Abstract
Purpose: :
Retinal degenerations cause permanent visual loss and affect millions world-wide. Here we describe the use of a biodegradable polymer scaffold to induce differentiation and deliver retinal progenitor cells for cell replacement therapy. In this study, we engineered and analyzed a micro-fabricated polymer, poly(glycerol sebacate) (PGS) scaffold, whose useful properties include biocompatibility, elasticity, porosity, and a microtopology conducive to mouse retinal progenitor cell (RPC) differentiation.
Methods: :
GFP-positive murine RPCs were cultured on scrollable PGS for up to seven days. Cell adhesion to and proliferation on PGS scaffolds were determined by fluorescence analysis. Differentiation was analyzed using immunohistochemistry and RT-qPCR. PGS scaffolds with adherent RPCs were then transplanted ex vivo onto wild-type and rhodopsin -/- mouse retinal explants for one week. Composites were also transplanted in vivo in wild-type and rhodopsin -/- mice for 30 days. PGS-RPC composite retinal explants and transplants were cryosectioned in 8µm sections for analysis. GFP-positive mRPCs were imaged to measure migration and differentiation in each retinal layer.
Results: :
In vitro proliferation assays revealed that PGS held up to 86,610 (±9,993) mRPCs per square millimeter, which were retained through simulated transplantations. mRPCs adherent to PGS differentiated toward mature phenotypes as evidenced by changes in mRNA, protein levels, and enhanced sensitivity to glutamate. Transplanted composites demonstrated long-term mRPC survival and migrated cells exhibited mature marker expression in host retina.
Conclusions: :
These results suggest that combining mRPCs with PGS scaffolds for subretinal transplantation is a practical strategy for advancing retinal tissue engineering as a restorative therapy.
Keywords: regeneration • retina • transplantation