Incorporation of Aloe vera and green synthesized ZnO nanoparticles into the chitosan/PVA nanocomposite hydrogel for wound dressing application

Nanocomposite hydrogels including chitosan (CS)/polyvinyl alcohol (PVA)/Aloe vera (AV)/zinc oxide nanoparticles (ZnO-NPs) were prepared as a wound dressing. The ZnO-NPs was synthesized using green synthesis method by Matricaria chamomilla leaf extract. The hydrogels were investigated using ultraviolet-visible (UV-Vis), Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy (SEM). In addition, other properties such as mechanical properties, swelling ratio, degradation rate, water vapor transmission rate, porosity percentage, cell viability, and antibacterial efficacy of the hydrogels were assessed. The release of synthesized ZnO-Nps from hydrogels was investigated. The results show that the addition of 5 wt.% Aloe vera to CS/PVA, water absorption, and WVTR increased by 276% and 68.98%, respectively. The maximum tensile strength and Young's modulus were found for the CS/PVA/AV/ZnO hydrogel containing 2 wt.% NPs, increasing by 150% and 28% over CS/PVA hydrogel, respectively. The SEM images revealed the agglomeration of NPs by increasing the ZnO-NPs content, reducing the ZnO-NPs release and skin absorption. Also, the degradation rate decreases by increasing the ZnO-NPs content from 0.5 to 2 wt.%. The cell viability studies showed no toxicity after loading of ZnO-NPs into the hydrogel and showed proper antibacterial activity against Staphylococcus aureus and Escherichia coli.