Biodegradable polyhydroxybutyrate microfiber membranes decorated with photoactive Ag-TiO2 nanoparticles for enhanced antibacterial and anti-biofouling activities

Developing advanced materials with antibacterial and antifouling activities offers an adequate protection solution against surface bacterial contamination-a common cause of infection threatening human health. The current work reports the preparation of polyhydroxybutyrate (PHB) microfiber membranes decorated with photoactive Ag-TiO2 nanoparticles using electrospinning coupled with dip-coating methods. The decoration of Ag-TiO2 nanoparticles strongly enhances the antibacterial properties of prepared membranes, particularly under light illumination, thanks to their photocatalytic activity. The best-performing sample exhibits potent antibacterial efficiency exceeding 99% against Escherichia coli and Staphylococcus epidermidis after 3 and 1 h of exposure to low-power commercial LED light, respectively. The prepared samples also display excellent reusability with an insignificant antibacterial activity decrease after three cycles (<2% loss in antibacterial efficiency). Furthermore, these samples effectively prevent bacterial fouling due to their potent antibacterial properties. Notably, despite the strong antibacterial effect, decorated Ag-TiO2 nanoparticles promote the adhesion of microorganisms, accelerating the biodegradation of PHB microfibers. As a result, the prepared microfiber membranes with nanoparticle decoration exhibit biodegradability comparable to the non-decorated membrane, with the soil degradation rates reaching almost 99% after only 6 weeks.