Multifunctional polyvinyl alcohol/graphene oxide hydrogels loaded with green tea extract: a bioactive platform for antioxidant, antibacterial, and accelerated wound healing

The integration of natural bioactive agents into nanocomposite hydrogels is a promising approach for advanced wound healing applications. In this study, multifunctional polyvinyl alcohol (PVA)-based hydrogels were developed via cyclic freeze–thawing, incorporating green tea extract (Ex) and graphene oxide (GO). GO served as a physical crosslinker, enhancing mechanical strength and structural stability of the hydrogel matrix. Among the developed formulations, PVA/Ex/GO 150 exhibited optimal performance, with superior swelling behavior, minimal degradation, and sustained Ex release (96.46% over 120 h). The mechanical analysis demonstrated a significant improvement in tensile strength (514.56 MPa) and elongation at break (387.36%), indicating enhanced flexibility and durability. The hydrogels displayed excellent biological performance, with cell viability exceeding 85% after 48 h, confirming good cytocompatibility. Hemocompatibility evaluation revealed low hemolysis rates (<10%) and improved blood clotting ability. Notably, the developed hydrogels exhibited strong antibacterial activity against S. aureus and E. coli , with inhibition zone diameters reaching 15.3 ± 0.5 mm and 11.1 ± 0.4 mm, respectively, for the PVA/Ex/GO (150 mg) formulation. Furthermore, antioxidant analysis using the DPPH assay showed a significant enhancement in radical scavenging activity, increasing from 3.64% (pure PVA) to 51.66% for PVA/Ex/GO (250 mg), highlighting the synergistic effect of GO and green tea polyphenols. Overall, the combined antibacterial, antioxidant, and biocompatible properties of the PVA/Ex/GO nanocomposite hydrogels, along with their controlled release behavior, make them promising candidates for advanced wound dressing and tissue regeneration applications.