Green Synthesis of Silver Nanoparticles using Cirsium congestum Extract Modified by Chitosan/Alginate: Bactericidal...

The study aimed to determine in vitro pharmacological effects of modified Ag nanoparticles (AgNPs).

AgNPs are considered antimicrobial agents. However, the cytotoxicity of chemically synthesized AgNPs (cAgNPs) has raised challenges that limit their use.

The purpose of the study was to examine the antimicrobial and cytotoxicity effects of AgNPs synthesized using Cirsium congestum extract modified by chitosan/alginate AgNPS (Ch/ALG-gAgNPs).

Nanoparticles were characterized using TEM, DLS, XRD, and FTIR. Resistant strains of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used for the antimicrobial analysis of Ch/ALG-gAgNPs using disc diffusion and microdilution methods. The effects of NPs on cell viability and apoptosis in L929 normal cells were determined using MTT assay and annexin/PI staining, respectively.

Physicochemical characterizations confirmed Ch/ALG-gAgNPs to be spherical and uniformly dispersed, and their size ranged from 50 to 500 nm. Ch/ALG-gAgNPs inhibited the growth of microbial strains in a dose-dependent manner. The antibacterial effect of Ch/ALG-gAgNPs was significantly higher than cAgNPs. The Ch/ALG-gAgNPs showed little cytotoxicity against normal cells at concentrations less than 50 μg/ml. Cytotoxicity effects of Ch/ALG-gAgNP were less than cAgNPs. Flow cytometry and real-time PCR results showed a decrease in apoptosis percentage and BAX marker in the presence of Ch/ALG-gAgNPs relative to when the cell was treated with cAgNPs.

Current findings introduce novel gAgNPs modified with chitosan/alginate for use in medicine.