title: Reaction-diffusion modelling for microphysiometry on cellular specimens.
abstract: Using modeling and simulation, we quantify the influence of spatiotemporal dynamics on the accuracy of data obtained from sensors placed in microscaled reaction volumes. The model refers to cellular reaction (i.e. proton extrusion and oxygen consumption) in complex, buffering solutions. Whole cells or viable tissues cultured in such devices are monitored in real time with integrated sensors for pH and dissolved oxygen. A 3D finite element model of diffusion and metabolic reaction was set up. With respect to pH, the effect of buffering species on proton diffusion is analysed in detail. To account for the delayed time response of real sensors, the sensor impulse response time was implemented by linear convolution. A validation of the model has been achieved by an electrochemical approach. The model reveals significant deviations of measured pH and O2, and values of these parameters actually occurring at different sites of the cell culture volume. It is applicable to any setting of (bio-) sensors involving reaction and diffusion of dissolved gases and particularly H(+) ions in buffered solutions.
authors.affiliation: Department Heinz Nixdorf-Lehrstuhl Medizinische Elektronik, Technische Universität München, Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Grundl
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Zhang
authors.forename: Safa
authors.initials: S
authors.lastname: Messaoud
authors.forename: Cornelia
authors.initials: C
authors.lastname: Pfister
authors.forename: Franz
authors.initials: F
authors.lastname: Demmel
authors.forename: Mario S
authors.initials: MS
authors.lastname: Mommer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wolf
authors.forename: Martin
authors.initials: M
authors.lastname: Brischwein
mesh_terms: D003198:Computer Simulation; D003584:Cytological Techniques / Q000295:instrumentation* / Q000379:methods; D004058:Diffusion; D020342:Finite Element Analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008660:Metabolism; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D015203:Reproducibility of Results
chemical_list: D010100:Oxygen