilization of Candida rugosa lipase. The immobilized enzymes exhibited better activity at various temperatures, broader pH–flexibility, thermostability (retention of 48% of its activity after 180 min at 50 °C), and reusability (59% of its activity sustained after five consecutive runs). In comparison to free lipase, the immobilized lipase exhibited improved stability and activity, which could be applicable for industrial scale.

Enhancing piezoelectric properties of bacterial cellulose films by incorporation of MnFe2O4 nanoparticles

Low-cost and highly sensitive piezoelectric sensors were fabricated from bacterial cellulose (BC)/MnFe2O4 nanocomposite films via a co-precipitation method, followed by hot-pressing. MnFe2O4 nanoparticles were homogeneously distributed in the BC structure. The piezoelectric sensitivity measurements in the normal mode showed that the pristine BC film exhibited a sensitivity of ∼5 pC/N, whereas this value was increased to 23 pC/N for the composite film, which is comparable to the PVDF reference film. In the bending mode, the piezoelectric response increased to 25 pC/N and 57 pC/N for the BC film and the composite film, respectively. Moreover, the piezoelectric sensitivity was significantly enhanced using carbon tape electrodes attached directly to the films instead of sandwiched electrodes. This produced a sensitivity of greater than 50 pC/N for the MBC nanocomposite film in the normal mode measurement. Our work demonstrates the potential of using MBC composite films as inexpensive and highly sensitive flexible piezoelectric sensors.

Macroporous bacterial cellulose grafted by oligopeptides induces biomimetic mineralization via interfacial wettability

Bacterial cellulose (BC) has a role in tissue repair and regenerative medicine, which has already attracted tremendous interest from researchers, especially those working in the field of hybrid materials. Herein, we designed BC-based macroporous functional materials by dialdehyde bacterial cellulose (DBC) cross-linking with oligopeptides under mild reactive conditions. The interfacial properties of the surface modified BC were examined by biomimetic mineralization. The results showed that a macroporous structure was achieved by using oligopeptides as chemical cross-linking agents with an interconnected macroporosity ranging from 20 μm to 80 μm. Their mechanical properties were barely altered compared to the pristine BC. Their enhanced surface charges stemmed from the carboxyl groups of the oligopeptides engaging in reactions with amine and aldehyde groups. The oligopeptides cross-linked DBC showed a faster initial induction towards minerals via interfacial wettability resulting in promotion of mineralization, the hybrid materials had excellent biocompatibility relative to the pristine BC. These findings are vital to the development of other biopolymers with essential macroporous structures as well as improved interfacial wettability, which enables their possible uses in tissue repair and regenerative medicine.

Development, characterization and pre-clinical trials of an innovative wound healing dressing based on propolis (EPP-AF®)-containing self-microemulsifying formulation incorporated in biocellulose membranes

The considerable role of pristine bacterial cellulose membranes (BC) as ideal dressings have been widely demonstrated to treat wounds and burns. Nevertheless, drawbacks regarding antimicrobial spectrum and frequent dressing replacement are still present. Based on this, the present work proposes an innovative dressing by incorporating a technological self-microemulsifying formulation (SMEF) encapsulating propolis (BC/PP). BC/PP was fully chemically and biologically characterized employing in vitro and in vivo models. Antimicrobial studies demonstrated BC/PP high efficiency against both gran-negative and gran-positive bacteria. Release studies evidenced propolis markers sustained release for up to 7 days. In vivo wound healing activity was assessed by wound healing rate, anti-inflammatory and tissue formation events and the results evidenced the pro-inflammatory activity of BC/PP, which could promote improved healing results. To conclude, BC/PP presented an outstanding antibacterial activity in vitro with weekly replacement and promotion of healing, offering, for the first time, a broad-spectrum biomembrane potential to treat infected wounds.

Surface engineering of spongy bacterial cellulose via constructing crossed groove/column micropattern by low-energy CO2 laser photolithography toward scar-free wound healing

Bacterial cellulose (BC) is a bio-derived polymer, and it has been considered as an excellent candidate material for tissue engineering. In this study, a crossed groove/column micropattern was constructed on spongy, porous BC using low-energy CO2 laser photolithography. Applying the targeted immobilization of a tetrapeptide consisting of Arginine-Glycine-Aspartic acid-Serine (H-Arg-Gly-Asp-Ser-OH, RGDS) as a fibronectin onto the column platform surface, the resulting micropatterned BC (RGDS-MPBC) exhibited dual affinities to fibroblasts and collagen. Material characterization of RGDS-MPBC revealed that the micropattern was built by the column part with size of ~100 × 100 μm wide and ~100 μm deep, and the groove part with size of ~150 μm wide. Hydrating the MPBC did not result in the collapse of the integrity of the micropattern, suggesting its potential application in a highly hydrated wound environment. Cell culture assays revealed that the RGDS-MPBC exhibited an improved cytotoxicity to mouse fibroblasts L929, as compared to the pristine BC. Meanwhile, it was observed that the RGDS-MPBC was able to guide the ordered aggregation of human skin fibroblast (HSF) cells on the column platform surface, and no HSF cells were found in the groove channels. Over time, it was found that a dense network of collagen was gradually established across the groove channels. Furthermore, the in-vivo animal study preliminarily demonstrated the scar-free healing potential of the micropatterned BC materials. Therefore, this RGDS-MPBC material exhibited its advantages in guiding cell migration and collagen distribution, which could present a prospect in the establishment of “basket-woven” organization of collagen in normal skin tissue against the formation of dense, parallel aggregation of collagen fibers in scar tissue toward scar-free wound healing outcome.

EVALUATION OF BACTERIAL CELLULOSE-SODIUM ALGINATE FORWARD OSMOSIS MEMBRANE FOR WATER RECOVERY

Water resources are very important to sustain life. However, these resources have been subjected to stress due to population growth, economic and industrial growth, pollution and climate change. With these, the recovery of water from sources such as wastewater, dirty water, floodwater and seawater is a sustainable alternative. The potential of recovering water from these sources could be done by utilizing forward osmosis, a membrane process that exploits the natural osmotic pressure gradient between solutions which requires low energy operation. This study evaluated the potential of forward osmosis (FO) composite membranes fabricated from bacterial cellulose (BC) and modified with sodium alginate. The membranes were evaluated for water flux and salt rejection. The effect of alginate concentrations and impregnation temperatures were evaluated using 0.6 M sodium chloride solution as feed and 2 M glucose solution as the draw solution. The membranes were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Contact Angle Meter (CAM). The use of sodium alginate in BC membrane showed a thicker membrane (38.3 μm to 67.6 μm), denser structure (shown in the SEM images), and more hydrophilic (contact angle ranges from 28.39° to 32.97°) compared to the pristine BC membrane (thickness = 12.8 μm and contact angle = 66.13°). Furthermore, the alginate modification lowered the water flux of the BC membrane from 9.283 L/m2-h (LMH) to value ranging from 2.314 to 4.797 LMH but the improvement in salt rejection was prominent (up to 98.57%).

Hierarchically Porous Zirconia Monolith Fabricated from Bacterial Cellulose and Preceramic Polymer.

A hierarchically porous zirconia (ZrO2) monolith was successfully fabricated by using bacterial cellulose (BC) as a biotemplate and preceramic polymer as a zirconium resource, via freeze-drying and two-step calcination process. Images of scanning electron microscopy showed that the ZrO2 monolith well-replicated a three-dimensional reticulated structure of pristine BC and possessed good morphology stability till 1100 °C in air. Results of N2 adsorption/desorption and mercury porosimetry analysis revealed the hierarchically porous structure and large specific area (9.7 m2·g–1) of the ZrO2 monolith, respectively. Patterns of X-ray powder diffraction indicated that the monoclinic phase and tetragonal phase coexisted in the ZrO2 monolith with the former as the main phase. In addition, the ZrO2 monolith possessed low bulk density (0.13 g·cm–3) and good mechanical strength. These properties suggest that the as-prepared ZrO2 monolith has a great potential to serve as an ideal catalyst or catalyst support.

Cellulose-metallothionein matrix for metal binding

In this report, we have modified bacterial cellulose to a metal binding matrix by covalently conjugating physiological metal chelators known as metallothioneins. The hydroxyl groups of the native bacterial cellulose from Gluconobacter xylinus are epoxidized, followed by the covalent conjugation with the amine groups of the proteins. For the first time, a covalent conjugation of protein with bacterial cellulose is achieved using the epoxy-amine conjugation chemistry. Using this protocol, 50% mass by mass of the metallothionein could be attached to bacterial cellulose. The morphological features and porosity of the modified cellulose are different compared to pristine bacterial cellulose. Also, the conjugated material has better thermal stability. A five-fold enhancement in the metal binding capacity of the metallothionein conjugated bacterial cellulose is achieved as compared to pristine bacterial cellulose. Cellular metabolic assay and membrane integrity assay on MCF and HeLa cell lines showed no significant toxicity of the conjugate material. This bacterial cellulose-metallothionein conjugate can be explored for health care applications where management of metal toxicity is crucial. Further, the epoxy-amine chemistry for covalent conjugation of protein can be applied for several other types of proteins to develop specific functional biocompatible and biodegradable cellulose matrices.