Photothermal ablation of pathogenic bacteria by chensinin-1b modified gold nanoparticles

Abstract

Given the WHO report, resistance to antibacterial agents is responsible for the most deaths after car crashes every year. Thus, the development of new and more effective antibacterial classes is the main priority of the WHO. One of the most promising tools to tackle this problem is the designing and discovery of antibacterial peptides. Chensinin-1b is a modified analog of Chensinin-1, an antimicrobial peptide isolated from frog skin. The attachment of anti-bacterial peptides onto the surface of nanoparticles also enhanced their efficacy in synergistic manner.In this work, we functionalized the gold nanoparticles (GNPs) surface and evaluated the combinatorial effect of complex on the minimum inhibitory concentration (MIC) of the four pathogenic strains, including Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, in the presence and absence of laser irradiation. The physicochemical properties of naked and peptide modified gold nanoparticles were evaluated by Dynamic light scattering (DLS), Transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR) methods. Also, the MIC of GNP, peptides and their the complex were analyzed on bacterial strains before and after photo-thermal therapy (PTT).Our results showed that the peptide has a more significant inhibitory effect on the bacteria compared to GNPs. Also, we illustrated that the GNP/peptide complex has synergistic antimicrobial effects compared to free GNP and peptide. Furthermore, we confirmed that photo-thermal therapy augmented the inhibitory effect of GNP and chensinin-1b modified GNPs against some strains.This study showed that the chensinin-1b modified GNPs in the presence or absence of PTT strongly suppress pathogenic bacteria.