IPSCs-laden GDF8-grafted aldehyde hyaluronic acid-polyacrylamide inverted colloidal crystal constructs with controlled release of CHIR99021 and retinoic acid to generate insulin-producing cells

Abstract

Recent advances in attempting maturation of pancreatic β cells derived from induced pluripotent stem cells (iPSCs) have initiated a gateway to developing innovated materials and protocols for artificial pancreas implantation in diabetic management. In this study, we proposed a tissue-engineering scheme using iPSCs-laden aldehyde hyaluronic acid (AHA)-polyacrylamide (PAAM) inverted colloidal crystal constructs (ICCCs) associated with controlled release of induction molecules to generate insulin-producing cells (IPCs). Based on physicochemical properties, AHA-PAAM inverted colloidal crystal scaffolds (ICCSs) at a 1:1 weight ratio of AHA to PAAM were used, modified with growth and differentiation factor 8, and grafted with CHIR99021-loaded solid lipid nanoparticles (CHIR99021-SLNs-GDF8-AHA-PAAM ICCSs) to differentiate iPSCs into definitive endoderm (DE) cells. Induction with fibroblast growth factor 7-grafted retinoic acid-loaded SLNs (FGF7-RA-SLNs) further differentiated DE cells into insulin-producing cells (IPCs) in the constructs. An introduction of sustained delivery facilitated bioavailability of CHIR99021 and RA during DE and islet formation, and yielded a high quantity of secreted insulin from IPCs after stimulation of glucose. Loaded CHIR99021 and grafted FGF7 acted as supporters to promote the main function of grafted GDF8 and loaded RA in DE and islet growth. From the highest expression of pancreatic and duodenal homeobox 1, we have reached the appropriate concentration of GDF8, CHIR99021, RA and FGF7 for regenerating IPCs. These data showed that the 2-stage guided differentiation of iPSCs into IPCs in CHIR99021-SLNs-GDF8-AHA-PAAM ICCSs can be promising in ameliorating insulin secretion by β-cell regeneration.