JSMEC : Vol. 45 (2002) , No. 4 Special Issue on Bioengineering pp.870-879

Tensile Properties of Contractile and Synthetic Vascular Smooth Muscle Cells

Hiroshi MIYAZAKI¹⁾, Yoshitaka HASEGAWA²⁾ and Kozaburo HAYASHI¹⁾

1) Division of Mechanical Science, Department of Systems and Human Science, Graduate School of Engineering Science, Osaka University
2) Advanced Technology R&D Center, Mitsubishi Electric Corporation

(Received May 31, 2002)

Tensile properties of vascular smooth muscle cells (VSMCs) of synthetic and contractile phenotypes were determined using a newly developed tensile test system. Synthetic and contractile VSMCs were isolated from the rabbit thoracic aorta with an explant and an enzymatic digestion method, respectively. Each cell floated in Hanks' balanced salt solution of 37°C was attached to the fine tips of a pair of micropipettes with a cell adhesive and, then, stretched at the rate of 6µm/sec by moving one of the micropipettes with a linear actuator. Load applied to the cell was measured with a cantilever-type load cell; its elongation was determined from the distance between the micropipette tips using a video dimension analyzer. The synthetic and contractile VSMCs were not broken even at the tensile force of 2.4µN and 3.4µN, respectively. Their stiffness was significantly higher in contractile phenotype (0.17N/m) than in synthetic one (0.09N/m). The different tensile properties between synthetic and contractile cells are attributable to the differences in cytoskeletal structures and contractile apparatus.

Key Words:

Biomechanics, Measurement, Vascular Smooth Muscle Cell, Phenotype, Tensile Testing, Stiffness, Cellular Mechanics