neural retinal cell can be damaged in a variety of degenerative eye diseases. Cell replacement therapy could be a potential cure for these diseases. Retinal pigment epithelium (RPE) is a pigmented cell monolayer situated between the neuroretina and the choroid and has the ability to differentiate into different neural retinal linage. In this study we evaluated proliferation and differentiation of RPE cells on alginate/gelatin (A/G) substrate.

RPE was isolated from neonatal human globes and cultured in DMEM/F12 supplement with 10% FBS. Alginate / gelatin substrate with 20:80 weight ratios were prepared. Passage 4 of RPE cells was cultivated on substrate and proliferation of cells was determined in different culture conditions of DMEM/F12; DMEM/F12 supplement with 10% FBS or DMEM/F12 supplemented with 30% HAF, by MTT and cell proliferation assay. Immunocytochemistry and real-time RT-PCR were performed to evaluate the effect of substrate on RPE cells differentiation.

significant increase in cell proliferation was observed in RPE cells on (A/G) substrate when compared to cells cultured on uncoated polystyrene substrate. Immunocytochemistry and real-time RT-PCR data revealed that densely packed suspended colonies of hRPE cells in DMEM/F12 culture condition have undergone dominant trans-differentiation to amacrine, Rod photoreceptor and bipolar neural cells, while small adhered clusters of hRPE cells in HAF and FBS have undergone dedifferentiation to neural retinal progenitor cells (RPC). These RPCs were able to generate amacrine, rod photoreceptors and bipolar neuron cells as retinal terminally differentiated cells.

we found that alginate/ gelatin substrate could support survival and growth of hRPE cells and induced differentiation of cells to different kinds of retinal neural cells and neural progenitor cells.