Zinc Oxide Nanoparticles Incorporated in Poly-Hydroxyethyl Methacrylate/Acrylamide Membrane Trigger the Key Events of Full-Thickness Wound Healing in a Rabbit Model

Zinc oxide nanoparticles are known to possess anti-inflammatory, antibacterial, and antiseptic properties and find wide application in the preparation of topical ointments. Wound dressings in the form of hydrogels can replenish the wound microenvironment to aid the healing process in a multidimensional way. We have fabricated a composite hydrogel using 1-3 wt. % ZnO nano-particles, synthesized by chelation reaction, and poly-2-hydroxyethyl methacrylate (pHEMA)/acrylamide, synthesized, and co-polymerized in 8 kGy gamma irradiation. Developed powders and composite membranes have been thoroughly analyzed for XRD, FTIR, SEM-EDX mapping, DTA/TGA, particle size, shape, morphology, porosity, water uptake, and contact angle. Thermally stable phase-pure ZnO spherical nanoparticles with an average crystallite size of 40 +/- 2 nm have been used for fabricating well-dispersed composite with contact angle varying 78o-88o. These membranes, when used in vivo, rendered a suitable environment conducive to tissue regeneration and ECM component deposition sequentially. Endowed with antibacterial properties, these hydrogels also demonstrated excelling swelling capacity which proved beneficial in maintaining a moist wound environment aiding in the healing process. An earlier wound closure was achieved with 2%-3% ZnO-pHEMA/acrylamide hydrogels which demonstrate the potential of ZnO nanoparticles in signaling and instructing the wound bed milieu towards the efficient repair.