title: Noninvasive Oxygen Monitoring in Three-Dimensional Tissue Cultures Under Static and Dynamic Culture Conditions.
abstract: We present a new method for noninvasive real-time oxygen measurement inside three-dimensional tissue-engineered cell constructs in static and dynamic culture settings in a laminar flow bioreactor. The OPAL system (optical oxygen measurement system) determines the oxygen-dependent phosphorescence lifetime of spherical microprobes and uses a two-frequency phase-modulation technique, which fades out the interference of background fluorescence from the cell carrier and culture medium. Higher cell densities in the centrum of the scaffolds correlated with lower values of oxygen concentration obtained with the OPAL system. When scaffolds were placed in the bioreactor, higher oxygen values were measured compared to statically cultured scaffolds in a Petri dish, which were significantly different at day 1-3 of culture. This technique allows the use of signal-weak microprobes in biological environments and monitors the culture process inside a bioreactor.
authors: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School , Hannover, Germany .
authors: Birgit
authors: B
authors: Weyand
authors: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School , Hannover, Germany .
authors: Mariel
authors: M
authors: Nöhre
authors: Colibri Photonics GmbH , Potsdam, Germany .
authors: Elmar
authors: E
authors: Schmälzlin
authors: Colibri Photonics GmbH , Potsdam, Germany .
authors: Marvin
authors: M
authors: Stolz
authors: Biomimetics Technologies, Inc. , Toronto, Canada .
authors: Meir
authors: M
authors: Israelowitz
authors: Biomimetics Technologies, Inc. , Toronto, Canada .
authors: Christoph
authors: C
authors: Gille
authors: Biomimetics Technologies, Inc. , Toronto, Canada . ; University Hand Program and Bone Lab, Department of Surgery, University of Toronto , Toronto, Canada .
authors: Herb P
authors: HP
authors: von Schroeder
authors: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School , Hannover, Germany .
authors: Kerstin
authors: K
authors: Reimers
authors: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School , Hannover, Germany .
authors: Peter M
authors: PM
authors: Vogt
keywords: cell culture; extracellular matrix; hypoxia; stem cells; tissue engineering