Cross-Linked Poly(acrylic acid) Hydrogel Loaded with Zinc Oxide Nanoparticles and Egg White Proteins for Antimicrobial Application

Abstract: In this study, poly(acrylic acid) hydrogels cross-linked with poly(ethylene glycol) diacrylate with different cross-linker content (5, 10 and 20%) were successfully prepared by UV photopolymerization. Hen egg white proteins were added to endow the hydrogel with appropriate rheological and antimicrobial properties. Mechanical properties of the hydrogels including swelling ratio, tensile strength and elongation at break were evaluated. Sample with 10% of the cross-linker showed the best mechanical characteristics among others, and was selected for the preparation of the target antimicrobial hydrogels. Zinc oxide nanoparticles (ZnO NPs) were prepared through hydrothermal method, functionalized with amine groups and added in three different amounts (0.1, 0.25 and 0.5 wt%) during preparation of the target hydrogels. The samples were fully characterized by Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffraction, and scanning electron microscopy. The zone of inhibition analysis revealed that the sample bearing 0.5 wt% of the ZnO NPs had the best antimicrobial effect. MTT assay showed all the samples were non-toxic against human dermal fibroblast (HSF-PI-16). The designed hydrogel could be considered as a promising antimicrobial film for further study in wound healing applications. Graphic Abstract: [Figure not available: see fulltext.].