Biocompatibility of Collagen Type 1 Scaffolds for Subretinal Transplantation

Abstract

Purpose: : To examine the biocompatibility and biodegradation of collagen type 1 membranes for use as scaffolds for the culture of RPE and IPE cells to be transplanted to the subretinal space to replace degenerated RPE cells in retinal degeneration diseases.

Methods: : DTAF-stained, ultra-thin (7 µm) collagen type 1 membranes were transplanted subconjunctivally and subretinally in rabbit eyes and followed for up to 23 weeks. Ocular inflammation and membrane integrity were examined histologically.

Results: : No evidence of inflammation was observed at the conjunctiva or in the subretinal area during follow-up. The membrane remained stable and appeared intact up to 12 weeks subconjunctivally as well as subretinally. Signs of degradation were observed at 17 weeks and by 23 weeks the membrane was completely degraded as evidenced by the total lack of fluorescence.

Conclusions: : Ultra-thin collagen type 1 membranes implanted subconjunctivally and subretinally do not elicit an inflammatory response in rabbit eyes. The membrane remains stable for 12 weeks, but by 17 weeks degradation begins and the membranes are completely degraded by 23 weeks. The time course of degradation suggests that these membranes are ideal to transplant cell monolayers to the subretinal space because they provide sufficient time for the cells to integrate into the retinal-choroid complex before they degrade.

Keywords: age-related macular degeneration • transplantation • vitreoretinal surgery