Journal of Lasers in Medical Sciences

Abstract

Introduction: Silver nanoparticles (AgNPs) exhibit potent antimicrobial activity, and their combination with chitosan nanoparticles (CsNPs) may provide enhanced antibacterial effects. Although numerous eco-friendly approaches for AgNP synthesis have been reported, the use of green-synthesized AgNPs in combination with CsNPs for laser assisted antibacterial applications remains limited. This study aimed to develop a rapid microwave-assisted green synthesis of AgNPs using Myrmecodia pendans extract and to evaluate the antibacterial and photodynamic effects of AgNPs–CsNPs formulations.
Methods: AgNPs were synthesized using M. pendans extract as a natural reducing and stabilizing agent rich in polyphenolic compounds. Antibacterial activity was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa using bacterial growth assessment. Photodynamic inactivation was performed using a 405-nm blue laser with irradiation times of 90–180 s at different nanoparticle concentrations. Experiments were performed in five replicates, and data were expressed as mean±standard deviation. Statistical analysis was conducted using one-way ANOVA followed by Tukey’s post hoc test.
Results: UV-Vis spectroscopy showed characteristic absorption peaks at approximately 430 nm and 290 nm for AgNPs and CsNPs, respectively. Dynamic light scattering revealed particle sizes below 45 nm for AgNPs and approximately 11 nm for CsNPs. The combined AgNPs–CsNPs formulations demonstrated significantly greater antibacterial activity than M. pendans extract alone against both S. aureus and P. aeruginosa (P<0.05). Following 405-nm blue laser irradiation for 90–180 s, the AgNPs–CsNPs formulations produced near-complete bacterial reduction, particularly against P. aeruginosa, whereas non-irradiated treatments exhibited lower antibacterial activity.
Conclusion: Green-synthesized AgNPs produced using M. pendans extract can be effectively combined with CsNPs to enhance antibacterial activity. The combination of AgNPs–CsNPs with 405-nm blue laser irradiation showed enhanced photodynamic antibacterial performance, indicating its potential as a laser-assisted antimicrobial strategy against bacterial pathogens.