title: Design and construction of an equibiaxial cell stretching system that is improved for biochemical analysis.
abstract: We describe the design and validation of an equibiaxial stretching device in which cells are confined to regions of homogeneous strain. Using this device, we seek to overcome a significant limitation of existing equibiaxial stretching devices, in which strains are not homogeneous over the entire region of cell culture. We cast PDMS in a mold to produce a membrane with a cylindrical wall incorporated in the center, which was used to confine cell monolayers to the central membrane region subjected to homogeneous equibiaxial strain. We demonstrated that the presence of the wall to hold the culture medium did not affect strain homogeneity over the majority of the culture surface and also showed that cells adhered well onto the PDMS membranes. We used our device in cyclic strain experiments and demonstrated strain-dependent changes in extracellular signal-regulated kinase (ERK) and tyrosine phosphorylation upon cell stretching. Furthermore, we examined cell responses to very small magnitudes of strain ranging from 1% to 6% and were able to observe a graduated increase in ERK phosphorylation in response to these strains. Collectively, we were able to study cellular biochemical response with a high degree of accuracy and sensitivity to fine changes in substrate strain. Because we have designed our device along the lines of existing equibiaxial stretching technologies, we believe that our innovations can be incorporated into existing systems. This device would provide a useful addition to the set of tools applied for in vitro studies of cell mechanobiology.
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore.
authors.forename: Chaitanya Prashant
authors.initials: CP
authors.lastname: Ursekar
authors.affiliation: Institute of High Performance Computing, Agency for Science, Technology and Research, Singapore.
authors.forename: Soo-Kng
authors.initials: SK
authors.lastname: Teo
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hirata
authors.affiliation: Laboratory for Mechanical Medicine, Locomotive Syndrome Research Institute, Nadogaya Hospital, Kashiwa, Chiba, Japan; Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Harada
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore; Bioinformatics Institute, Agency for Science, Technology and Research, Singapore.
authors.forename: Keng-Hwee
authors.initials: KH
authors.lastname: Chiam
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore; Laboratory for Mechanical Medicine, Locomotive Syndrome Research Institute, Nadogaya Hospital, Kashiwa, Chiba, Japan; Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sawada
mesh_terms: D000465:Algorithms; D000535:Aluminum; D000818:Animals; D016880:Anisotropy; D001672:Biocompatible Materials; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry; D003584:Cytological Techniques / Q000295:instrumentation*; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D020342:Finite Element Analysis; D057809:HEK293 Cells; D006801:Humans; D008422:Materials Testing; D008567:Membranes, Artificial; D051379:Mice; D010766:Phosphorylation; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D014443:Tyrosine / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; D014443:Tyrosine; C013830:baysilon; D003094:Collagen; D000535:Aluminum; D048049:Extracellular Signal-Regulated MAP Kinases