[Spatial Constraints of Rectangular Hydrogel Microgrooves Regulate the Morphology and Arrangement of Human Umbilical Vein Endothelial Cells].

Objective: To construct microscale rectangular hydrogel grooves and to investigate the morphology and alignment of human umbilical vein endothelial cells (HUVECs) under spatial constraints. Vascular endothelial cell morphology and alignment are important factors in vascular development and the maintenance of homeostasis. Methods: A 4-arm polyethylene glycol-acrylate (PEG-acrylate) hydrogel was used to fabricate rectangular microgrooves of the widths of 60 μm, 100 μm, and 140 μm. The sizes and the fibronectin (FN) adhesion of these hydrogel microgrooves were measured. HUVECs were seeded onto the FN-coated microgrooves, while the flat surface without micropatterns was used as the control. After 48 hours of incubation, the morphology and orientation of the cells were examined. The cytoskeleton was labelled with phalloidine and the orientation of the cytoskeleton in the hydrogel microgrooves was observed by laser confocal microscopy. Results: The hydrogel microgrooves constructed exhibited uniform and well-defined morphology, a complete structure, and clear edges, with the width deviation being less than 3.5%. The depth differences between the hydrogel microgrooves of different widths were small and the FN adhesion is uniform, providing a micro-patterned growth interface for cells. In the control group, the cells were arranged haphazardly in random orientations and the cell orientation angle was (46.9±1.8)°. In contrast, the cell orientation angle in the hydrogel microgrooves was significantly reduced ( Conclusion: Hydrogel microgrooves can regulate the morphology and orientation of HUVECs and mimic to a certain extent the