Multifunctional GO-Based Hydrogels with Various Inorganic Additives for Oral Health and Photodynamic Activation

In this study, we present the synthesis and characterization of graphene oxide (GO)-based hydrogels reinforced with hydroxyapatite (HA), titanium dioxide (TiO2), zinc oxide (ZnO), silicon oxide (SiO2), silver (Ag), and graphitic carbon nitride (g-C3N4). The aim is to develop multifunctional hydrogels with enhanced structural and biological performance and photocatalytic activity, opening the way for applications in regenerative medicine. The structure and composition of the hydrogels were investigated using FTIR and UV–Vis spectroscopy, which highlighted the chemical interactions between GO and the incorporated nanoparticles. The morphology was analyzed through scanning electron microscopy (SEM) and metallographic optical microscopy (MOM), confirming a uniform distribution of the inorganic phases and an internal architecture optimized for stability and bioactivity. Antibacterial activity was evaluated against Gram-positive and Gram-negative strains, both in the absence and presence of photodynamic therapy. The latter was activated by a Woodpecker laser at a 420 nm wavelength. The results showed significant bacterial inhibition, further enhanced by laser exposure, suggesting a synergistic effect between photocatalytic activation and the hydrogel components. Overall, the obtained hydrogels demonstrate robust mechano-structural properties and promising biological activity, supporting their potential for innovative biomedical applications in the tissue regeneration field and for the emerging biofunctional technologies.