Toward a Langmuir-monolayer-based protocol for assessing the mucoadhesion of gold nanoparticles intended for ophthalmological drug-delivery applications

This study aims to establish a Langmuir-monolayer-based protocol to assess the mucoadhesion of gold nanoparticles intended for ophthalmological drug-delivery applications. Using Langmuir monolayers to model the tear film and corneal epithelial membrane, mucins were found to interact with all tested lipids, showing a preference for saturated ones, whereas AuNPs presented a limited lipid binding. When combined with mucins, AuNPs do not alter membrane binding parameters such as the maximal insertion pressure (MIP), suggesting limited access to the interface region. Further analyses have shown that AuNPs form clusters at the interface, which may influence their interactions with lipids. This phenomenon is exacerbated by mucins, which hinder the dispersion of AuNPs due to their large molecular size and extensive glycosylation. A MUC2-derived peptide was therefore evaluated as an alternative, although less interactive overall, it showed distinct behavior with certain lipids and may serve as a promising model for assessing mucoadhesion studies.