Green synthesis of silver nanoparticles with grape seed extract and blue laser activation for in vivo anti-Staphylococcus aureus activity in mice.

Abstract

Background and aim: Wound healing is a complex biological process often hindered by bacterial infections, particularly Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA). Conventional antibiotic treatments face challenges due to antimicrobial resistance, necessitating alternative approaches. This study evaluates the efficacy of blue laser-activated silver nanoparticles synthesized from grape seed extract (GSE-AgNPs) in promoting wound healing and reducing bacterial load in Wistar mice.

Materials and methods: GSE-AgNPs were synthesized and characterized before application. Wistar mice were divided into three experimental groups: (1) blue laser therapy alone, (2) GSE-AgNPs alone, and (3) combined treatment. A 2.5 cm incision was created on the dorsal side of each mouse, and treatments were administered on days 1, 3, and 5 post-incision. Wound healing progression was assessed through histopathology, bacterial colony counts, and immune response markers (lymphocyte and monocyte levels). Statistical analysis was performed using two-way analysis of variance, followed by Tukey's post hoc test.

Results: Compared with individual treatments, the combination of GSE-AgNPs and blue laser therapy significantly improved wound healing outcomes. The combined therapy led to a 60% reduction in wound size and an 88.73% decrease in S. aureus bacterial load. Immune response markers showed enhanced activity, with lymphocyte levels increasing by 75% and monocyte levels rising by 50%, indicating a stronger immune response. Histopathological analysis confirmed accelerated re-epithelialization and increased fibroblast activity in the combination therapy group.

Conclusion: The findings suggest that blue laser-activated GSE-AgNPs provide a promising alternative for enhancing wound healing and bacterial infection control, particularly against MRSA. The synergistic effect of nanoparticles and laser activation promotes immune modulation and tissue regeneration. Future research should explore clinical applications and dosage optimization for human use.