# Enhanced antibacterial properties of amoxicillin-loaded silver nanoparticles against Methicillin-resistant Staphylococcus aureus: physicochemical characterization, anti-virulence activity, and biofilm inhibition

## TL;DR

Researchers developed amoxicillin-loaded silver nanoparticles to combat drug-resistant Staphylococcus aureus, showing strong antibacterial effects and reduced biofilm formation.

## Contribution

The study introduces a novel nanocarrier system combining silver nanoparticles and acacia extracts to enhance amoxicillin's efficacy against MRSA.

## Key findings

- Amoxicillin-loaded silver-acacia nanoparticles inhibited MRSA growth with an MIC of 2 mg/mL.
- The nanoparticles reduced biofilm formation by 80% and suppressed hemolytic activity.
- The effective concentration was cytocompatible with endothelial cells.

## Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) presents significant challenges in healthcare and community settings due to its diverse virulence factors and increasing resistance to conventional antibiotics. Given the scarcity of effective treatments, developing innovative antibacterial strategies is essential. This study explores the potential of silver nanoparticles conjugated with acacia extracts as nanocarriers for amoxicillin to enhance antibacterial efficacy and circumvent resistance mechanisms in MRSA. The synthesized amoxicillin-loaded silver-acacia nanoparticles were characterized for their physicochemical properties, revealing spherical morphology with a minimum particle size of approximately 230 nm, a polydispersity index of 0.3, and a high negative zeta potential of −32 mV as confirmed by transmission electron microscopy. In vitro assays demonstrated that these nanoparticles significantly inhibited bacterial growth, achieving a reduction at a minimum inhibitory concentration (MIC) of 2 mg/mL. At this concentration, biofilm formation by MRSA was inhibited by 80%, as verified by scanning electron microscopy, and hemolytic activity on blood agar was completely suppressed. While a dose-dependent cytotoxic effect on endothelial cells was observed, the MIC concentration remained cytocompatible (p < 0.05). These findings underscore the promise of amoxicillin-loaded silver-acacia nanoparticles as potent antibacterial agents with minimal cytotoxicity at effective doses. This study highlights the potential of nanotechnology-enabled drug delivery to repurpose amoxicillin and offers a novel platform for combating multidrug-resistant MRSA infections, which may inform future therapeutic developments.