Incorporation of low-oxidation graphene oxide into electrospun poly(ε-caprolactone) /gelatin scaffolds for human embryonic stem cell-derived retinal pigment epithelium cell transplantation.

Scaffold-based retinal pigment epithelium (RPE) transplantation is a candidate approach to preserve or recover vision for macular degeneration. Electrospun poly(ε-caprolactone) (PCL)/Gelatin (Gel) scaffolds have demonstrated support for cellular proliferation and function, yet their inadequate mechanical performance compromises surgical handling and deliverability. In this study, we incorporated low-oxidation graphene oxide (GO) into electrospun PCL/Gel scaffolds and evaluated their performance for human embryonic stem cell (hESC)-derived RPE cell transplantation. We found that the incorporation of low-oxidation GO improved scaffolds' WCA from 45.47 ± 8.44° to 27.48 ± 1.42° and tensile strength from 1.60 ± 0.06 MPa with an ultimate strain of 16% to 1.75 ± 0.07 MPa with an elongation at break of 44%, while maintaining fibrous formability and biocompatibility. The PCL/Gel/GO scaffolds supported RPE-specific protein expression (MITF, PAX6, CRALBP, ZO-1) and established favorable cell polarity, as indicated by apical Na+/K+-ATPase. Transmission electron microscopy assay also showed that the hESC-RPE cells on PCL/Gel/GO scaffolds formed apical microvilli. RNA-seq revealed the preservation of trophic factors and phagocytic function on PCL/Gel/GO scaffolds, which was further validated by augmented expression levels of CNTF, IGF1, and VEGFA, as well as improved fluorescent microsphere uptake capacity. Furthermore, the enhanced mechanical properties of the PCL/Gel/GO scaffold eliminated the need for additional treatment before implantation and facilitated surgical handling during implantation. In addition, the scaffold did not cause any observable short-term retinal dysfunction, indicating good short-term feasibility. Collectively, the scaffold structural features, RPE functional profiles, and surgical findings establish PCL/Gel/GO scaffolds as a versatile platform, warranting further investigation into their application in scaffold-based cell therapy for the treatment of macular degeneration.