Effects of Matrix Stiffness on the Morphology, Adhesion, Proliferation and Osteogenic Differentiation of Mesenchymal Stem Cells

Abstract

BMMSCs have drawn great interest in tissue engineering and regenerative medicine attributable to their multi-lineage differentiation capacity. Increasing evidence has shown that the mechanical stiffness of extracellular matrix is a critical determinant for stem cell behaviors. However, it remains unknown how matrix stiffness influences MSCs commitment with changes in cell morphology, adhesion, proliferation, self-renewal and differentiation. We employed fibronectin coated polyacrylamide hydrogels with variable stiffnesses ranging from 13 to 68 kPa to modulate the mechanical environment of BMMSCs and found that the morphology and adhesion of BMMSCs were highly dependent on mechanical stiffness. Cells became more spread and more adhesive on substrates of higher stiffness. Similarly, the proliferation of BMMSCs increased as stiffness increased. Sox2 expression was lower during 4h to 1 week on the 13-16 kPa and 62-68 kPa, in contrast, it was higher during 4h to 1 week on the 48-53 kPa. Oct4 expression on 13-16 kPa was higher than 48-53 kPa at 4h, and it has no significant differences at other time point among three different stiffness groups. On 62-68 kPa, BMMSCs were able to be induced toward osteogenic phenotype and generated a markedly high level of RUNX2, ALP, and Osteopontin. The cells exhibited a polygonal morphology and larger spreading area. These results suggest that matrix stiffness modulates commitment of BMMSCs. Our findings may eventually aid in the development of novel, effective biomaterials for the applications in tissue engineering.

Stromal-Cell-Derived Factor (SDF) 1-Alpha Overexpression Promotes Bone Regeneration by Osteogenesis and Angiogenesis in Osteonecrosis of the Femoral Head

“…Runx2 is essential in BMSC differentiation [51]. In the present study, we discovered that the expression of Runx2 was decreased post-MP treatment, whereas it was upregulated after the transplantation of SDF-1α-GFP-BMSCs, which is consistent with the results of previous studies [52, 53].…”

Effect of matrix stiffness and adhesion ligand density on chondrogenic differentiation of mesenchymal stem cells

“…This was similar to the studies that the morphology and adhesion of BMSCs were highly dependent on mechanical stiffness (Sun et al, 2018). This was similar to the studies that the morphology and adhesion of BMSCs were highly dependent on mechanical stiffness (Sun et al, 2018).…”

Dimensionality changes actin network through lamin A and C and zyxin

“…[16] On stiffer materials and with more cellular tension human mesenchymal stromal cells (hMSCs) show increased osteogenic differentiation, while softer materials and lower cellular tension enhance differentiation to chondro-and adipogenic lineages. [17][18][19][20][21] These changes in hMSC differentiation have been shown to be orchestrated by actin stress fibers [22] , focal adhesions [22] , lamin A and C [23] and Yes-associated protein 1 (YAP1). [24,25] While other material properties are relatively well studied, the dimensionality (2D v. 3D) of a material has not yet been widely studied.…”