Microphysiometer

Microphysiometers Microplant Micropollutants Micropore diffusion Microporite... 

Cytosensor Microphysiometer technology has been used to detect perturbation in mammalian cells (Hafner, 2000). The system measures small changes in extracellular acidification using a light addressable potentiometric sensor. If the metabolism is interfered with, acid excretion will be affected which could be sensitively measured by LAPS. In principle, this system should be suitable for monitoring pathogen interaction with mammalian cells. 

Hafner, E. (2000). Cytosensor(R) microphysiometer Technology and recent applications. Biosens. Bioelectron. 15,149-158. 

McConnell et al. Tlte Cytosensor Microphysiometer Biological Applications of Silicon Technology, Science, 1906 (September 25, 1992). 

Fig. 5.9. Picture of the commercial Cytosensor microphysiometer from Molecular Devices. Four fluid pathways with (1) analyte container, (2) displacement pump, (3) debubbler, (4) valves, (5) LAPS sensor chamber and (6) reference electrode.

H.M. McConnell, J. Owicki, J. Parce, D. Miller, G. Baxter, H. Wada and S. Pitchford, The Cytosensor microphysiometer biological applications of silicon technology, Science, 257(5078) (1992) 1906-1912. 

D. Bironaite, L. Gera and J.M. Stewart, Characterization of the B2 receptor and activity of bradykinin analogs in SHP-77 cell line by Cyto-sensor microphysiometer, Chem. Biol. Interact., 150(3) (2004) 283-293. 

S.E. Eklund, D. Taylor, E. Kozlov, A. Prokop and D.E. Cliffel, A microphysiometer for simultaneous measurement of changes in extracellular glucose, lactate, oxygen, and acidification rate, Anal. Chem., 76(3) (2004) 519-527. 

Z. Xiaoxiang, A novel microphysiometer based on mLAPS for drugs screening, Biosens. Bioelectron., 16(4-5) (2001) 277-286. 

The challenge of establishing hundreds or thousands of electrical contacts if such amperometrically transduced microphysiometers are massive parallelized can be satisfied by multiplexing the individual sensors by CMOS components integrated on a silicon wafer [113]. 

For adherenl cells, the retention of cells for measurements is straightforward. For instance, a microphysiometer was constmcted to detect the change in cellular acidity (due to lactate and C02 formation) of mammalian cells. The acidity was measured using the light-addressable potentiometer sensor (LAPS) fabricated on a Si chip (see Figure 8.15) [848]. 

In one report, kidney cells of Xenopus laevis (A6) were cultured in a 96-well Si microphysiometer sensor array [897], Mouse fibroblasts (3T3-J2) were cultured in stacked PU microstructures that mimic the bone architecture. PU is used because it is biocompatible [160],... 

Functional assays such as Ca2+ mobilization and chemotaxis (see Chapters 16 and 11 respectively, in this volume) or microphysiometer analysis (4) in response to ligand stimulation. 

McConnell HM, Owicki JC, Parce JW, Miller DL, Baxter GT, Wada HG, et al. The cytosensor microphysiometer Biological applications of silicon technology. Science 1992 257 1906-12. 

Cytosensor microphysiometer (CM) Validated in 2009, Draft OECD TG Applicable to water-soluble substances and mixtures. 

The Cytosensor Microphysiometer (CM) test method is currently under discussion (draft test guideline on the Cytosensor Microphysiometer) at OECD level [34], It is a cytotoxicity and cell-function based in vitro assay that is performed on a sub-confluent monolayer of adherent mouse L929 fibroblasts cultured in a sensor chamber using a pH-meter to detect changes in acidity [35]. The CM test method serves as an in vitro model system for the cytotoxic action of a test chemical on the cell membranes of the corneal and conjunctival epithelium where the irritant chemical would be... 

Cytosensor Microphysiometer Test Method an in vitro method for identifying ocular 3 corrosive and severe irritant chemicals as well as chemicals not classified as ocular irritants. Available at http //www.oecd.org/env/... 

A more recent cell-based in vitro assay involves the use of the microphysiometer, a sensitive extracellular pH sensor, which has been used to measure luminal (or apical) secretion and basolateral release of OH- as well as liberation of acidic metabolites in rabbit gastric glands. Adenosine 3, 5 -cyclic monophosphate stimulation produced a biphasic change... 

Compound 6m, a chiral molecule, was resolved and the enantiomers, (R)-6m (CI-1017) and (S)-6m, evaluated for muscarinic receptor subtype selectivity in a battery of in vitro and in vivo assays (Tables 9-12). The effect of the enantiomers on receptor-mediated cellular metabolism of Hm, Hm2, Hmj, and Hm4 CHO cells was measured (Table 9). Enhanced cellular metabolism results in increased acidification of environment of the cells which can be measured by a microphysiometer. The results show that 6m and its enantiomers have no efficacy at M2 receptors. The enantiomer (R)-6m is M[-selective and at non-M2 receptors, it is 5- to 10-fold more potent than the (5)-6m enantiomer. 

McConnell. H.M., 1992. The cytosensor microphysiometer biological applications of silicon technology. Science 257, 1906-1912. 

Brunner, L, H.. Miller, K. R., Owicki, J. C.. Parcc, J. W and Muir, V C. (1991b). Testing ocular in-itancy in vita with the silicon microphysiometer. Toxicol, in Vitro 5,277-284,... 

Catfoux. P Ebcr, C. A., and Panfalli. 1. (1993a). Surfactant toxicity determined in vitro by silicon microphysiometer. In Alternative Methods in Toxicology (A. M. Golbcrg, Ed.), vol. 9. Libert. New York. 

---