# Bacterial Cellulose Hydrogel Incorporating Silver Nanoparticles: A Nanobiotechnological Approach for Skin Infections Caused by MRSA and MRSE

## TL;DR

A new hydrogel with silver nanoparticles shows strong potential to treat skin infections caused by drug-resistant bacteria.

## Contribution

A bacterial cellulose hydrogel loaded with silver nanoparticles is proposed as a novel therapeutic strategy for MRSA and MRSE infections.

## Key findings

- The hydrogel with silver nanoparticles showed effective antibacterial activity against S. aureus and S. epidermidis.
- SEM confirmed biofilm disruption and cell eradication by the AgNP-loaded hydrogel.
- MIC and MBC values indicated the hydrogel's potent antimicrobial properties.

## Abstract

Background: Healthcare-associated infections (HAIs) caused by biofilm-forming Staphylococcus aureus and Staphylococcus epidermidis represent a major public health challenge due to their high resistance and involvement in skin, wound, and soft-tissue infections. In this context, silver nanoparticles (AgNPs) incorporated into Gluconacetobacter sp. bacterial cellulose hydrogel emerge as a promising alternative therapeutic strategy. Methods: AgNPs and hydrogels were synthesized and characterized using physicochemical and morphological analyses. Antibacterial activity was assessed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) following CLSI guidelines, as well as by time–kill curve assays. Antibiofilm activity was evaluated through the determination of minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) using crystal violet staining, complemented by scanning electron microscopy (SEM) and Congo red agar method. Results: The hydrogel exhibited a three-dimensional microfibrillar structure characteristic of bacterial cellulose, while AgNPs showed rod-shaped, oval, and triangular morphologies, with particle sizes of 35 and 59 nm and positive zeta potentials. MIC and MBC values ranged from 6.25 to 50 µg/mL across all tested formulations and strains. Time–kill assays demonstrated significant bacterial population reductions after 6 to 9 h of exposure. MBIC values ranged from 0.78 to 50 µg/mL, whereas MBEC values ranged from 1.56 to >100 µg/mL. SEM analyses confirmed biofilm disruption, cell eradication, and a reduction in extracellular polysaccharides, particularly for AgNPs incorporated into the hydrogel. Conclusions: Overall, the results highlight the strong antibacterial and enhanced antibiofilm potential of AgNP-loaded bacterial cellulose hydrogel against S. aureus and S. epidermidis, supporting its potential application in infection treatment.