Polybenzyl Glutamate Biocompatible Scaffold Promotes the Efficiency of Retinal Differentiation toward Retinal Ganglion Cell Lineage from Human-Induced Pluripotent Stem Cells

Abstract

Optic neuropathy is one of the leading causes of irreversible blindness caused by retinal ganglion cell (RGC) degeneration. The development of induced pluripotent stem cell (iPSC)-based therapy opens a therapeutic window for RGC degeneration, and tissue engineering may further promote the efficiency of differentiation process of iPSCs. The present study was designed to evaluate the effects of a novel biomimetic polybenzyl glutamate (PBG) scaffold on culturing iPSC-derived RGC progenitors. The iPSC-derived neural spheres cultured on PBG scaffold increased the differentiated retinal neurons and promoted the neurite outgrowth in the RGC progenitor layer. Additionally, iPSCs cultured on PBG scaffold formed the organoid-like structures compared to that of iPSCs cultured on cover glass within the same culture period. With RNA-seq, we found that cells of the PBG group were differentiated toward retinal lineage and may be related to the glutamate signaling pathway. Further ontological analysis and the gene network analysis showed that the differentially expressed genes between cells of the PBG group and the control group were mainly associated with neuronal differentiation, neuronal maturation, and more specifically, retinal differentiation and maturation. The novel electrospinning PBG scaffold is beneficial for culturing iPSC-derived RGC progenitors as well as retinal organoids. Cells cultured on PBG scaffold differentiate effectively and shorten the process of RGC differentiation compared to that of cells cultured on coverslip. The new culture system may be helpful in future disease modeling, pharmacological screening, autologous transplantation, as well as narrowing the gap to clinical application.

Retinal Organoids: Cultivation, Differentiation, and Transplantation

“…Because the glutamic acid pathway is related to the development of neurons, it promotes an increase in RGCs and axon growth in human iPSC–derived Ros. Moreover, compared with ordinary culture medium, hiPSC on PBG takes a shorter time to form organoids and differentiate into RGC ( Chen et al, 2019 ). Previous studies have designed the electrospun scaffold, which can simulate the growth process of RGC axons in vivo , thereby promoting the survival of RGCs and guiding the axons to project along the radial direction of the scaffold ( Kador et al, 2013 ).…”

Retinal organoids: a window into human retinal development

“…longer-term maintenance of lamination (Achberger et al, 2019;Chen et al, 2019;DiStefano et al, 2018;Dorgau et al, 2019;Hertz et al, 2013;Wörsdörfer et al, 2019). In vivo, the lens and ciliary body biosynthesise ECM components that may act as guidance cues for RGC outgrowth.…”

“…Bioreactor cultures have been demonstrated to improve laminar stratification and increase formation of complex structures, due to improved aeration and nutrient distribution ( DiStefano et al, 2018 ; Ovando-Roche et al, 2018 ). However, these cultures are still imperfect and emerging technologies in biomaterials, scaffolds, de-cellularisation and vascularisation may encourage cell survival and longer-term maintenance of lamination ( Achberger et al, 2019 ; Chen et al, 2019 ; DiStefano et al, 2018 ; Dorgau et al, 2019 ; Hertz et al, 2013 ; Wörsdörfer et al, 2019 ). In vivo , the lens and ciliary body biosynthesise ECM components that may act as guidance cues for RGC outgrowth.…”

Functional 3-Dimensional Retinal Organoids: Technological Progress and Existing Challenges

“…Without vasculature, the size of an organoid is limited to the diffusional limit of oxygen (Radisic et al, 2006). This problem may be resolved by applying new technological approaches-for example, optimization of scaffold porosity (Chen et al, 2019), inclusion of bioreactor (Ovando-Roche et al, 2018), incorporation of oxygen delivery mechanisms (Li et al, 2012), retina-on-a-chip (Achberger et al, 2019b), 3D bioprinting of vascularized tissues (Richards et al, 2017), and co-culture with mesodermal progenitor cells (Worsdorfer et al, 2019) are areas of current research.…”