Self-enriched mesoporous silica nanoparticle composite membrane with remarkable photodynamic antimicrobial performances.

Mesoporous silica nanoparticle (MSN) demonstrates great potentials as a loading platform for bactericidal agents, but may be limited by its application form of bulk or powder. Herein, we developed MSN surface-enriched composite membranes with remarkable photodynamic antimicrobial activities via a facile electrospinning method. The mixture of zein and polycaprolactone (PCL) was served as the polymeric matrix, while the methylene blue (MB) loaded MSN was modified by trichloro (1H, 1H, 2H, 2H-heptadecafluorodecyl) silane (THFS) and acted as reactive oxygen species (ROS) generator to exert their antimicrobial performances. Owing to its low surface energy, the fluorinated MSN tended to be enriched on the surface of the nanofiber, hence significantly enhancing the ROS generation. Moreover, benefiting from the surface enrichment of the fluorinated nanoparticles, the composite membrane displayed obvious surface hydrophobicity and exhibited discernible bacterial repellency. Subsequently, upon visible light (660 nm) irradiation, the composite membrane demonstrated remarkable photodynamic antibacterial activities against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) but without essential detrimental impacts on the mammalian cells. We envision that this self-enriched MSN composite membrane may find broad applications in bacterial infection-resistant areas.