Functionalization of fibrous substrates with mesoporous silica nanoparticles as a strategy to obtain photodynamic antibacterial textiles

Abstract

The insertion of various nanomaterials and technologies in the search for antimicrobial textiles has grown in recent years, especially after the SARS-CoV-2 pandemic. Despite the efficiency, the design of a safe, scalable, low-cost, and robust antimicrobial textiles that cover all the spectra of microorganisms continues to be challenging. This gap can be filled using antimicrobial Photodynamic Therapy, a new promising approach that inactivates microorganisms in a very efficient way. In this contribution, we develop antibacterial textiles using photodynamic inactivation. To achieve that, we firstly synthesized amino functionalized mesoporous silica nanoparticles that were loaded with either Azure A or Rose Bengal. First the nanoparticles were characterized by X-ray Diffractometry, Transmission Electronic Microscopy, Thermogravimetric Analysis, N2 adsorption/desorption and dye loading. Further the nanoparticles (0.2 % w/w) were incorporated into cotton fabrics by exhaustion methodology. The antibacterial textiles were characterized by ATR-FTIR, Diffuse Reflectance, Fluorescence Microscopy, Scanning Electronic Microscopy, Fluorescence Lifetime, and singlet oxygen generation. The results showed that silica nanoparticles prevent the premature leakage of dyes from the fibers and retaining their photophysical properties, specifically their singlet oxygen production. The efficiency of antibacterial textiles was proven by the inactivation of Staphylococcus aureus and Escherichia coli. The developed materials showed antibacterial activity even in the dark, but enhanced in the light in some cases. Therefore, both systems have great potential as smart textiles for use in hospital clothing or wound dressings.