Preparation of composite membranes with high tensile strength and antibacterial properties based on Ag-nanoparticles deposition on bacterial cellulose/apocynum venetum

Abstract

Bacterial cellulose (BC), a natural nanofiber synthesized by bacteria, possesses a distinctive three-dimensional structure. Moreover, it exhibits superior properties like high water-holding capacity, high biocompatibility, non-toxicity, and biodegradability, conferring it with tremendous application potential in wound healing. Nevertheless, the lack of antibacterial property of BC restricts the use of pure BC membrane in the biomedical field. In this study, using BC as the substrate, it was compounded with Apocynum venetum (Av) to fabricate Bacterial cellulose-Apocynum venetum membrane (BC-Av). Subsequently, a nanosilver solution was prepared by reducing the AgNO₃ solution with ethylene glycol, and Ag was uniformly deposited on the surface of the BC-Av membrane via supercritical carbon dioxide (Sc-CO₂) fluid. The outcomes revealed that the Ag-loaded BC-Av membrane (BC-Av-Ag) exhibited excellent antibacterial efficacy against S. aureus and E. coli, reaching 99.8% and 99.5% respectively, along with superior mechanical properties such as higher tensile strength (1.65 ± 0.03 MPa), Young's modulus (6.5 ± 0.25 MPa), and fracture strain (32.5 ± 1.5%). Additionally, it was verified that this green composite material not only possesses high thermal stability but also enhances the hydrophilicity of BC. The combination of the biodegradability and biocompatibility of BC-Av and BC-Av-Ag membrane lays a foundation for their future application in medical protective materials.