# In Vitro Antimicrobial Evaluation of Silver Nanoparticles in Lyotropic Liquid Crystals for Cutaneous Wound Treatment

## TL;DR

This paper explores using silver nanoparticles in liquid crystal formulations to treat skin infections effectively and safely.

## Contribution

The study introduces lyotropic liquid crystals as a novel controlled-release platform for silver nanoparticles in wound treatment.

## Key findings

- LC-AgNP formulations showed efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.
- AgNPs were released between 1% and 70% over 24 hours, depending on formulation structure.
- LC formulations demonstrated biocompatibility with L-929 fibroblast cells.

## Abstract

Complex wounds, burns, and diabetic complications increase
patients’
susceptibility to bacterial infections, which frequently show resistance
to standard treatments. This investigation focused on evaluating the
antimicrobial potential of lyotropic liquid crystal (LC) formulations
loaded with silver nanoparticles (AgNPs) against Staphylococcus
aureus, Pseudomonas aeruginosa, and Escherichia coli strains. The
liquid crystals (LCs) were prepared by incorporating an oily phase
(PPG-5-CETETH-20 and oleic acid) into an aqueous phase containing
the AgNP nanosuspension. LC-AgNPs formulations, containing AgNPs concentrations
between 4.68 μg/mL and 14.04 μg/mL, were examined using
polarized light microscopy (PLM), which identified hexagonal, Maltese-cross/lamellar,
and dark-field mesophases. The ratio between the aqueous and oily
phases directly affected the mechanical, bioadhesive, and rheological
properties of the LCs. Over a 24 h period, the formulations released
between 1% and 70% of the AgNPs, showing proven efficacy against the
tested bacterial strains. The structural features of LC formulations
significantly influenced their biocompatibility in L-929 fibroblast
cells. The findings demonstrate that LC systems are promising controlled-release
platforms for AgNPs, combining antimicrobial activity and biocompatibility
for the treatment of bacterial skin infections.