Biodegradable electrospun nanofiber membranes containing Ag-decorated TiO2 nanowires with antibacterial and UV-blocking properties

Abstract

Biodegradable cellulose acetate butyrate (CAB) nanofiber membranes containing Ag-decorated TiO<inf>2</inf> nanowires were fabricated via electrospinning. These nanofibers exhibited UV- blocking and antibacterial properties and can be used as skin contact products such as cosmetic patches and facial masks. TiO<inf>2</inf> is widely used as an inorganic UV-blocking agent in cosmetics. However, crystalline TiO<inf>2</inf> at the nanoscale can generate reactive oxygen species (ROS) and may penetrate into the compromised skin, raising safety concerns. Anatase TiO<inf>2</inf> exhibits much higher photocatalytic activity than rutile. Therefore, one-dimensional (1D) rutile-phase TiO<inf>2</inf> nanowires were selected and synthesized through electrospinning and calcination to reduce penetration risk and minimize ROS generation while maintaining high UV-blocking efficiency. Ag nanoparticles were deposited onto the TiO<inf>2</inf> surface using tannic acid, which served both as a reductant and a stabilizer. This could confer the light independent antibacterial activity. The CAB nanofibers containing Ag/TiO<inf>2</inf> exhibited an average fiber diameter of 715.35 nm and a membrane thickness of 31 μm, achieving a UV-blocking rate of 99.3% and a UPF value of 265 (50+). Antibacterial tests indicated no activity for CAB and TiO<inf>2</inf>–CAB nanofibers. In contrast, the Ag/TiO<inf>2</inf>–CAB nanofibers exhibited inhibition zones of 2 mm for E. coli and 3 mm for S. aureus which indicates effective antibacterial performances.