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Soft Mattter and Biophysics seminar-Stefano Pagliara University of Exeter

Single-particle and Single-Cell Microfluidic Manipulation and Analysis

Micro- and nano-scale bioengineering technologies are becoming pivotal in biological and health sciences. In this talk I will illustrate how microfluidics, optical trapping and imaging can be combined to investigate fundamental biological processes such as membrane transport, stem cell differentiation and antibiotic tolerance.

In the first part of my talk I will introduce a synthetic model system to mimic molecular diffusion based on colloidal particles, microfluidics, optical tweezers and particle tracking. By using this platform, I have demonstrated that particle diffusion in a closely confining channel is both hindered and anisotropic [1,2]; there is an optimal interaction strength between the transported particle and the transporter channel [3-5]; hydrodynamic particle-particle interactions are distance independent in a narrow channel [6].

In the second part of my talk I will introduce a novel microfluidics-microscopy platform that I have employed to mechanically phenotype live mammalian cells including embryonic stem cells (Fig. 1).

I will show that the nuclei of some embryonic stem cells display a unique material property that is they are auxetic; exhibiting a cross-sectional expansion when stretched and a cross-sectional contraction when compressed [7].

In the third part of my talk I will present a novel approach, based on microfluidics and time-lapse imaging, for simultaneously investigating the physiological response to drugs of thousands individual bacteria, including rare antibiotic tolerant phenotypes [8].

Text Box:  Text Box: 20 µmText Box: 10 µmText Box: 25 µmFIG. 1. Schematics illustrating mechanical phenotyping of single live embryonic stem cells.

References

  1. S. L. Dettmer, S. Pagliara, K. Misiunas, U. F. Keyser, Physical Review E 89, 062305 (2014).

  2. S. L. Dettmer, U. F. Keyser, S. Pagliara, Review of Scientific Instruments 85, 023708 (2014).

  3. S. Pagliara, C. Schwall, U. F. Keyser, Advanced Materials 25, 844 (2013).

  4. S. Pagliara, S. L. Dettmer, U. F. Keyser, Physical Review Letters 113, 048102 (2014).

  5. Y. Tan, J. Gladrow, U. F. Keyser, L. Dagdug, S Pagliara, Physical Review E 96, 052401 (2017).

  6. K. Misiunas, S. Pagliara, E. Lauga, J. R. Lister, U. F. Keyser, Physical Review Letters 113, 048102 (2014).

  7. S. Pagliara et al., Nature Materials 13, 638 (2014).

  8. R. Bamford, A. Smith, J. Metz, G. Glover, R. W. Titball, S. Pagliara, BMC Biology 15, 121 (2017).