title: The use of SU-8 topographically guided microelectrode array in measuring extracellular field potential propagation.
abstract: The microelectrode array (MEA) can be used to study extracellular field potentials (exFPs) of electrogenic cells. Microcontact printing, which must be repeated after each experiment, is often used to promote accurate positioning of cells onto electrodes. The present study used MEAs with evenly spaced detection electrodes aligning along permanent SU-8 topographical guidance channels to measure propagation direction and speed. Chronotropic agents, isoproterenol (ISO, 1 nM-1 mM), and verapamil (VP, 1 nM-10 μM); and potassium channel openers (KCOs), pinacidil (PIN), and SDZ PCO400 (SDZ), were used to characterize these MEA chips. ISO (1 mM) enhanced the propagation speed from 247.25 ± 50.58 μm/ms 381.29 ± 92.01 μm/ms (n = 9, p < 0.05), whereas VP (10 μM) reduced the propagation speed completely (n = 12, p < 0.001). PIN (1 mM) significantly reduced the propagation speed from 278.6 ± 43.7 μm/ms to 49.7 ± 27.7 μm/ms (n = 10, p < 0.001), whereas SDZ (1 mM) completely stopped the propagation (n = 9, p < 0.001). Both KCOs induced conduction pattern changes similar to those observed in cardiac arrhythmia. The MEA chips with SU-8 guidance channels may be used to study cardiovascular diseases that are related to conduction disruption.
authors: Bioengineering Graduate Program, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors: Jessica Ka-Yan
authors: JK
authors: Law
authors: Chi-Kong
authors: CK
authors: Yeung
authors: Lin
authors: L
authors: Li
authors: John Anthony
authors: JA
authors: Rudd
authors: Sven
authors: S
authors: Ingebrandt
authors: Mansun
authors: M
authors: Chan
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology; D001698:Biomedical Engineering; D002317:Cardiovascular Agents / Q000494:pharmacology; D002478:Cells, Cultured; D055724:Electrophysiological Phenomena; D008564:Membrane Potentials / Q000187:drug effects; D008839:Microelectrodes; D008855:Microscopy, Electron, Scanning; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D015221:Potassium Channels / Q000819:agonists; D051381:Rats
chemical_list: D002317:Cardiovascular Agents; D015221:Potassium Channels