High antibacterial in vitro performance of gold nanoparticles synthesized by epigallocatechin 3-gallate

In the present work, we report antibacterial activity of gold nanoparticles (AuNPs) prepared using Epigallocatechin 3-Gallate (EGCG) against S. aureus, E. faecalis, P. aeruginosa and E. coli. The synthesized AuNPs-EGCG showed optimal stability in physiological in vitro conditions and could be resuspended in various solvents. In vitro antibacterial activity against Gram-positive and Gram-negative bacteria was evidenced by inhibition of viable cell growth, with MIC values varying between 15 and 120 mu g mL(-1) in all treated bacteria. The antibacterial effects of the nanoformulation were the result of direct interaction with the surfaces of treated bacteria, causing morphological deformations that induced lysis and cell death. Besides, in vitro cytotoxicity analyses in murine fibroblast cells (L929) and human keratinocytes (HaCaT) showed high cell viability levels after 24 h of treatment with AuNPs-EGCG, with IC50 values of 267.55 e 293.04 mu g mL(-1), respectively. Thus, in its adsorbed form in gold nanoparticles, EGCG had its antibacterial activity potentiated and was less cytotoxic. AuNPs-EGCG shows high potential for future biomedical applications as an antibacterial treatment against skin infections.

Automated summary

The study demonstrated the antibacterial activity of AuNPs prepared using EGCG against various bacterial strains, both Gram-positive and Gram-negative. The nanoformulation interacted directly with bacterial surfaces, causing morphological deformations that induced lysis and cell death. In vitro cytotoxicity analysis showed high cell viability levels and potential for biomedical applications as an antibacterial treatment.