Almost all progress in life sciences and biomedical research depend on the delivery of substances into cells. Depending on the field of research, successful delivery of substances (e.g. DNA/genes, proteins, compounds, dyes) enables scientists to observe reactions of the cells or to produce products within cells. Hence, methods and technologies for substance delivery are essential for basic and applied research. Moreover, there is a special demand of technologies without undesired side-effects. For example, biological transfer via virus infection is extremely efficient but might also alter the target cells’ genome and metabolism and hence, interfere with the research question of interest. Moreover, virus based techniques have to meet a set of regulations and demand special facilities. Less efficient chemical transfer methods (e.g. lipids or polymers) are easier to apply but are known for their toxic effects. Both, chemical and virus based methodologies are limited regarding the substances that can be delivered. Finally, physical methods minimize unwanted side effects of reagents or viruses but require cell-stressing pre-treatments and kill a significant number of cells during the procedure. To compensate for that loss, most physical methods require a minimum cell number to start with and therefore, are not suitable for delicate cells nor projects with limited cell material (e.g. primary patient cells). World-wide about 200.000 academic research labs and 50.000 industry labs depend on techniques to deliver substance into cells
The technology gap and the project goals
Given this methodological gap and the demand for new substance delivery tools, we tested the use of microwaves for substance delivery. Within the last year the successful delivery of labeled peptides into adherent cells using a prototype “Microporator” has been tested. The prototype allows monitoring the uptake process kinetics with live-cell (confocal) microscopy and is suitable to culture, manipulate and observe adherent cells over several days. This novel device has the potential to bypass the current technological limitations listed above and successfully fill a market gap. The microwave-assisted substance transfer method does neither depend on a stressful pre-treatment nor cells in suspension. Hence, it becomes possible to treat cells in their native culture condition without the need for potential toxic reagents. Moreover, in contrast to electroporation, the data revealed almost no cell mortality during the treatment. Therefore, the efficiency of microwave assisted transfer does not depend on large initial cell numbers. Finally, it was possible to monitor the transfer of a fluorescent peptide (a small protein) in real-time that was detectable inside cells up to three days after treatment and did not affect cell viability. Consequently, we are convinced that the microwave based approach has the potential to transfer any substance into cells in their native culture state.
Involved Departments, Institutes
The realization and the systematic product development requires the expertise of electrical engineers and cell biologists in close cooperation.
The research interest of the Microwave Engineering Group, lead by Prof. Dr.-Ing. Rolf Jakoby covers among others: tunable passive microwave devices and reconfigurable microwave antennas as well as RFID and microwave sensors.
The research group cell biology and epigenetics under the direction of Prof. Dr. M. Cristina Cardoso is studying the processes of DNA replication, repair and modifications in mammalian cells and related technology development.