Programmable cell stretcher

• Main Author: Huang, Yuli.
• Other Authors: Nguyen Nam-Trung
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/51145
• Institution: Nanyang Technological University

In the recent decades, it has become widely known that the physiological changes in cells can be induced by various mechanical stimuli. The study of mechanobiology is established at the end of the last century to investigate the cell response to mechanical stimulus. Detailed understanding of this causality enables the discovery of new mechanical-based therapies and new drugs that specially targets at the mechanotransduction signalling pathways. Driven by this vast biomedical potential, various mechanisms with the capability of applying different types of physical stimulus to cells in vitro have emerged. One of the most popularly studied stimuli is cyclic tensile strain, which exists ubiquitously in human native tissues and is proven to have up-regulatory effects to most of the cell activities. In this report, the systematic development and commissioning of a high throughput cell-stretching device based on a novel stretching mechanism is reported. The microfluidic device enables the minimal consumption of sample cells and reagents. At the meantime, the footprint of each unit is less than 0.64 cm2, and the actuation of its 24 valves is individually programmable. These factors have enabled the device to obtain a high degree of parallelization. More importantly, as the mechanism allows the cells to be stretched within the microscopic focal plane, and the device can be configured to have an ultra-thin bottom, it brings the real-time imaging capability to the level of subcellular cytoskeleton details. II By embedding fluorescent micro-beads in the membrane, this device enables the in-situ measurement of strain. This technique is used for mechanical characterisation of the device, where the cross-correlation algorithm is applied to find the qualitative deformation and the manual bead tracking is used for quantification of the deformation. Both techniques have confirmed the simulation result, which predicts that the device possess the desired characteristics such as strain uniformity and input-output linear proportionality. Numerous cell tests have been carried out in the device, from which the proper cell culturing protocol is established, the capability of strain transferrable and making high optical resolution real-time imaging is confirmed.