Preparation and property of ZnO/sodium alginate bi-layered hydrogel films as novel wound dressings
Abstract: As one kind of natural materials, alginate has been widely investigated and used in biomedical field. Alginate-based hydrogels with the desired functional performance and good water-maintaining ability are helpful to promote the development of wound dressings. In this work, zinc oxide/sodium alginate (ZnO/SA) bi-layered hydrogel films were designed and prepared using ZnO and SA as the raw materials by a strategy combining the casting and solvent evaporation processes. The chemical structure and porous morphology of the prepared hydrogel films were determined by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry and field-emission scanning electron microscope. Furthermore, some properties of bi-layered hydrogel films were also evaluated regarding the wettability, water solubility, swelling ability, mechanical property, antibacterial property, in vitro cytotoxicity and in-vivo wound healing ability. The results suggest that the prepared ZnO/SA bi-layered hydrogel films have a high transparency, suitable hygroscopicity, good swelling and adequate mechanical strength. With improving the content of ZnO, the trend of antibacterial rate of ZnO/SA films increases gradually and the maximum antibacterial rate of 68.4% can be achieved when the content of ZnO is 0.04%. In addition, the ZnO/SA bi-layered hydrogel films have no significant cytotoxicity to L929 Fibroblasts cells through a MTT assay, and also possess the enhanced in-vivo wound healing ability, presenting the promising potential for applications as novel wound dressings.