Engineering a microcarrier based on a polysaccharide-growth factor complex for enhancing the proliferation of mesenchymal stem cells

Mesenchymal stem cell (MSC) delivery has been broadly investigated as a cell-based therapy strategy towards various diseases and tissue injury. In these applications, the cell-delivery vehicle plays a crucial role in determining the therapeutic performance of MSCs and their fate post-implantation. We report here the development of a microcarrier system combining platelet-derived growth factor-BB (PDGF-BB) and a PDGF-BB-binding polysaccharide - Eucommia ulmoides (EUP3) - for MSC cultivation. First, we investigated the optimal conditions to prepare the EUP3-PDGF-BB complex, by comparing its i) diameter, ii) morphology, and iii) bioactivity to promote MSC proliferation and fibroblast migration in vitro, under different PDGF-BB/EUP3 ratios. Then, we fabricated microspheres using gelatin and EUP3 as the matrixwhile stabilizing PDGF-BB at the optimal ratio for MSC adhesion and growth. Live staining and SEM observation indicated that the prepared microspheric carrier supported MSC growth and maintained cell stemness. We suggest that the EUP3/PDGF-gelatin microcarriers can potentially serve as a cell-delivery vehicle for tissue engineering. (C) 2019 Elsevier B.V. All rights reserved.