Elise Aeby wins award for best master’s thesis in nanoscience 2016

Elise Aeby’s design for a new microfluidic platform to study tissue cells has earned her this year’s award for the best master’s thesis in nanoscience at the University of Basel. The young researcher looks back on a fulfilling time in Basel in which she learnt a great deal and played an active role in various SNI activities promoting the nanosciences. She began her doctorate at ETH Zurich in May.

Insights from hanging drops
For the award-winning thesis, Elise Aeby developed a microfluidic platform designed to overcome certain limitations in an earlier model, working in the group led by Dr Andreas Hierlemann of the ETH Zurich Department of Biosystems Science and Engineering in Basel. The existing platform can be used to create microtissues that are excellently suited to studying communication between different tissue types and the effect of drugs. Cells from a cell culture are first of all suspended in a nutrient solution, and then arranged in a structure known as a hanging drop network to form a microtissue. The drops are held together by the solution’s surface tension. The cells inside this three-dimensional microtissue – also known as a spheroid – are able to communicate with each other, and behave in a similar fashion to natural tissue. Thanks to a microfluidic system consisting of minute channels, the cells in the hanging drops can be brought into contact with spheroids in a different tissue, and with active substances. The resulting effects on the different microtissues can be observed using a microscope or by analyzing the nutrient solution. Further information is obtained by examining the microtissue at the end of the experiment.

The platform developed in Hierlemann’s laboratory has the advantage of closely mirroring conditions in the human body, in contrast to two-dimensional propagation in a culture dish. However, the open system is sensitive, and depends on specific computer programs. What is more, the movement of the hanging drops prevents tracking of specific cells within the microtissue, or the use of confocal microscopes.

Tweaking the platform
For her master’s thesis, Elise Aeby converted this platform to a half-closed system, which is more robust and provides better images for evaluation of the results. She achieved this by “packaging” the spheroids in hydrogel, limiting their mobility without restricting the exchange of nutrients, waste products or oxygen. The platform is made from polydimethylsiloxane (PDMS), in which tiny channels and culture chambers are molded using soft lithography. These channels and chambers are open, and can be easily filled by researchers. In order to reversibly seal the structures, Aeby attached a thin glass plate to the PDMS platform using a vacuum line.

“The platform works really well,” remarks Elise Aeby. “The images we can now capture with a confocal microscope are significantly better, and provide much more information.”

“The new platform combines microfluidic 3D tissue culture with high-resolution microscopy in a very robust manner, enabling us to take long-term measurements over periods of more than 10 days which would not have been possible using the previous system,” confirms Dr Olivier Frey, her supervisor and formerly a senior researcher in Hierlemann’s team. The platform has since been used by a doctoral candidate from another research group to study communication between different tissue cell types. Other researchers in the team are also starting to use the new system.

Doctoral dissertation at ETH Zurich
Elise Aeby found her work with cell cultures so fascinating and motivating that she had originally chosen tissue engineering as the focus of her doctoral thesis. Accordingly, she applied for positions including one in the group led by Professor Dr Viola Vogel at ETH Zurich. The team, which works in the field of applied mechanobiology, was immediately taken with the young nanoresearcher from Basel, and suggested she write her doctoral dissertation on a project funded by the CTI (Commission for Technology and Innovation). Even though this meant a departure from the topic of tissue engineering, Elise was instantly drawn to the idea, and turned down her other offers. “This project is about the application of a newly developed device able to guide a tiny robot using eight electromagnets with five different degrees of freedom.” The apparatus, dubbed NanoMag, was developed by an ETHZ spin-off company, and will be the focus of Elise Aeby’s doctoral dissertation that she started in May 2017.

Fond memories of the nanoscience program
As a result, Aeby’s time as a nanoscience student in Basel is finally at an end. She looks back on the course as a deeply fulfilling experience, and is happy she chose to study nanosciences back in 2010. She first acquired a taste for nanotechnology while writing her Matura thesis on artificial muscles. Each block course, each assignment, and ultimately her master’s thesis strengthened her conviction that she had chosen the right path. “The nano study program wasn’t easy,” she recalls. “But we always had a great team spirit, and we supported and helped each other.” Her positive experiences and enthusiasm meant the young researcher was always happy to help out with various SNI activities and act as an ambassador for the nanoscience program. Besides appearing in SNI videos, Elise Aeby spoke to numerous future nanosciences students at open days, served on the INASCON 2015 organizing committee, and supported the SNI stand at events such as tunBasel.

We would like to thank Elise for the excellent collaboration during her time at the SNI, and congratulate her on her best master’s thesis award. We wish her every success in the future.