The development of 3D cell cultures is creating new opportunities for drug development, disease models, toxicological studies, and precision medicine. In 3D cell culture, for example, stem cells are grown in a support structure that creates an environment mimicking the human body for cell development.
"3D cell samples create a simplified model of real tissues. They can be used, for example, to study diseases and develop suitable medicines for them. The samples are also used to reduce the need for animal testing," says Lehti-Polojärvi.
It is important to assess the functionality of 3D cell samples – such as spheroids and organoids – so that the efficiency and safety of the developed research and treatment methods can be evaluated before clinical use. Hence, there is a great need for 3D imaging methods because traditional microscopy techniques are harmful to living samples or they are limited in imaging the deep structures of the samples.
“By integrating electrical impedance tomography with optical imaging, we can benefit from the strengths of both methods and produce new information about the condition of cell cultures. Electrical imaging reveals the conductivity of the sample, and, with simultaneous optical imaging, we can find out the location and shape of the sample”, Lehti-Polojärvi explains.
In her doctoral research, Lehti-Polojärvi investigated, among other things, the effect of the integrity of tissue cell membranes on electrical conductivity. The results confirmed that the developed technique produces an accurate conductivity spectrum of the sample, which can be used to analyse its viability.
Because the imaging of the electrical properties of cell cultures is still a relatively new technology, more research is needed on the correlation of biological phenomena and conductivity images. All in all, the imaging technique Lehti-Polojärvi developed in her dissertation research offers a novel analysis method for researchers and opens new opportunities in 3D tissue engineering.
Lehti-Polojärvi is from Tampere. She is working at Tampere University’s OrganAnalytics project, which is a Research to Business project funded by Business Finland.
Public defence on Friday 3 November
The doctoral dissertation of MSc (Tech.) Mari Lehti-Polojärvi in the field of biomedical engineering titled Electrical Impedance Tomography Integration with Optical Imaging for 3D in vitro Applications will be publicly examined at the Faculty of Medicine and Health Technology of Tampere University at 12 o’clock on Friday, 3 November 2023. The public defence will be held in auditorium F114 of the Arvo building (address: Arvo Ylpön katu 34, Tampere). The Opponent will be Professor Tanja Tarvainen from the University of Eastern Finland and the Custos will be Professor Jari Hyttinen from Tampere University.
The doctoral dissertation is available online.
The public defence can be followed via a remote connection.
Photograph: Meri Hämäläinen