Synthesis and characterization of chitosan and silver loaded chitosan nanoparticles for bioactive polyester

The paper focuses on the synthesis of chitosan nanoparticles (CSN) by ionic gelation with sodium tripolyphosphate and subsequently its loading with silver ions to produce silver loaded chitosan nanoparticles (Ag-CSN). The aim was to enhance the antibacterial property of chitosan in the nanoparticle form and thus improve its bactericidal efficacy when applied on polyester fabrics. The average particle size of CSN and Ag-CSN was 115 nm and 165 nm, respectively. The structure of CSN and Ag-CSN was studied by XRD, FTIR, DSC, TGA and TEM analysis. The minimum inhibitory concentration of both the CSN and Ag-CSN against Staphylococcus aureus bacteria was found to be 50 and 500 times less, respectively, as compared to bulk chitosan. Silver loading on the synthesized CSN showed synergistic antimicrobial effect against S. aureus bacteria. The release of Ag+ from Ag-CSN finished polyester fabric is substantiated by antibacterial testing which shows a clear zone of inhibition.