Stem/Progenitor Cells and Biodegradable Scaffolds in the Treatment of Retinal Degenerative Diseases.

Abstract

Visual impairment caused by retinal degeneration is primarily attributed to the irreversible degradation of retinal neurons or the adjacent retinal pigment epithelium (RPE). No efficient clinical therapies to restore or improve visual ability are currently available. Cell therapy has been touted as a promising strategy to overcome this challenge. This review aims to depict the effects and progresses of using stem/progenitor cells and biodegradable scaffolds in the treatment of retinal degenerative diseases, as well as discuss the challenges and opportunities of cell-based therapy for the future clinical application. Progenitor/stem cells may be obtained from both ocular and non-ocular tissues. The former mainly includes retinal progenitor cells (RPCs), whereas the latter comprises embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), which have been utilized in stem cell replacement therapy studies ranging from proof-of-concept animal models to clinical trials in humans. Mesenchymal stem cells (MSCs), which represent another type of stem cells, secrete anti-inflammatory cytokines and neurotrophic factors that protect and nourish retinae. Although the origins of seed cells are diverse, the cell survival rate after transplantation in vivo is limited. Therefore, cell delivery techniques that combine seed cells with polymer scaffolds are applied to improve the cell survival rate. This review summarized the different resources of stem cells and the significant progresses in the treatment of retinal degeneration combined with seed cells and scaffolds, which may pave the way for future clinical therapies.