Abstract
Purpose :
Optic neuropathies threaten vision with irreversible retinal ganglion cell (RGC) degeneration. Stem cell research holds promise, particularly with human induced pluripotent stem cells (hiPSCs). Based on our prior work utilizing poly(γ-benzyl-L-glutamate)-based (PBG) scaffolds to facilitate hiPSC-derived RGC differentiation and neurite outgrowth, this in vitro study explores the scaffolds' electroactive properties for inducing functional maturation of hiPSC-derived RGCs without added conductive materials or electrical stimulation.
Methods :
Cultured hiPSC-derived RGCs were subjected to various biodegradable PBG scaffolds, including modifications such as PBG with glutamic acid (PBGA20) and PBGA20 with sodium salt (PBGA20-Na), which were biocompatible when implanted into C57BL/6 mice’s eyes. Electrophysiological activity was recorded through whole-cell patch-clamp detection, revealing spontaneous beating RGCs with functional synaptic inputs.
Results :
Immunofluorescence staining confirmed successful RGC differentiation and the expression of neuronal and RGC-associated markers on all three PBG-based scaffolds. Notably, PBGA20-Na exhibited superior electrophysiological activity with enhanced ionic conductivity. On Day 60, hiPSC-derived RGCs on PBGA20-Na responded clearly to current injections, firing action potentials at 70 nA. By Day 100, robust action potentials were evoked at a lower current (50 nA), surpassing cover glass responses. Statistical analysis confirmed significantly stronger electrophysiological activities on PBGA20 and PBGA20-Na scaffolds than PBG and control groups. Moreover, PBGA20-Na showed higher action potential peaks, indicating advanced electrophysiological functionality.
Conclusions :
This study highlights the pivotal role of PBGA20-Na scaffolds in advancing electrophysiological functionality in hiPSC-derived RGCs. With accentuated biocompatibility and robust electrophysiological activity provision, this scaffold is a promising candidate for future vision restoration therapies.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.