title: System for measuring oxygen consumption rates of mammalian cells in static culture under hypoxic conditions.
abstract: Estimating the oxygen consumption rates (OCRs) of mammalian cells in hypoxic environments is essential for designing and developing a three-dimensional (3-D) cell culture system. However, OCR measurements under hypoxic conditions are infrequently reported in the literature. Here, we developed a system for measuring OCRs at low oxygen levels. The system injects nitrogen gas into the environment and measures the oxygen concentration by an optical oxygen microsensor that consumes no oxygen. The developed system was applied to HepG2 cells in static culture. Specifically, we measured the spatial profiles of the local dissolved oxygen concentration in the medium, then estimated the OCRs of the cells. The OCRs, and also the pericellular oxygen concentrations, decreased nonlinearly as the oxygen partial pressure in the environment decreased from 19% to 1%. The OCRs also depended on the culture period and the matrix used for coating the dish surface. Using this system, we can precisely estimate the OCRs of various cell types under environments that mimic 3-D culture conditions, contributing crucial data for an efficient 3-D culture system design.
authors.affiliation: Inst. for Nanoscience and Nanotechnology, Waseda University, 2-2 Wakamatsu-Cho, Shinjuku, Tokyo, 162-8480, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kagawa
authors.affiliation: Dept. of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-Cho, Shinjuku, Tokyo, 162-8480, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Miyahara
authors.affiliation: Dept. of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-Cho, Shinjuku, Tokyo, 162-8480, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Ota
authors.affiliation: Inst. for Nanoscience and Nanotechnology, Waseda University, 2-2 Wakamatsu-Cho, Shinjuku, Tokyo, 162-8480, Japan.|Dept. of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-Cho, Shinjuku, Tokyo, 162-8480, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsuneda
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D015687:Cell Hypoxia; D056945:Hep G2 Cells; D006801:Humans; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D010101:Oxygen Consumption
chemical_list: D009584:Nitrogen; D010100:Oxygen
keywords: HepG2 cell; collagen-coated; hypoxia; matrigel-coated; oxygen consumption