Eco-Friendly Fabrication of PVA/Chitosan Hydrogel With Superior Mechanical Strength and Antibacterial Efficacy

Green hydrogels hold promise for biomedical applications but are limited by weak mechanical properties. Here, we report a chitosan (CS)–reinforced polyvinyl alcohol hydrogel (PVA) fabricated via eco-friendly freeze–thaw cycles, achieving dual enhancement in mechanical strength and antibacterial efficacy. Incorporating 3 wt% chitosan increased compressive strength from 0.36 MPa in pure PVA to 2.92 MPa at 80% strain, while maintaining over 80% recovery after cyclic compression. The porous structure of the fabricated hydrogel and hydrogen-bonded network enabled sustained ciprofloxacin (CIP) release over 72 h. Antibacterial performance against Escherichia coli and Staphylococcus aureus improved significantly with CS addition, reaching 99% efficiency at 3% CS content, while CIP integration achieved complete bacterial eradication (100% efficiency). Synergistic action between the contact-based bactericidal activity of CS and CIP sustained release eliminated colony formation, demonstrating superior inhibition of both Gram-negative and Gram-positive bacteria. This green strategy delivers a mechanically robust, multifunctional hydrogel for infection-resistant biomedical applications.