Development of a device to stretch tissue-like materials and to measure their mechanical properties by scanning probe microscopy

Abstract

We developed a new stretch device to investigate the biomechanical responses to an external loading force on a tissue-like material consisting of cells and a collagen gel. Collagen gel, a typical matrix found abundantly in the connective tissue, was attached to an elastic chamber that was precoated with a thin layer of collagen. Madin-Darby canine kidney (MDCK) cells that were cultured on the collagen gel were stretched in a uniaxial direction via deformation of the elastic chamber. Changes in the morphology and stiffness of the tissue-like structure were measured before and after the stretch by using wide-range scanning probe microscopy (WR-SPM). The change in cellular morphology was heterogeneous, and there was a 2-fold increase in the intercellular junction due to the stretch. In addition to the SPM measurements, this device enables observation of the spatial distribution of cytoskeletal proteins such as vimentin and α-catenin by using immunofluorescent microscopy. We concluded that the stretch device we have reported in this paper is useful to measure the mechanical response of a tissue-like material over a range of cell sizes when exposed to an external loading force.

A polymeric cell stretching device for real-time imaging with optical microscopy

“…A common approach is using gel construct for cyclic stretching (Vanderploeg et al 2008) where cells were seeded into liquid fibrin hydrogel conditioned with culture solution. Mechanical pulling using stepper motors or controllable linear stages was the common actuation technique (Lindqvist et al 2010, Pfister et al 2004, Mizutani et al 2007, Nguyen et al 2012. Stretching can be achieved wirelessly using magnetically actuated microposts (Sniadecki et al 2008).…”

Long-term Culture of Human iPS Cell-derived Telencephalic Neuron Aggregates on Collagen Gel

“…We suggest two possible reasons for these results. First, the human iPS cell-derived telencephalic neuron aggregates are fragile and are thus suitable for culture on collagen gel, which is softer than the collagen or PDL/laminin/fibronectin coating (Yunoki et al, 2011, Mizutani et al, 2007. Alternatively, the cellular crawling into the 3D-pore structure in the collagen gel contributed to the tight adhesiveness between these aggregates and the collagen gel.…”

Tempo-Spatial Change of Cellular Stiffness and Geometry in the Process of Developing Epithelial Cell–Cell Adhesion Measured by Atomic Force Microscopy

“…Our group modified a commercial AFM to wide-range scanning probe microscopy (WR-SPM) which enabled acquisition of elasticity and topography distribution of thick sample like epithelial tissue over sub-millimeter scan range [5]. By using the AFM or WR-SPM, some research groups showed that cell-cell boundaries are stiffer than the center of the cells [4,6]. In the present study, we measured a time course of topography and elasticity distribution of epithelial cells during regenerating cell-cell adhesion using WR-SPM.…”