Repair effects of thermosensitive hydrogels combined with iPSC-derived corneal endothelial cells on rabbit corneal endothelial dysfunction

Considering the limitations of human corneal endothelial cell proliferation as well as the severe shortage of corneal donations, it is imperative to develop improved methods of corneal endothelial cell transplantation. The purpose of this study was to construct a modified corneal endothelial cell transplantation approach using thermosensitive hydrogels combined with induced pluripotent stem cells (iPSCs)-derived human corneal endothelial cells (hCECs). In this study, thermosensitive hydrogels hydroxypropyl chitin/carboxymethyl chitosan (HPCH/CMCS) were fabricated, and their hydrogels properties and biocompatibility were investigated. Our results demonstrated that HPCH/CMCS hydrogels exhibited superior transparency, appropriate mechanical properties and favorable biocompatibility. A two-step induction method of small molecule compounds was employed, by which iPSCs were differentiated into hCECs via neural crest cells (NCCs). Additionally, a rabbit corneal endothelial dysfunction model was established in vivo, aiming to evaluate the safety and effectiveness of the combined method. Slit lamp microscope results indicated that significant transparency improvement could be noted in HPCH/CMCS/hCECs group (P = 0.006), whereas the corneal transparency was not homogeneous in different areas. Moreover, histological examinations and immunofluorescence analysis revealed that HPCH/CMCS/hCECs group showed a higher density of corneal endothelial cells and positive expressions of related markers. This study may provide ideas and experimental basis for the combined application of hydrogels and iPSCs-derived corneal endothelial cells for corneal endothelial dysfunction. STATEMENT OF SIGNIFICANCE: Corneal transplantation is the most effective treatment for corneal endothelial dysfunction, which is challenged by issues such as corneal donor shortages and immune rejection. In this study, we proposed a combined transplantation method of cells and hydrogels for corneal endothelial dysfunction. We modified the protocols to obtain corneal endothelial cells from iPSCs by a two-step induction method. Besides, thermosensitive hydrogels with satisfactory biocompatibility and degradability were fabricated as fixation and support carriers of iPSCs-derived corneal endothelial cells for in vivo transplantation. Experimental results demonstrated that this method could locally repair corneal endothelial dysfunction in rabbits, with the repaired corneas expressing relevant markers. This study presented a preliminary attempt to combine hydrogels and cells for corneal endothelial dysfunction.