EGCG–GOLD METAL–PHENOLIC NANOPARTICLES FOR MILD PHOTOTHERMAL ANTIMICROBIAL AND ANTIBIOFILM THERAPY

The increasing prevalence of antimicrobial resistance and persistent biofilm-associated infections has created a need for alternative therapeutic strategies that can effectively eliminate microorganisms while minimizing damage to surrounding tissues. Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, possesses well-documented antimicrobial, antioxidant, and anti-biofilm properties; however, its therapeutic application can be limited by poor stability, bioavailability, and rapid degradation. The integration of EGCG with gold nanoparticles (AuNPs) provides a promising nanotechnology-based approach to overcome these limitations and enhance antimicrobial activity. EGCG can contribute to the synthesis and stabilization of gold nanoparticles while also providing inherent biological activity. Upon exposure to near-infrared or suitable light irradiation, gold nanoparticles can generate localized photothermal effects, producing mild heat that may disrupt microbial membranes, enhance oxidative stress, and weaken biofilm architecture. The combined action of EGCG-mediated antimicrobial activity and nanoparticle-assisted photothermal therapy may therefore provide a synergistic approach against both planktonic microorganisms and established biofilms. This strategy has potential applications in the management of difficult-to-treat bacterial infections and the development of localized antimicrobial therapies. Further studies are required to optimize nanoparticle size, EGCG loading, photothermal conditions, antimicrobial efficacy, biocompatibility, and long-term safety before clinical translation.