Hydrophilic silicone elastomer with excellent cell adhesion capability - A promising material for ophthalmic micro-implants

For minimising tissue reactions of implants hydrophilic silicone elastomers feature a high potential to be utilised as material for micro-implants in ophthalmologic pathology. To estimate the biocompatibility we quantified cell viability of human primary fibroblasts from scleral (hSF) and choroideal (hCF) origin in direct contact test and evaluated cell adhesion and cell morphology with Phalloidin- TRITC stained hSF and EA.hy926. Mechanical properties were analysed by means of uniaxial tensile testing. Direct contact testing revealed a good biocompatibility from 65 to 70% relative cell viability for hCF and moderate viabilities (46 to 63%) for hSF. EA.hy926 and also hSF exhibited typical cell morphology on the silicones. Improvement of cell adhesion was observed with increasing amount of hydrophilic component. Mechanical testing shows a minor decrease in elongation at break from 236% to 155% with increasing amount of hydrophilic component. These findings indicate that the investigated silicones may ensure a reliable integration of implants into the ocular tissues.