# Eco-Friendly In Situ Fabrication of Silver Nanoparticle-Loaded Chitosan Nanogels for Antibacterial Applications

## TL;DR

Researchers created eco-friendly chitosan nanogels loaded with silver nanoparticles that show strong antibacterial properties and good biocompatibility.

## Contribution

The study introduces a green synthesis method for size-tunable silver nanoparticle-loaded chitosan nanogels with enhanced antibacterial and injectable properties.

## Key findings

- Silver nanoparticles of 3.72 nm were uniformly dispersed in chitosan nanogels using an 18:1 CSNG to AgNO3 mass ratio.
- The nanocomposites showed inhibition zones of 14.3 mm against E. coli and 12.1 mm against S. aureus.
- The nanocomposites exhibited cell viability exceeding 82.3% at 100 μg/mL, outperforming conventional silver formulations.

## Abstract

Eco-friendly chitosan nanogels (CSNG) with an average diameter of 48.5 nm were synthesized via alkali/urea dissolution and employed as templates for in situ silver nanoparticle fabrication. Silver nanoparticle size was controlled by adjusting CSNG to AgNO3 mass ratios, with the optimal ratio of 18:1 producing ultrasmall particles of 3.72 nm, uniformly dispersed in the matrix. The nanocomposites demonstrated superior antibacterial activity, with inhibition zones of 14.3 mm against E. coli and 12.1 mm against S. aureus, significantly exceeding pure CSNGs at 7.4 mm and 6.9 mm, respectively. Rheological analysis revealed shear-thinning behavior, with viscosity decreasing from 450 Pa·s to 0.1 Pa·s, confirming excellent injectability. Cytotoxicity evaluation showed cell viability exceeding 82.3% at 100 μg/mL, which was substantially superior to conventional silver formulations. Thermogravimetric analysis and FTIR spectroscopy verified enhanced thermal stability and coordination interactions between chitosan and silver species. This green synthesis approach yields injectable, size-tunable nanocomposites with combined antibacterial efficacy and biocompatibility for biomedical applications.