Optimisation of Polymer Scaffolds for Ocular Cell Transplantation

Abstract

Purpose: : The retinal pigment epithelium would be the primary target for cellular replacement in degenerative ocular diseases such as age related macular degeneration. Transplantation of cells into the eye as a suspension has a number of disadvantages including cell death and incorrectly localised or disorganised grafts. Recent studies have demonstrated that growth of RPE cells on polymer scaffolds can facilitate the transplantation of cells as an intact monolayer which may reduce cell death by up to 10 fold (1). However there have only been limited investigations to determine the optimal polymer composition for such scaffolds.

Methods: : Using a technique described by (2). We manufactured and evaluated five different blends of poly(L-lactic acid) (PLLA) with poly(D, L-lactic-glycolic acid) (PLGA). Scanning electron microscopy (SEM) and ¹³C Nuclear magnetic resonance spectroscopy were used to characterise the polymer surface and verify the ratios produced. Polymer surface chemistry was modified using the extracellular matrix protein laminin. The polymer blends were then seeded with ARPE-19 cells and maintained in culture for up to 4 weeks. Cell adherence and proliferation were assessed using SEM and immunofluorescence. Cell survival was quantified by measurement of apoptosis and cell membrane integrity. Maintenance of phenotypic characteristics was also investigated using immunocytochemistry.

Keywords: transplantation • retinal pigment epithelium • cell survival