Can you tell us about your research?
Complex biological samples are routinely processed before they can be analysed in the lab, or used for therapeutic purposes in the clinic. This normally involves the initial step of centrifuging the cells and the use of antibody labelling technology to isolate desired cell types. Researching in the Bone Marrow Stem Cells and Cellular Therapies group, led by Prof. Stefan Scheding, I have been working on a microfluidic-based acoustophoresis method as a label-free approach of purifying cells from heterogeneous cell populations.
Acoustophoresis, which basically means migration with sound, can be used to separate cells based on their size, density and compressibility in relation to the media in which they are suspended. This allows for selective separation without the use of labelling, provided the acoustic properties of the target cells are sufficiently different from the non-target population. This is a particularly attractive method as it is simple, gentle, cost-effective and has no impact on cell function or survival.
I have been using microchips developed in the lab of my co-supervisor Prof. Thomas Laurell, into which cells enter through inlets, are subject to acoustic forces, and are then separated to specific outlets based on their intrinsic cell properties. The main acoustophysical property that I have been focused on is cell size. With this approach we have generated protocols to separate tumour cells from stem cell transplants, isolate mesenchymal stromal cells from bone marrow explants and purify stromal cells suitable for transplantation from heterogeneous cell cultures, among others.
The technology also allows us to perform a label free pre-enrichment step, before further purification steps of a desired target population. This can significantly reduce the time taken to attain a pure population and, in the case of FACS allows the application of a much-reduced antibody panel. I have also been involved in developing a method to predict optimal separation conditions, or to identify whether desired populations can be enriched by this technology or not.
In summary, the goal of my research has been to assess whether it is it feasible to use this method in a number of different contexts, all linked in some way to stem cells and the development of the method towards clinical application.
How did you end up in the Scheding group?
I studied for my Master’s degree at Berlin Institute of Technology and came to Lund as an exchange student in 2014. I began working in the Scheding group on an exciting project involving the separation of tumour cells from blood samples. Using the preliminary data I generated, we were able to get the funding for me to continue on to a PhD, during which I have been research at both Lund Stem Cell Center and the department of Biomedical Engineering at the Faculty of Engineering.
What are the most valuable things you have learned from doing a PhD?
During this time, I have learned what it means to be a researcher. This has involved being organised, learning about yourself and growing in experience. Sometimes you have to be resilient and just pushing through, even if it’s hard. There’s a lot of problem solving involved, so working things out and not being scared to ask for help, and keeping your sanity in the process!
What have you enjoyed the most about your PhD?
It’s great to be involved in new research and to take part in knowledge exchange and scientific discussions with motivated and skilled people. I was lucky enough to work with a lot of different projects, so I got a lot of great experience from this – learning methods, planning projects, collaborating with others. I also supervised a number of students, which was extremely rewarding. It’s great to feel you can pass on your knowledge to someone who can then independently create some meaningful data of their own.
What are your plans for after your defence?
First I will take some vacation days, but then I’ll be starting to work on a new project connected to the hospital. Here the focus will be to develop and evaluate cell therapies in different disease models.
Franziska will be defending her PhD thesis titled:
Label-free processing of stem cell preparations by acoustophoresis
Friday 12th June 2020 at 13:00 at Segerfalksalen BMC A10, Sölvegatan 17, Lund.
Zoom https://lu-se.zoom.us/j/61222729227
Her opponent is Associate Professor Daniel Irimia, Deputy Director of the BioMEMS Resource Center at the Center for Engineering in Medicine (CEM), Massachusetts General Hospital, Boston.