Controllable actuation of photomechanical bilayer nanocomposites for in vitro cell manipulation

Mechanotransduction enables cells to translate external forces and physical constraints into biochemical signals controlling multiple aspects of cell behavior. Methodologies mimicking various mechanical and biomedical forces exposed to cells, have been proposed to investigate cell mechanotransduction. However, it is still a great challenge developing platform towards dynamically multivariate mechanical stimulation addressing individual cells or small colonies of cells. A photomechanical and biocompatible platform for extracellular mechanical stimuli is constructed by soft bilayer nanocomposites composed of polydimethylsiloxane (PDMS) and PDMS/GNPs (graphene nanoplatelets). The fast backlash bending process can give rise to mechanical stimuli to the cells growing on it in a controllable manner by near infrared (nIR) irradiation. Beneficial from the excellent controllability in nIR light intensity and working frequency, the backlash bending velocity, acceleration, frequency, as well as sophisticated bending process can be well controlled, thus extracellular mechanical forces even predesigned loading cycles can be realized. SGC-7901 cells viability, one of the lines in highest incidence Gastric cancer in almost Asian countries, can be restricted by our proposed platform. It will not only provide a solution for studying cell mechanotransduction with more complicated force conditions, but also demonstrate a promising methodology supplementing the physical therapy for fighting against the malignant tumor. (C) 2018 Elsevier Ltd. All rights reserved.