Fabrication of stable hydrophilic coating on poly(2-hydroxyethyl methacrylate) hydrogel contact lens for tear protein deposition resistance based on oxygen plasma treatment and layer-by-layer self-assembly

Abstract Hydrophobicity is a main cause of tear protein deposition on poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel contact lenses. Surface coating is the simplest approach for hydrophilicity improvement, but its stability is still challenging. This study developed a combined technique based on oxygen plasma treatment and layer-by-layer (LBL) self-assembly of poly(allylamine hydrochloride) (PAH) and nano-silica (n-SiO 2 ) to enhance the stability of hydrophilic coating on pHEMA hydrogel con