Stem cell-based cell and tissue models can be used to study the functioning of various cells and tissues, development of diseases and traumas as well as the influence of medical substances or toxins. In addition, the models provide tools for a personalized medical testing and manufacturing of body spare parts.
An appropriate cell model requires a precise control of environmental conditions. Especially temperature, pH and oxygen tension need to be carefully regulated. For example, the oxygen monitoring is particularly important when creating ischemic conditions, i.e. oxygen deprivation in tissues, which is linked to many important diseases. A central component of the cell model control system is an oxygen sensor, which should generate real time information about the oxygen condition reliably and without harm or disruption to the cells. The dissertation developed oxygen measurement methods based on luminescent, i.e. light-emitting oxygen-sensitive indicators.
”Surface-selective optical measurement technologies combined with a biocompatible luminescent indicator material provides an excellent way for a real time oxygen monitoring that is highly sensitive, reliable and gentle for the cells. It also enables accurate local measurements and smoothly merges into a modular cell culturing system combining many measurement and imaging functions, developed in our research group“, Välimäki says.
In his dissertation, Välimäki has developed both optical sensing set-ups and biocompatible indicator materials. However, his work with the surface-selective luminescence methods started at VTT, the Technical Research Centre of Finland, more than ten years ago, when he developed technologies for rapid on-site drug screening.
“At that time, we understood that the surface-selective luminescence methods allow real-time monitoring of labelled immunological binding events even in challenging biological samples without any sample pretreatment. Based on this, we were able to speed up multiple developed drug tests”, Välimäki tells.
In addition to the drug screening, the measurement methods developed by Välimäki are well-suited for immunoassays of many other interesting molecules, including medical substances, hormones, environmental toxins, antibodies and viruses. The Covid-19 pandemic is a dire reminder of the importance of developing rapid medical tests.
Hannu Välimäki was born in Turku and graduated with M.Sc. (Tech) in Tampere. Today he works as a researcher at the Centre of Excellence in in Body-on-Chip Research at the Tampere University.
The doctoral dissertation of M.Sc. (Tech) Hannu Välimäki in the field of Biomedical Sciences and Engineering titled Surface-selective Luminescence Methods ─ Enabling technologies for rapid immunoassays and chemical sensing in cell cultures will be publicly examined in the Faculty of Medicine and Health Technology at Tampere University at 12 o’clock on Friday, August 28, 2020. The Opponent will be Professor Carl-Fredrik Mandenius from Linköping University, Sweden. The Custos will be Professor Emeritus Jukka Lekkala from the Faculty of Medicine and Health Technology.
Due to the coronavirus situation, the public defence is organized via digital platform. Backup connection, meeting ID: 690 5166 2445
The dissertation is available online at
http://urn.fi/URN:ISBN:978-952-03-1633-4
Photo: Maija Välimäki