Measurement of the initial Young's modulus for vascular endothelial cells by atomic force microscopy

摘要

The initial Young's modulus of human umbilical vein endothelial cells (HUVECs) in a medium was studied at ca. 25(deg)C by atomic force microscopy (AFM). For the purpose of obtaining the numeral, the elasticity of 10 wt% gelatin gel was determined from stress-strain curves measured with a tensile tester. The AFM measurement of the gelatin gel was carried out in liquid, and then the cross-sectional area of 10 wt% gelatin gel in contact with a tip of the cantilever was estimated, assuming that the relation between force and the initial displacement holds Hook's law. It was considered to be identical to that of vascular endothelial cells. Thus, Young's modulus of HUVECs was estimated to be 2.2 x 105 Pa at a position proximal to the nucleus, while it was estimated to be 1.6 x 105 Pa at a distal position close to lamellipodia. That is, the stiffness around a nucleus appeared to be higher than that in the distal region far from a nucleus. The measurements of the elasticity of vascular endothelial cells were concluded to be in good agreement or slightly higher compared with the values reported for cells.