Photosensitive antibacterial and cytotoxicity performances of a TiO2/carboxymethyl chitosan/poly(vinyl alcohol) nanocomposite hydrogel by in situ radiation construction

Nano-TiO2/carboxymethyl chitosan (CMCS)/poly(vinyl alcohol) (PVA) ternary nanocomposite hydrogels were prepared by freezing-thawing cycles and electron-beam radiation with PVA, CMCS, and nano-TiO2 as raw materials. The presence of nano-TiO2 nanoparticles in the composite hydrogels was confirmed by thermogravimetry, Fourier transform infrared spectroscopy, and Xray powder diffraction. Field emission scanning electron microscopy images also illustrated that the TiO2/CMCS/PVA hydrogel exhibited a porous and relatively regular three-dimensional network structure; at the same time, there was the presence of embedded nano-TiO2 throughout the hydrogel matrix. In addition, the nano-TiO2/CMCS/PVA composite hydrogels displayed significant antibacterial activity with Escherichia coli and Staphylococcus aureus as bacterial models. The antibacterial activity was demonstrated by the antibacterial circle method, plate count method, and cell density method. Also, with the Alamar Blue assay, the cytotoxicity of the composite hydrogel materials to L929 cells was studied. The results suggest that these materials had no obvious cytotoxicity. Thus, we may have developed a novel, good biocompatibility hydrogel with inherent photosensitive antibacterial activity with great potential for applications in the fields of cosmetics, medical dressings, and environmental protection. (C) 2016 Wiley Periodicals, Inc.