Aim: To evaluate a variety of copolymers as suitable scaffolds to facilitate retinal pigment epithelium (RPE) transplantation.
Methods: Five blends of poly(L-lactic acid) (PLLA) with poly(D, L-lactic-glycolic acid) (PLGA) were manufactured by a solid-liquid phase separation technique. The blends were 10:90, 25:75, 50:50, 75:25, 90:10 (PLLA:PLGA). All blend ratios were validated by nuclear magnetic resonance spectroscopy. Samples of polymer blends were coated with laminin. Coated and uncoated blends were seeded with a human RPE cell line. Cell attachment, viability and retention of phenotype were assessed.
Results: As the lactide unit content increased pore size generally became smaller. The 25:75 PLLA:PLGA blend was the most porous (44%) and thinnest (134μ) scaffold produced. ARPE-19 cells survived with minimal cell death and maintained their normal phenotype for up to four weeks.. Cell density was maintained with only one of the fabricated ratios (25% PLLA:75% PLGA). There was a consistent decrease in apoptotic cell death with time on laminin coated samples of this blend. A decrease in polymer thickness concomitant with an increase in porosity characteristic of degradation was observed with all polymer blends.
Conclusions: This study demonstrates that a 25:75 copolymer blend of PLLA:PLGA is a potentially useful scaffold for ocular cell transplantation.