•Functionalized bacterial cellulose (BC) was obtained.•Functionalized BC exhibited excellent antibacterial activity.•Functionalized BC showed good biocompatibility.Bacterial cellulose (BC) membrane is a promising biopolymer which can be used for tissue implants, wound healing, and drug delivery due to its unique properties, such as high crystallinity, high mechanical strength, ultrafine fiber network structure, good water holding capacity and biocompatibility. However, BC does not intrinsically present antibacterial properties. In the present study, functionalized BC membranes were prepared. FTIR, SEM and XPS were used to characterize the chemical composition and surface morphology. Static water contact angles were measured to investigate surface wettability. Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida albicans were used to evaluate the antibacterial properties of membranes. HEK293 cell lines were applied to assess the biocompatibility of membrane surfaces by MTT assay and their morphologies were observed by Confocal Microscopy. Interestingly, the resultant functionalized BC membranes exhibiting excellent antibacterial property and good biocompatibility demonstrated great utility and potential as biomaterial materials.Download high-res image (279KB)Download full-size image

•Bacterial cellulose (BC)-graphene composite films were successfully prepared.•The addition of graphene decreased the hydrophilic property.•BC-graphene composites exhibited enhanced thermal stability.•The addition of graphene plays important roles in the mechanical improvements.Graphene has been considered to be a promising nanofiller material for building polymeric nanocomposites because it has large specific surface area and unique mechanical property. In the study, BC/graphene composites were prepared by a simple blending method. The resulting structure and thermal stability of the composites were investigated by several techniques including TEM, SEM, XRD, TG and Raman spectrum. These results indicate graphene nanosheets were successfully impregnated and uniformly dispersed in the BC matrix. Water contact angles result showed that the addition of graphene decreased hydrophilic property since water contact angle of BC increased from 51.2° to 84.3° with 4 wt% graphene added. The mechanical performances of BC/graphene composites were highly evaluated. When compared to pristine BC, the incorporation of 4 wt% graphene improved the tensile strength from 96 MPa to 155 MPa and Young's modulus from 369 MPa to 530 MPa, respectively.

•Tetracycline hydrochloride (TCH) was successfully loaded into bacterial cellulose (BC).•BC-TCH composite membranes displayed excellent antibacterial activities and no cytotoxicity in HEK293 cells.•The fabricated BC-TCH composite membranes can be used for wound dressing applications.Bacterial cellulose (BC) is widely used in biomedical applications. In this study, we prepared an antibiotic drug tetracycline hydrochloride (TCH)-loaded bacterial cellulose (BC) composite membranes, and evaluated the drug release, antibacterial activity and biocompatibility. The structure and morphology of the fabricated BC-TCH composite membranes were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The TCH release results show that the incorporation of BC matrix to load TCH is able to control the release. In vitro antibacterial assay demonstrate that the developed BC-TCH composites displayed excellent antibacterial activity solely associated with the loaded TCH drug. More importantly, the BC-TCH composite membranes display good biocompatibility. These characteristics of BC-TCH composite membranes indicate that they may successfully serve as wound dressings and other medical biomaterials.

Fabrication of cellulose based composites with controlled release and efficient antibacterial performances is of general interest in biomedical areas. In this study, antibiotic drug, tetracycline hydrochloride (TCH), loaded regenerated cellulose (RC) composite membranes were prepared and their drug release, antibacterial activity and biocompatibility were evaluated. The structure and morphology of the formed RC-TCH composite membranes were characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The TCH release results showed that the RC membrane is capable of controlled release. In vitro antibacterial assay demonstrated that the developed RC-TCH composites displayed excellent antibacterial activity, solely associated with the loaded TCH drug. More importantly, the RC-TCH composites displayed good biocompatibility, thus confirming its utility as potential in wound dressings and other medical applications.

A series of copper nanoparticle (CuNP) loaded regenerated bacterial cellulose (RC) membranes were fabricated. The prepared membranes were characterized in terms of their morphology and chemical composition. The results of SEM, EDS and elemental mapping indicated that CuNPs were successfully loaded into the RC matrix and RC–Cu membranes exhibited a homogeneous structure. XPS and XRD results showed copper is mainly present in the form of nanoparticles in the RC membranes. Antibacterial activity was evaluated against S. aureus ATCC 6538, B. subtilis ATCC 9372, C. albicans CMCC(F) 98001, E. coli ATCC 25922 and P. aeruginosa ATCC 27853 in vitro and RC–Cu membranes showed a significant antibacterial activity influenced by the CuNP content. Hence, RC–Cu membranes might have a great potential for use in the wound dressings and other biomedical areas.

Bacterial adhesion on the surfaces of medical devices, food processing equipment, heat exchangers and ship hulls has been recognized as a widespread problem. Bacterial adhesion on a surface is influenced by surface physical and chemical properties of the surface. In this paper, polyethyleneimine (PEI) grafted graphene oxide (GO) nanosheets were incorporated into Ni–P coatings by an electroless plating technique to modify the surface energy, and therefore to influence the interactions between the prepared surfaces and the tested bacteria. Ni–P–GO coatings were investigated by SEM, AFM, Raman spectrum and XPS. Contact angles of Ni–P–GO coatings with different GO loadings were tested and the surface free energies and their dispersive and polar components were calculated using the van Oss acid–base approach. The results showed that the surface free energies of the coatings had a significant influence on S. aureus adhesion. The Ni–P–GO coatings showed excellent antibacterial adhesion activity. Extended DLVO theory is used to explain the antibacterial adhesion behavior. The novel coatings reported here can be used in controlling bacterial adhesion and biofilm formation for various applications.

In this work, we report a facile and green approach to prepare a uniform silver nanoparticles (AgNPs) decorated graphene oxide (GO) nanocomposite (GO-Ag). The nanocomposite was fully characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, ultraviolet–visible (UV–vis) absorption spectra, and X-ray photoelectron spectroscopy (XPS), which demonstrated that AgNPs with a diameter of approximately 22 nm were uniformly and compactly deposited on GO. To investigate the silver ion release behaviors, HEPES buffers with different pH (5.5, 7, and 8.5) were selected and the mechanism of release actions was discussed in detail. The cytotoxicity of GO-Ag nanocomposite was also studied using HEK 293 cells. GO-Ag nanocomposite displayed good cytocompatibility. Furthermore, the antibacterial properties of GO-Ag nanocomposite were studied using Gram-negative E. coli ATCC 25922 and Gram-positive S. aureus ATCC 6538 by both the plate count method and disk diffusion method. The nanocomposite showed excellent antibacterial activity. These results demonstrated that GO-Ag nanocomposite, as a kind of antibacterial material, had a great promise for application in a wide range of biomedical applications.Keywords: antibacterial; cytotoxicity; graphene oxide; silver; silver release behavior

•Bacterial cellulose/sodium alginate (BC/SA)–AgSD composites were successfully prepared.•BC/SA–AgSD composites have pH-sensitive swelling behaviors.•BC/SA–AgSD composites exhibited excellent antibacterial activities.•BC/SA–AgSD composites showed good biocompatibility.•The prepared composites have great potential application in wound dressing areas.Sodium alginate (SA) and bacterial cellulose (BC) are widely used in many applications such as scaffolds and wound dressings due to its biocompatibility. Silver sulfadiazine (AgSD) is a topical antibacterial agents used as a topical cream on burns. In the study, novel BC/SA–AgSD composites were prepared and characterized by SEM, FTIR and TG analyses. These results indicate AgSD successfully impregnated into BC/SA matrix. The swelling behaviors in different pH were studied and the results showed pH-responsive swelling behaviors. The antibacterial performances of BC/SA–AgSD composites were evaluated with Escherichia coli, Staphylococcus aureus and Candida albicans. Moreover, the cytotoxicity of BC/SA–AgSD composites was performed on HEK 293 cells. The experimental results showed BC/SA–AgSD composites have excellent antibacterial activities and good biocompatibility, thus confirming its utility as potential wound dressings.

In the present work, a novel composite material formed by bacterial cellulose (BC) networks and graphene oxide (GO) nanosheets was synthesized by a sonochemical method. The BC and as-prepared BC/GO composites were characterized by several techniques including Scanning Electron Microscopy (SEM), Fourier-transform infrared (FTIR) spectra, ultraviolet-visible (UV-vis) absorption spectra, thermogravimetric analyses (TG) and X-ray diffraction (XRD). SEM images showed that the morphologies of composites became more compact than BC. FTIR, UV, TG and XRD confirmed the existence of GO in the composites. Moreover, HEK 293 cells were cultivated, and both the biocompatibility of the materials and the cell viability were demonstrated. Meanwhile, the anti-bacterial performances of BC/GO composites were evaluated with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which frequently cause medically associated infections. The experimental results showed that the BC/GO composites have excellent anti-bacterial activities, thus confirming its utility as a potential biomaterial in biomedical applications. Furthermore, the anti-bacterial behavior had been well explained by the extended DLVO theory.