Characterization of Polyvinyl Alcohol/ZnO Nanocomposite Hydrogels for Wound Dressings

Polymeric hydrogels, as novel soft biomaterials, have found various applications in the medical field; for instance, as wound dressings and wound care management. In this study, in order to achieve wound dressings with improved properties, nanocomposite hydrogels using incorporation of nano zinc oxide (ZnO) in polyvinyl alcohol (PVA), were prepared by a freezing-thawing method. The effect of ZnO loading on the mechanical, structural, physical and antibacterial properties of the samples was investigated and the morphology of the prepared nanocomposite hydrogels was determined by field emission scanning electron microscopy (FESEM). The results of mechanical tests of the nanocomposite hydrogels, using compressive and hardness tests, indicated that by adding increasingly amounts of the ZnO nanoparticles, the mechanical properties of the nanocomposite hydrogels were improved. Structure-related properties of the hydrogels, such as swelling and gel fraction measurements, showed that the increase in ZnO content lead to a decrease in the swelling rate and increase in the gel fraction of the nanocomposites. Antibacterial and biocompatibility analysis revealed that, with increasing nano ZnO content, the antibacterial properties of the nanocomposite significantly increased and the cells viability rose, leading to slightly reduced toxicity. The results of this work indicated that the presence and quantity of added ZnO in the PVA hydrogels were very influential factors to obtain the desirable characteristics of wound dressings, such as absorbing the wound fluids and exudates, being biocompatible, anti-bacterial and nontoxic, and having mechanical stability and flexibility.