Strategies to improve functional integration of transplanted photoreceptors

The final outcome of the retinal degenerative diseases is the massive loss of photoreceptors, resulting in irreversible visual impairment which lacks effective treatment at present.As a potential therapeutic approach, photoreceptor transplantation can be used to restore retinal function to a certain extent by replacing the lost photoreceptors and rebuilding the retinal circuits.However, the discovery of material exchange unveiled a number of problems in previous studies, including low cellular integration, insufficient outer segment and synapse formation, highlighting the challenges of clinical translation.To explore the possibility of increasing the functional integration of photoreceptors, this article reviewed a variety of strategies, including selection of the transplanted cells with optimal developmental stage to enhance the interaction with the host retina, disruption of the outer limiting membrane and alleviation of retinal remodeling to improve the migration and integration of the transplanted photoreceptors, regulation of immunity can be used to reduce microglial activation to create a better host microenvironment for transplantation, use of retinal sheets or biological scaffolds to improve photoreceptor organization, rational development and use of biomaterials to optimize the physiological microenvironment of the transplanted cells, adequate evaluation of surgical parameters to reduce the effect of surgery on the transplanted cells and the host retina.

Retinal degeneration; Stem cell transplantation; Cell therapy; Photoreceptor; Regenerative medicine