Objective To explore the potential of nanofiber membrane of polycaprolactone (PCL) to constitute tissueengineered retinal pigment epithelium (RPE).Methods The embryonic stem cells (ESC) were differentiated into retinal pigment epithelium (ESCRPE) cells by spontaneous differentiation methods.The nanofiber membrane of PCL was prepared by electrospinning

and the topography of PCL nanofiber membrane was observed by scanning electron microscope.The viability of ESCRPE cells treated by the extracts of PCL nanofiber membrane was studied by CCK-8.After the ESC-RPE cells were cultured on the PCL nanofiber membrane

transmission electron microscope and immunostaining were used to detect the ultrastructure and the expression of RPE markers of tissueengineered RPE

respectively.Moreover

neural retinas of rats were co-cultured with tissueengineered RPE to detect the capacity to phagocytize photoreceptor outer segment.Results ESC-RPE cells were positive for MITF and PAX6.The PCL nanofiber membrane was porous with high biocompatibility.The tissueengineered RPE based on PCL nanofiber membrane showed typical ultrastructure of RPE cells.The tissueengineered RPE was positive for ZO-1 and showed polarized expression of NaKATPase.Besides

the tissueengineered RPE was able to phagocytize photoreceptor outer segment.Conclusion PCL nanofiber membrane is favor for the growth of RPE cells

and it can be used as a scaffold to constitute tissueengineered RPE.