Biodegradable poly(α-hydroxy ester) blended microspheres as suitable carriers for retinal pigment epithelium cell transplantation.

Abstract

Five blends of poly(L-lactic acid) (PLLA) with poly(D,L-lactic-co-glycolic acid) (PLGA) were used to prepare microcarriers by a solvent evaporation technique. Microcarriers were evaluated as suitable scaffolds to facilitate retinal pigment epithelium (RPE) cell transplantation. The blend ratios were 90:10, 75:25, 50:50, 25:75, 10:90 (PLLA:PLGA). Samples of each microcarrier blend were coated with an extracellular matrix protein. Coated and uncoated microcarriers were seeded with a human RPE cell line. As the lactide unit content increased the size of microcarriers generally became larger and the surface more irregular. Cells remained proliferative and retained phenotype as confirmed by immunocytochemistry. Blends rich in PLLA were superior for maintenance of RPE cell viability. This study demonstrates for the first time the feasibility of using microcarriers as a vehicle for retinal cell transplantation for ocular disease.