713 単離ストレスファイバの引張特性と局所ひずみ分布(S07-2 マイクロ・ナノバイオメカニクス(2),S07 マイクロ・ナノバイオメカニクス)

Abstract

In our previous study, tensile properties of single stress fibers (SF) chemically isolated from vascular smooth muscle cells have been investigated. Tensile tests were performed at a single strain rate of 0.02s^<-1>. In this study, the strain rate dependency of tensile properties of SF was investigated. The results showed that averaged force-strain relationships were found to be almost linear in the physio-logical strain range of 0.0-0.4 for 0.01s^<-1> and 0.05s^<-1>. In contrast, the force-strain relationship was nonlinear for the 0.1s^<-1> strain rate. The reason for this difference is unclear, however possibly due to a presence of threshold in strain rate between 0.01s^<-1> and 0.1s^<-1>. Moreover, microstructural canges of SF during stretching were investigated using a speckle fluorescent microscopy technique. SF were labeled using Quantum Dot in dotted pattern to analyze local strain in SF. The results showed that local stretch ratio was nonuniformly distributed through the length of the SF. This approach may provide further insights to SF biomechanics.