Integration of green synthesized silver nanoparticles in electrospun PVA-alginate and resveratrol-loaded ZIF-8 into alginate lyophilized hydrogel as a dual-layered biomimetic skin construct.

Cutaneous wound repair remains a critical biomedical challenge due to the skin's complex functional roles. This study introduces a dual-component biomaterial system that combines a polyvinyl alcohol-alginate (PVA-Alg) nanofibrous scaffold embedded with a green-synthesized silver nanoparticles (GsAg), combined with an alginate hydrogel loaded either ZIF-8 or resveratrol-loaded ZIF-8 (res@ZIF-8). The GsAg nanoparticles demonstrated potent antimicrobial and antifungal activities (0.5-32 μg/ml), while res@ZIF-8 hydrogels enhanced keratinocyte migration (76.98 ± 5.96 % of scratch gap closure) and increased fibroblast cell viability as confirmed by the MTT assay at concentrations of 32-128 μg/ml. Mechanically, the incorporation GsAg nanoparticles increased the yield strength and ultimate tensile strength (UTS) of the PVA-Alg-GsAg nanocomposite scaffold to 2.42 ± 0.42 and 4.26 ± 0.83 MPa, compared to 1.94 ± 0.15 and 2.70 ± 0.64 MPa for the scaffold without nanoparticles, respectively. Furthermore, the incorporation of ZIF-8 and res@ZIF-8 into Alg hydrogels reduced swelling ratios (after 24 h) to 188.8 ± 8.25 and 158.7 ± 15.25, and porosity to 59.75 ± 5.01 % and 58.87 ± 3.21 %, respectively, compared to 208.8 ± 12.38 and 63.07 ± 4.85 % for the pure Alg hydrogel. In contrast to controls, both ZIF-8 and res@ZIF-8 groups showed absent neutrophilic infiltration, with res@ZIF-8 further enhancing re-epithelialization confirmed by histological analysis after 21 days.