Programmable antimicrobial graphene oxide-silver nanoparticle-poly(acrylic acid) hydrogels for smart regenerative medicine

Abstract

Hydrogels with tunable physicochemical properties are being increasingly explored for advanced biomedical applications. In this study, two composite hydrogels were rapidly fabricated through the free radical polymerization of acrylic acid (AA) with the in situ formation of silver nanoparticles (AgNPs) in the presence and absence of graphene oxide (GO). The resulting GO-AgNP-poly(acrylic acid) and AgNP-poly(acrylic acid) hydrogels have been systematically characterized by functional group analysis, crystallinity, thermal stability, elemental analysis, and morphological studies using attenuated total reflectance-infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, energy dispersive spectroscopy, and field-effect scanning electronic microscopy, respectively. Both hydrogels demonstrated pH-switchable swelling–deswelling (on/off) behavior; however, the incorporation of GO provided interfacial channels that enhanced solvent interaction. The in situ-formed AgNPs (∼13 nm) endowed the hydrogels with strong antibacterial and anti-biofilm activity against both Gram-positive and Gram-negative bacterial strains. Cytotoxicity studies confirmed excellent biocompatibility with Vero, HeLa, and BHK-21 cell lines. The synergistic combination of pH-responsiveness, broad-spectrum antimicrobial activity, and cytocompatibility positions these novel composite hydrogels as promising candidates for smart wound healing and tissue engineering applications.