Tailoring extracellular matrix niches: Impact of glycosaminoglycan content on multiple differentiation of human mesenchymal stem cells
Xingxing Yang, Maitraee Mistry, Abigail Dee Chen, Barbara Pui Chan
Abstract
Glycosaminoglycan (GAG) represents an important extracellular matrix (ECM), particularly in GAG-rich tissues such as nucleus pulposus and cartilage. The ratio of GAGs/hydroxyproline (HYP) is an indicator of the relative abundance of the space-filling GAG matrix to the fibrous collagen matrix in a particular tissue. Here, we hypothesize that ECM niche with different GAG/HYP ratios will affect the outcomes of multiple differentiation of human mesenchymal stem cells (hMSCs). Specifically, we fabricated collagen-based biomaterials with different GAG/HYP ratios, and differentiate hMSCs in these materials towards osteogenic, chondrogenic and discogenic lineages. In osteogenic differentiation, Collagen without GAG (GAG/HYP ratio 0) showed higher calcium (Ca) and phosphorus (P) deposition and Ca/P ratio, more biomimetic ultrastructure, and better osteogenic phenotypic expression. For chondrogenic differentiation, aminated collagen (aCol-GAG) with intermediate GAG content (GAG/HYP ratio 5.0:1) showed higher GAG deposition, more biomimetic ultrastructure, and better chondrogenic phenotype. In discogenic differentiation, aminated collagen-aminated hyaluronic acid (aHA)-GAG (aCol-aHA-GAG) with the highest GAG content (GAG/HYP ratio 19.8:1), showed intensive GAG deposition, biomimetic ultrastructure, and higher phenotypic marker expression. This study contributes to developing collagen-based biomimetic materials with different GAG/HYP ratios and suggests the use of tissue-specific GAG/HYP ratio as a scaffold design parameter for hMSCs-based musculoskeletal tissue engineering. (198 words). • Successful fabrication of collagen-based scaffolds with controllable GAG/HYP ratios. • Demonstrated significance of biomimetic GAGs content in hMSCs multiple differentiation outcomes • Collagen-based scaffold without GAG facilitated osteogenic differentiation. • Collagen-based scaffold with intermediate cartilage-mimicking GAG content (GAG/HYP ratio 5:1) promoted chondrogenic differentiation. • Collagen-based scaffold with extremely high nucleus pulposus-mimicking GAG content (GAG/HYP ratio 19.8:1) enhanced discogenic differentiation.