Evaluation of Antimicrobial and Anti-Biofilm Formation Activities of Novel Poly(vinyl alcohol) Hydrogels Reinforced with Crosslinked Chitosan and Silver Nano-Particles

Novel hydrogels were prepared by blending chitosan and poly(vinyl alcohol), PVA, then crosslinking the resulting blends using trimellitic anhydride isothiocyanate at a concentration based on chitosan content in the blends. The weight ratios of chitosan: PVA in the blends were 1:3, 1:1, and 3:1 to produce three hydrogels symbolized as H(13), H(11), and H(31), respectively. For a comparison, H(10) was also prepared by crosslinking pure chitosan with trimellitic anhydride isothiocyanate. For further modification, three H(31)/silver nanocomposites (AgNPs) were synthesized using three different concentrations of silver nitrate to obtain H(31)/AgNPs1%, H(31)/AgNPs3% and H(31)/AgNPs5%. The structures of the prepared samples were emphasized using various analytical techniques. PVA has no inhibition activity against the tested microbes and biofilms. The antimicrobial and anti-biofilm formation activities of the investigated samples was arranged as: H(31)/AgNPs5% ≥ H(31)/AgNPs3% > H(31)/AgNPs1% > H(10) > H(31) > H(11) > H(13) > chitosan. H(31)/AgNPs5% and H(31)/AgNPs3% were more potent than Vancomycin and Amphotericin B against most of the tested microbes. Interestingly, H(31) and H(31)/AgNPs3% were safe on the normal human cells. Consequently, hydrogels resulting from crosslinked blends of chitosan and PVA loaded with AgNPs in the same structure have significantly reinforced the antimicrobial and inhibition activity against the biofilms of PVA.