Biocompatible neuronal stimulant-embedded poly(γ-benzyl-L-glutamate) peptide-based scaffolds promote differentiation, growth and functional maturation of human induced pluripotent stem cell-derived retinal ganglion cells

Abstract

BackgroundTo culture human induced pluripotent stem cells(hiPSCs)- derived retinal ganglion cells (RGCs) with appropriate structure and functionality is critical for cell therapy of optic nerve degeneration. In this study, we aimed to assess the effectiveness of three biocompatible scaffolds -poly(γ-benzyl-L-glutamate) (PBG)-based three-dimensional fibrous scaffolds in promoting the structural and functional maturation of hiPSC-derived RGCs. MethodsThe study investigated three scaffolds (1) PBG, (2) PBG with glutamic acid (PBGA20), and (3) PBGA20 with sodium salt (PBGA20-Na). The biocompatibility was evaluated in vivo with C57BL/6 mice. Neurite outgrowth was assessed using immunostaining for axon markers, while fluorescence-based Ca2+ imaging and patch-clamp technique were employed to measure neuronal calcium signaling and electrophysiological activity, respectively. Significant findingsAll three PBG-based scaffolds exhibited excellent biocompatibility in vivo and effectively supported the directional outgrowth of neurites from hiPSC-derived RGCs while the PBGA20-Na group demonstrated the most favorable outcomes. The presence of glutamic acid in PBGA20 and PBGA20-Na scaffolds led to an increase in calcium signaling within hiPSC-derived RGCs. HiPSC-derived RGCs cultured on PBGA20 and PBGA20-Na scaffolds exhibited an earlier onset of electrophysiological activities with lower thresholds. These promising results provide a foundation for potential sheet transplantation of hiPSC-derived RGCs as cell therapy for optic nerve regeneration.