In vitro effect of a corrosive hostile ocular surface on candidate biomaterials for keratoprosthesis skirt

Aim: Keratoprosthesis (KPro) devices are prone to long-term corrosion and microbiological assault. The authors aimed to compare the inflammatory response and material dissolution properties of two candidate KPro skirt materials, hydroxyapatite (HA) and titania (TiO₂) in a simulated in vitro cornea inflammation environment. Methods: Lipopolysaccharide-stimulated cytokine secretions were evaluated with human corneal fibroblasts on both HA and TiO ₂. Material specimens were subjected to electrochemical and long-term incubation test with artificial tear fluid (ATF) of various acidities. Topography and surface roughness of material discs were analysed by scanning electron microscopy and atomic force microscopy. Results: There were less cytokines secreted from human corneal fibroblasts seeded on TiO₂ substrates as compared with HA. TiO₂ was more resistant to the corrosion effect caused by acidic ATF in contrast to HA. Moreover, the elemental composition of TiO₂ was more stable than HA after long-term incubation with ATF. Conclusions: TiO₂ is more resistant to inflammatory degradation and has a higher corrosion resistance as compared with HA, and in this regard may be a suitable material to replace HA as an osteo-odonto-keratoprosthesis skirt. This would reduce resorption rates for KPro surgery.