Antimicrobial nanocoatings and films for contact lenses: progress and promise

Microbial keratitis is a serious complication of contact lens wear, occurring in 2-24 cases per 10,000 wearers annually. Increasing lens use, especially for myopia control in children, highlights the need for safer designs. Antimicrobial coatings and films offer a promising strategy to reduce infection risk. Recent approaches include metallic and polymeric nanocoatings, antimicrobial peptides (AMPs), peptidomimetics, and hybrid systems that prevent microbial adhesion and biofilm formation while maintaining lens biocompatibility.

This review examines advances in antimicrobial nanocoatings for contact lenses, focusing on metallic nanoparticles (silver, zinc oxide, titanium dioxide), organo-selenium coatings, polymeric layers, AMPs such as melimine and Mel4, and emerging peptidomimetics. Literature from PubMed, Scopus, and Web of Science (2008-2025) was analyzed. Key topics include coating techniques (surface grafting, dip-coating, plasma treatment), antimicrobial mechanisms, and outcomes from preclinical and clinical trials. Limitations such as nanoparticle toxicity, peptide degradation, and regulatory hurdles are discussed.

Antimicrobial nanocoatings show strong potential, achieving >3-log₁₀ bacterial reductions and reducing corneal infiltrative events in trials. Future work should focus on hybrid, stimuli-responsive coatings that activate under infection-specific conditions, ensure long-term safety, and meet manufacturing and regulatory requirements.