Long-term survival of retinal cell cultures on retinal implant materials

The aim of the present study was to evaluate cell adhesion and cell survival of mammalian retinal neurons on different materials used for the production of multi-photodiode arrays (MPDAs) intended for implantation in the subretinal space of patients suffering from progressive photoreceptor cell loss. The survival rates of different types of retinal neurons and glia cells were monitored by conventional histochemical techniques and immunocytochemistry up to 4 weeks. Whereas most of the materials tested showed good biocompatibility, cell survival of retinal glia and neurons was markedly reduced on titanium nitride (TiN), especially for culturing periods longer than 2 weeks. The effect was not mediated by diffusible factors released from TiN material. In conclusion, most of the materials tested in this study are suitable for the production of functional MPDAs and no complications are to be expected from long-term implantations of them in the subretinal space.