Design and development of multiaxial/hierarchical system for the study of cell-matrix mechanics

Brett J Bell, Purdue University

Abstract

The importance of mechanical cues in guiding cell function and stem cell fate is now widely accepted; however a gap in knowledge of how these cues are transferred from tissue levels to resident cells remains. The objective of this dissertation was to create and test a multiaxial mechanical testing system for hierarchical analysis of biomechanical processes. The design of this system was driven by the desire to create a reliable and convenient method of applying tissue level mechanical perturbation while simultaneously measuring responses across multiple hierarchical levels (tissue, extracellular, intracellular). To make the system as complete as possible specimen boundary conditions were optimized in addition to user interface, mechanical actuation and, environmental control subsystems. To demonstrate the utility of the device, strains were quantified on macro, meso, collagen fibril and intracellular levels. Results of this study showed that strains perpendicular to the cell major axis are highly amplified on cell levels in comparison to those on larger length scales. This amplification of intracellular and especially nuclear strains may have important implications in terms of presentation and availability of specific genes for transcription activities. Finally, this work established an important framework for future studies involving the specific mechanisms of mechanotransduction in a 3D fibrilar context.

Degree

Ph.D.

Advisors

Voytik-Harbin, Purdue University.

Subject Area

Cellular biology|Biomedical engineering|Biomechanics

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