Antibacterial Activity of Silver Nanoparticle-Loaded Soft Contact Lens Materials: The Effect of Monomer Composition

ABSTRACT

Purpose: In the present work, the effect of monomer composition on silver nanoparticles’ (SNPs) binding capacity of hydrogels was investigated and their antibacterial efficacy was evaluated.

Materials and methods: Three series of poly-hydroxyethyl methacrylate (HEMA) hydrogels were prepared using methacrylic acid (MAA), methacrylamide (MAAM), and 4-vinylpyridine (4VP) as co-monomers, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. SNPs binding capacity of hydrogels was evaluated in different concentrations (2, 10, and 20 ppm). In vitro antibacterial activity of SNP-loaded hydrogels was studied against Pseudomonas aeruginosa (P. aeruginosa) isolated from patients’ eyes. Then, inhibitory effect of hydrogels in biofilm formation was evaluated in the presence of Staphylococcus epidermidis (S. epidermidis) (DSMZ 3270).Results: Our data indicated that poly(HEMA-co-MAA-co-EGDMA) had superior binding affinity for SNPs in comparison with other hydrogels. All SNP-loaded hydrogels demonstrated excellent antimicrobial effects at all times against P. aeruginosa and S. epidermidis after soaking in 10 and 20 ppm SNP suspensions. Scanning electron microscope (SEM) images revealed excellent inhibitory effect of SNPs against biofilm formation on the surface of the hydrogels.Conclusions: This study indicated the effect of monomer compositions in SNP loading capacity of poly(HEMA) hydrogels and antibacterial efficacy of SNP-loaded hydrogels against P. aeruginosa and S. epidermidis, but further in vivo evaluation is necessary.

Keywords:

• Antimicrobial effect
• biofilm
• hydrogels
• poly-hydroxyethyl methacrylate
• silver nanoparticles

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Funding

We gratefully acknowledge the vice chancellor of research, Mashhad University of Medical Sciences, for providing financial support through grant number 900456.

Additional information

Funding

We gratefully acknowledge the vice chancellor of research, Mashhad University of Medical Sciences, for providing financial support through grant number 900456.