Effective non-invasive methods for determining the physiological properties and ultimately the quality of cells cultivated in-vitro using Petri dishes are important for regenerative medicine and screening of drugs. In particular, the accurate measurement of metabolic parameters such as pH and oxygen is important for clinical applications of such cells.
Now Takanori Ichiki at the University of Tokyo and colleagues in Japan have successfully developed a sheet-type sensor for the non-invasive measurement of oxygen metabolism of cells and tissues cultivated in a Petri dish. This approach takes direct physiological measurements of cells and tissues as they grow in Petri dishes and an integrated automated optical system enables the rapid and precise monitoring of volatile cellular oxygen consumption.
The device comprises of a transparent EVOH/PDMS polymer sheet incorporating micro-chamber structures imbedded with oxygen sensitive phosphor dyes, and in this report was placed over MCF7 breast cancer cells on a Petri dish for physiological measurements.
Moreover, it is known that the oxygen concentration in the micro-chamber varies linearly with the lifetime of phosphorescence dyes in the sensing layer, hence changes in the oxygen concentration are obtained by optically measuring the time dependence of the phosphorescence intensity. Using this method, the oxygen consumption rate of MCF7 cancer cells was determined to be 0.72 fmol/min/cell, confirming previous reports.
Furthermore, the group measured the oxygen consumption rate of rat brain slices in real time thereby demonstrating the potential expansion of the applications of their device to neuroscience.
The development of appropriate phosphor probes for embedding in the sensing layer is expected to lead to the system becoming a versatile analytical tool for research on drug screening and cell cultivation.
Reference and affiliation
Mari Kojima1, Hiroaki Takehara1, Takanori Akagi1, Hirofumi Shiono2, Takanori Ichiki1*
Flexible Sheet-Type Sensor for Noninvasive Measurement of Cellular Oxygen Metabolism on a Culture Dish, PLoSONE10(12): e0143774. doi:10.1371/journal.pone.0143774
- Department of Bioengineering, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyoku, Tokyo, Japan
- Nikon Corporation, 2-15-3, Konan, Minato-Ku, Tokyo, Japan
*corresponding author email address: firstname.lastname@example.org
Fig. The experiment is done by directly attaching the embossing polymer device to the Petri dish to form an enclosed space with cells in observation. An optical system was placed under the dish to detect the phosphorescence emission from the sensing layer to deduct the oxygen concentration in the microspace.