ISBN 9783843916622

978-3-8439-1662-2, Reihe Apparatedesign

Ya-Yu Chiang
Development of a Microfluidic Switching Platform for the Temporal Investigation of Membrane Receptor Signal Transductions

160 Seiten, Dissertation Technische Universität Dortmund (2014), Softcover, A5

Zusammenfassung / Abstract

Systems biology promises to deliver a holistic time and space understanding of biological processes with applications including the identification of new therapeutic targets as well as prognostic and diagnostic markers. To support this endeavour, the research for my Ph.D. thesis has focused on the development and application of novel techniques which can probe whole cell systems within sub-second timescales.

A whole cell microfluidic quenched flow analysis system which involves a two-step deterministic lateral displacement (DLD) arrangement based on a pinched-flow approach using so-called stream-thinning elements (STEs) was developed. In place of conventional (micro)mixing, the cells can instead be rapidly switched between biochemical microenvironments. Millisecond switching was used to stimulate and preserve molecular transitions involved in key cell surface processes. Presented in chapter 2, the research involved the development of microfluidic quenched flow analysis concept and system design. Chapter 3 discusses the system's speed limit, measuring the chemical switch time and analysis of micromixing driven by a cell roll−slip phenomena. Chapter 4 describes characterization of the incubation precision and methods to reduce the temporal variation. The final research chapter, chapter 5, documents results from the analysis of type I insulin-like growth factor receptor (IGF-1R) autophosphorylation state-switching and the biphasic epidermal growth factor receptor (EGFR) signal transduction mechanism.

In summary, this thesis has demonstrated the microfluidic technology is a valuable addition to the cell biology toolkit. The whole cell quenched flow platform can be used to peer within the 10–1000 ms window to gain new insights into the mechanisms underlying ligand-cell interactions. The millisecond temporal resolution of the microfluidic cell switching technology can be further harnessed for the deeper investigation of a tremendous spectrum of other cell surface processes.