Development of a pro‐angiogenic stem cell‐derived vascular cell extracellular matrix‐decorated hyaluronic acid hydrogel

Abstract

Diabetic foot ulcers (DFU) are debilitating chronic wounds which affect up to a third of diabetic patients. Due to the underlying diabetic pathophysiology, normal wound healing is perturbed. In particular, there is insufficient re‐vascularisation of the wound bed, ultimately leading to the development of chronic wounds. Current treatment protocols are insufficient to stimulate re‐vascularisation and wound closure, ultimately leading to ~20% of patients with a DFU requiring lower limb amputation. Extracellular matrix (ECM)‐derived biomaterials have demonstrated great promise to promote tissue vascularisation and wound repair. In the present study, the overarching goal was to develop a decellularised ECM from human induced pluripotent stem cell (hiPSC)‐derived vascular cells, and incorporate it into a hyaluronic acid‐based hydrogel for wound healing. Vascular differentiation of hiPSCs yielded a heterogenous population containing both CD31 expressing endothelial cells (iEC), and CD31‐negative stromal cells (iSC). ECM deposition by iSCs was stimulated by treatment with ascorbic acid and macromolecular crowder carrageenan. Post‐decellularisation, the ECM composition was analysed by immunofluorescent and histological staining, indicating the presence of ECM components such as fibronectin, fibrillar collagens, perlecan and glycosaminoglycans, all having implications in angiogenic processes. Decellularised ECM accelerated the capacity of iECs to form tube‐like structures when added to cell culture media in 2D. Decoration of hyaluronic acid (HyA)‐based hydrogels with this decellularised ECM enhanced metabolic activity and attachment of both HUVECs and human dermal fibroblasts seeded on these hydrogels. Taken together, this ECM‐decorated HyA‐based hydrogel has the potential to enhance angiogenesis and revascularisation in chronic wound applications such as DFU.