Fabrication and characterization of functionalized chitosan/TiO2 film composites with antimicrobial properties

Abstract

With the current rise in the need for novel materials with biomedical applications, nanotechnology has provided the framework for designing novel materials with both regenerative and antimicrobial characteristics. This work implemented a novel synthetic workflow to generate functionalized particulate and film composites. The materials were tested for an antimicrobial effect of the side group of a series of silane coupling agents when used to modify the surface of titanium dioxide particles and applied as filler in chitosan-starch films. These materials were analyzed for their water retention capacity, film moisture, mechanical properties, and antimicrobial capacity against Escherichia coli and Bacillus subtilis. The materials' physical, chemical, and viscoelastic properties were determined and showed they are suitable for tissue applications since they were elastic enough while maintaining a suitable water content and water absorption necessary in body physiology. In addition, the change in their mechanical and structural properties was analyzed once they were subjected to a photodegradative process. It was found that the rutile particles functionalized with 3-aminopropyltrimethoxysilane or imidazole showed antimicrobial activity against both bacteria, both alone and on chitosan-starch films. Also, the rutile amine particulate composite showed general cell damage in direct contact with a reporter E. coli strain, suggesting the release of ions that produce cell stress. The film composites showed mechanical properties suitable for tissue regeneration and, with the proper combination, antimicrobial activity. With the novel synthesis shown here, which is cost-effective and can be applied to other biomedical applications, novel materials can be generated for suitable biomedical applications.