Investigation of the effectiveness of gelatin hydrolysate in human iPS-RPE cell suspension transplantation.

INTRODUCTION

The retinal pigment epithelium (RPE) plays essential roles in maintaining retinal functions as well as choroidal capillaries and can lead to visual disorders if dysfunctional. Transplantation of human-induced pluripotent stem cell-derived RPE (hiPSC-RPE) is a promising therapy for such RPE impaired conditions including age-related macular degeneration. The challenge with cell suspension transplantation is targeted delivery of graft cells and undesired cell reflux. Gelatin hydrolysate, a soluble variant with specific molecular weight distribution, is examined in this study for its potential use in hiPSC-RPE suspension transplantation, particularly in reducing cell reflux and enhancing RPE engraftment.

METHODS

A retinal bleb model was created using polydimethylsiloxane (PDMS) soft lithography to quantify cellular reflux. We examined the effects of gelatin hydrolysate on the hiPSC-RPE of various aspects of cell behavior and performance such as cell viability, hypoxia reaction, morphology, induction of inflammation and immune responses.

RESULTS

Gelatin hydrolysate at 5 % concentration effectively mitigated cell reflux in vitro mimic, improved cell viability, reduced cell aggregation, and had an inhibitory effect on hypoxic reactions due to cell deposition with hiPSC-RPE. Additionally, gelatin hydrolysate did not affect cell adhesion and morphology, and decreased the expression of major histocompatibility complex class II molecules, which suggests reduced immunogenicity of hiPSC-RPE.

CONCLUSION

Gelatin hydrolysate is considered a valuable and useful candidate for future regenerative therapies in hiPSC-RPE suspension transplantation.