Flexible sheet-type sensor device. (a) Photograph of the flexible sensor device. (b) An array of microchamber structures integrated with a thin phosphorescent sensing layer (red color) below fabricated on a transparent flexible polymer sheet. (c) Cross-sectional image of the sensor. (Image: Takanori Ichiki)
Although evaluation of cellular quality and activity is important in the field of drug development and regenerative medicine, conventional cellular analysis methods tend to hurt or modify the measured cells.?As a result, researchers have been searching for sensors that allow noninvasive measurement of cultivated cells and that can be easily removed after measurement.
The research group, comprising Associate Professor Takanori Ichiki at the Graduate School of Engineering, the University of Tokyo and Nikon, has developed a flexible sensors that allows sensitive and noninvasive measurement of cellular metabolism of cultivated cells or sliced tissues and can easily be removed after use. The sensor comprises a flexible and transparent polymer sheet having a number of small holes, called as microchambers, whose diameter is as fine as that of hair. On the bottom of each hole, a thin sensing layer containing a phosphorescent metal complex shows a phosphorescence emission response dependent on the oxygen concentration.
“The combined use of the sensor and an automated optical measurement system to monitor the phosphorescence enabled high-throughput sensing of cellular oxygen consumption at 100 points per minute. We successfully monitored the oxygen metabolism of cancer cells on a Petri dish, and furthermore, demonstrated the mapping of oxygen consumption rate of rat brain slices,” says Associate Professor Ichiki. He continues, “This sensor sheet is suitable for mass production and we expect will have widespread applications in drug discovery and in quality control of cultivated cells for regenerative medicine.”