Abstract
P 070
Comparison of biomaterials for subretinal transplantation of pigment epithelial cell sheets
Anna Katharina Salz, Gabriele Thumann.
RWTH Aachen, Universitäts-Augenklinik, IZKF Biomat., Aachen
Objective
One therapeutic approach for AMD is the replacement of degenerated RPE cells by transplanted pigment epithelial cells. Since previous studies have shown that transplanted cell suspensions do not form a monolayer in the subretinal space it may be necessary to establish pre-cultured cell monolayers on a biodegradable substratum before transplantation that serves as a temporary Bruch’s membrane prosthesis until the cells will reconstruct the native Bruch’s membrane and photoreceptor interface. Here we investigated and compared the in vitro growth characteristics of pigmented cells and in vivo biocompatibility of natural and synthetic substrata.
Methods
After the surface morphological characteristics and hydrophilic properties of ultrathin (7 μm) equine collagen type I membranes, human amniotic membranes, silk and polylactic acid (PLA) membranes produced from electrospun nanofibers, ARPE-19 and primary bovine RPE and IPE cells were cultured on the membranes and investigated for morphology and viability. Biocompatibility of materials was evaluated by subconjunctival transplantation in rabbits.
Results
Of the four materials the collagen type I membrane shows best hydryophilicity and has surface morphological characteristics similar to Bruch’s membrane. Even though pigment epithelial cells formed monolayers on all membranes, viability was best on collagen type I followed by amniotic membrane, polylactic nanofibers and silk membranes. Transplantation in rabbits revealed good autostability of all materials except PLA fibers. After 5 weeks subconjunctivally no inflammatory reaction was observed for the collagen type I and amniotic membranes, whereas PLA and silk caused a mild inflammatory reaction.
Conclusions
A comparison of collagen type I, amniotic membrane, polylactic acid and silk membranes as support for the growth of pigment cells demonstrated that collagen supports growth and viability better than amniotic membranes and far better than polylactic and silk membranes. The superiority of the ultrathin collagen membrane may be the result of better surface characteristics and higher hydrophilicity. In addition, the collagen membranes were also more biocompatible when transplanted subconjunctivally. Between natural and synthetic materials used as scaffold, natural materials as collagen type I and amniotic membrane have the most adequate features for cell growth of pigment epithelial cells and subsequent subretinal transplantation.
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