Dual-sized inverted colloidal crystal scaffolds grafted with GDF-8 and Wnt3a for enhancing differentiation of iPS cells toward islet β-cells

Abstract Background Scaffolds containing two kinds of regular pore size that support differentiation and proliferation of induced pluripotent stem cells (iPSC) are important approaches to artificial pancreas. Methods This study aimed to differentiate iPSC in dual-sized gelatin (Gel)-alginate (Alg)-hyaluronic acid (HA) scaffolds containing inverted colloidal crystal (ICC) topography with 70-µm and 160-µm pore sizes for insulin production. The pore surface of dual-sized Gel-Alg-HA ICC scaffolds was grafted with growth differentiation factor 8 (GDF-8) and Wnt3a, and treated with retinoic acid (RA) and noggin to improve the differentiation of iPSC toward endodermic cells, and then islet cells. Findings An increasing weight percentage of Gel increased the adhesion efficiency of iPSC. Moreover, Alg and HA helped to promote the proliferation and survival rate of iPSC, which resulted in a higher availability of iPSC for differentiation into insulin-production cells. Immunofluorescence staining, flow cytometry and western blot evidenced that dual-sized Gel-Alg-HA ICC scaffolds grafted with GDF-8 and Wnt3a enhanced the differentiation of iPSC into endodermic cells. When subsequent treatment with RA and noggin, endodermic cells differentiation into insulin-production cells in the scaffolds were improved. Precisely controlling the physical and biomedical properties of dual-sized Gel-Alg-HA ICC scaffolds can guide iPSC to differentiate first into endodermic cells, and then into pancreatic β-cells for diabetic treatment.