Effect of Hydrogel Matrix and Fluid Shear Stress on the Behavioral Regulation of Mesenchymal Stem Cells

Development of a micromodel that recapitulates multiple mechanical properties to mimic the complex mechanical microenvironment is crucial for cell-based research. Herein, a microsystem combining structure of hydrogel matrix and acoustic streaming (AS) to mimic the cellular microenvironment is proposed, which can realize multiplex cellular mechanical cues, including matrix stiffness, fluid shear stress (FSS) generated by AS, and matrix roughness. The results demonstrate that the cell spreading area enlarges with the increase of matrix stiffness, and cell spreading is encouraged by integrin beta 1 cluster to polymerize actin when combines the hydrogel matrix with FSS. In addition, FSS has the influence on the roughness of the hydrogel, which further affects the cell morphology and mechanical properties, inducing mesenchymal stem cells (MSCs) differentiation into astrocytes rapidly. Meanwhile, cell migration is also enhanced by FSS stimulation, particularly, undifferentiated cells at 22 kPa hydrogel have the fastest migration speed, and change the movement model from contact inhibition to contact stimulation migration. Especially, matrix roughness and stiffness dominantly control of cell spreading and differentiation, whereas FSS affects cell migration. In conclusion, the microsystem in this work shows superior performance in regulating the spreading, differentiation, and migration of MSCs, which provides a new tool for cell-microenvironment study. In order to mimic the microenvironment of mesenchymal stem cells growth in vivo, herein, a microsystem is proposed that combines hydrogel matrix with gigahertz acoustic streaming, which can realize the regulation of cell behaviors by three mechanical factors of matrix stiffness, fluid shear stress, and matrix roughness.image (c) 2024 WILEY-VCH GmbH