Actin Stress Fibers Response and Adaptation under Stretch

Abstract

One of the many effects of soft tissues under mechanical solicitation in the cellular damage produced by highly localized strain. Here, we study the response of peripheral stress fibers (SFs) to external stretch in mammalian cells, plated onto deformable micropatterned substrates. A local fluorescence analysis reveals that an adaptation response is observed at the vicinity of the focal adhesion sites (FAs) due to its mechanosensor function. The response depends on the type of mechanical stress, from a Maxwell-type material in compression to a complex scenario in extension, where a mechanotransduction and a self-healing process takes place in order to prevent the induced severing of the SF. A model is proposed to take into account the effect of the applied stretch on the mechanics of the SF, from which relevant parameters of the healing process are obtained. In contrast, the repair of the actin bundle occurs at the weak point of the SF and depends on the amount of applied strain. As a result, the SFs display strain-softening features due to the incorporation of new actin material into the bundle. In contrast, the response under compression shows a reorganization with a constant actin material suggesting a gliding process of the SFs by the myosin II motors.

The importance of structure property relationship for the designing of biomaterials using liquid crystal elastomers

“…84 Thus efforts are concentrated on studying how cells respond to mechanical stimuli so materials can be made to limit potential or irreversible cell damage. 85–87 When preparing materials, Younes et al confirmed the effects of crosslinking density of biocompatible polycaprolactone based star-copolymer elastomer and the stress of the material. 50 We reported that with the incorporation of the LC pendants, the liquid crystalline character of the LCE made it more resistant to strain, however it was still able to mimic the properties of tissue elasticity.…”