Preparation, characterization and antimicrobial study of a hydrogel (soft contact lens) material impregnated with silver nanoparticles

Purpose: Contact lenses that incorporate antimicrobial properties may reduce the risk for microbial-associated adverse events for lens wearers. The aim of this study was to assess the antimicrobial effects of silver nanoparticles (NP) when impregnated in a hydrogel material. Methods: Hydrogel disks, used as a proxy for soft contact lenses, were prepared with silver NPs to add an antimicrobial effect to the polymer. Six groups of disks were created, each with a different concentration of silver NPs. The antimicrobial effect of the hydrogels against Pseudomonas aeruginosa (ATCC15442) and Staphylococcus aureus (ATCC6538) was evaluated at 6, 24,48 and 72 h. Results: Silver NP concentrations ranged from 20.71 to 98.06 mu g/disk. All groups demonstrated excellent antibacterial effects against P. aeruginosa at each time point. After 6 h all disks didn't exhibit desirable antibacterial activity against S. aureus; whereas except those with 20.71 mu g silver NPs showed antibacterial activity at 24 h and only the disks with 57.13 and 98.06 mu g silver NPs showed antimicrobial activity at 48 and 72 h. Conclusions: The development of contact lenses made of a silver NP-impregnated hydrogel material may bring antimicrobial effects sufficient to decrease the risk of microbial-related adverse events for lens wearers. (C) 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.