title: Flexible Sheet-Type Sensor for Noninvasive Measurement of Cellular Oxygen Metabolism on a Culture Dish.
abstract: A novel flexible sensor was developed for the noninvasive oxygen metabolism measurement of cultivated cells and tissues. This device is composed of a transparent double-layered polymer sheet of ethylene-vinyl alcohol (EVOH) and poly(dimethylsiloxane) (PDMS) having an array of microhole structures of 90 μm diameter and 50 μm depth on its surface. All the microhole structures were equipped with a 1-μm-thick optical chemical sensing layer of platinum porphyrin-fluoropolymer on their bottom. The three-dimensional microstructures of the sensor were fabricated by a newly developed simple and low-cost production method named self-aligned hot embossing. The device was designed to be attached slightly above the cells cultivated on a dish to form a temporarily closed microspace over the target cells during measurement. Since the change in oxygen concentration is relatively fast in the microcompartmentalized culture medium, a rapid evaluation of the oxygen consumption rate is possible by measuring the phosphorescence lifetime of the platinum porphyrin-fluoropolymer. The combined use of the device and an automated optical measurement system enabled the high-throughput sensing of cellular oxygen consumption (100 points/min). We monitored the oxygen metabolism of the human breast cancer cell line MCF7 on a Petri dish and evaluated the oxygen consumption rate to be 0.72 ± 0.12 fmol/min/cell. Furthermore, to demonstrate the utility of the developed sensing system, we demonstrated the mapping of the oxygen consumption rate of rat brain slices and succeeded in visualizing a clear difference among the layer structures of the hippocampus, i.e., the cornu ammonis (CA1 and CA3) and dentate gyrus (DG).
authors.affiliation: Department of Bioengineering, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Kojima
authors.affiliation: Department of Bioengineering, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takehara
authors.affiliation: Department of Bioengineering, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Akagi
authors.affiliation: Nikon Corporation, 2-15-3, Konan, Minato-ku, Tokyo, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Shiono
authors.affiliation: Department of Bioengineering, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Ichiki
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D061986:MCF-7 Cells; D010101:Oxygen Consumption; D010984:Platinum / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry; D051381:Rats
chemical_list: D004129:Dimethylpolysiloxanes; D011166:Porphyrins; D010984:Platinum; C013830:baysilon