EPFL BioE Talks SERIES "Time Resolved Scanning Ion Conductance Microscopy: Taking a Gentle Peek at Cell Surface Dynamics"


Event details

Date 29.03.2021 16:3017:00  
Speaker Prof. Georg Fantner, Institute of Biongineering and Institute of Microengineering, EPFL, Lausanne (CH)
Location Online
Category Conferences - Seminars

(note that this talk is number two of a double-feature seminar - see details of the first talk here)

The evolution of the 3D morphology of cells is at the heart of many biologically relevant process ranging from stem-cell differentiation, to cancer metastasis. Things become even more interesting when looking at the evolution of systems comprising the interaction of multiple cells such as the growth of organoids, the formation of networks by neurons or the infection of cells by pathogens. When studying these systems, the information we are after is not just in their static structure, but in how this structure changes over time. Time resolved imaging has proven to be an invaluable tool in this regard. While many excellent optical microscopy techniques exist for time resolved imaging in the sub-micrometer scale at both 2D and 3D, the options for 3D time lapse characterization at the nanometer scale are very limited. Atomic force microscopy has long since promised a solution but has failed to deliver except for cases of relatively sturdy cells such as bacteria1,2 or yeast.

Scanning ion conductance microscopy (SICM) on the other hand has been developed specifically for imaging of fragile surfaces of eukaryotic cells3. This true non-contact technique is ideally suited for label-free imaging of cell surfaces and achieves exquisite resolution down to the nanometer regime4,5. The challenge to harness this technique for time resolved 3D nanocharacterization of living cells lies in the relatively slow imaging speed of SICM. In this presentation I will show how we apply what we have learned from high-speed AFM to the field of SICM. By reengineering the SICM microscope from the ground up, we were able to reduce the image acquisition time for SICM images to 0.5s while extending the imaging duration to days. I will also discuss the combination of 3D surface data from SICM with 2D and 3D volume data from SOFI imaging for correlative high resolution imaging of the cell interior as well as the cell membrane6.

1. Eskandarian, H. A. et al. Division site selection linked to inherited cell surface wave troughs in mycobacteria. Nat. Microbiol. 2, 17094 (2017).
2. Odermatt, P. D. et al. Overlapping and essential roles for molecular and mechanical mechanisms in mycobacterial cell division. Nature Physics (2019) doi:10.1038/s41567-019-0679-1.
3. Hansma, P. K., Drake, B., Marti, O., Gould, S. A. & Prater, C. B. The scanning ion-conductance microscope. Science (80-. ). 243, 641–643 (1989).
4. Novak, P. et al. Nanoscale live-cell imaging using hopping probe ion conductance microscopy. Nat. Methods 6, 279–281 (2009).
5. Korchev, Y. E., Bashford, C. L., Milovanovic, M., Vodyanoy, I. & Lab, M. J. Scanning ion conductance microscopy of living cells. Biophys. J. 73, 653–658 (1997).
6. Navikas, V. et al. Correlative 3D microscopy of single cells using super-resolution and scanning ion-conductance microscopy. bioRxiv (2020) doi:10.1101/2020.11.09.374157.

GEORG E. FANTNER received his MS degree from the University of Technology Graz in 2003, and his PhD degree from UC Santa Barbara in 2006 (advisor: Paul K. Hansma). During his masters and PhD, he developed a number of high performance AFM instruments and applied them to the study of the molecular origin of bone fracture toughness. After a Postdoc in the biomolecular materials lab at the Massachusetts Institute of Technology (Advisor: Angela M. Belcher), he joined the École Polytechnique Fédéral de Lausanne as assistant professor in 2010. Now, as associate professor, he leads the laboratory for bio- and nano-instrumentation in the institute for bioengineering. His research, which has been funded by the European Research Council with an ERC starting grant and an ERC consolidator grant, focusses on the development of new technologies to measure and manipulate nanoscale structures in general, and the development of atomic force microscopy instrumentation in particular. He applies these instruments to answer questions in a variety of fields ranging from materials science and nanotechnology to biology and life science. His interdisciplinary work has been published in many high impact journals such as Nature Materials, Nature Nanotechnology, Nature Cell biology, Nature Microbiology, Nature Communications, Nano Letters, and Science, as well as featured in a number of popular science- and general-interest magazines. He serves as scanning probe microscopy editor for Microscopy and Microanalysis (CambridgeCore), and as editorial board member for Scientific Reports. His recent work focusses on the development of time resolved scanning probe microscopy imaging, encompassing new modes for high-speed AFM imaging of molecular processes, as well as long-term time lapse imaging of cellular processes usomg AFM and scanning ion conductance microscopy. Prof. Fantner hold several patents in the field of nanotechnology and is the co-founder of two nanotechnology companies. Recently he has become active in the field of open hardware, where he explores new avenues to foster free academic exchange of knowledge, particularly for the development of highly sophisticated custom instruments.

Zoom link (with registration) for attending remotely: https://go.epfl.ch/EPFLBioETalks

IMPORTANT NOTICE: due to restrictions resulting from the ongoing Covid-19 pandemic, this seminar can be followed via Zoom web-streaming only, (following prior one-time registration through the link above).

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