Bioelectricity

In developmental biology, bioelectricity refers to the regulation of cell, tissue, and organ-level patterning and behavior as the result of endogenous electrically mediated signalling. Cells and tissues of all types use ion fluxes to communicate electrically. The charge carrier in bioelectricity is the ion (charged atom), and an electric current and field is generated whenever a net ion flux occurs. Endogenous electric currents and fields, ion fluxes, and differences in resting potential across tissues comprise a signaling system. It functions alongside (in series and in parallel to) biochemical factors, transcriptional networks, and other physical forces to regulate the cell behavior and large-scale patterning during embryogenesis, regeneration, cancer suppression, and many other processes. Overview Developmental bioelectricity is a sub-discipline of biology, related to, but distinct from, neurophysiology and bioelectromagnetics. Developmental bioelectricity refers to the

Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity

Daniel Bertrand, Arnaud Bertsch, Stefan Metz, Philippe Renaud

The study of intracellular communication requires devices that can not only monitor the bioelectric activity, but also control and observe the biochemical environment at the cellular level. This paper reports on the development and characterisation of implantable polyimide microprobes that allow simultaneous, selective chemical delivery/probing and multi-channel recording/stimulation of bioelectric activity. The key component of the system is a flexible polyimide substrate with embedded microchannels that is batch-fabricated combining polyimide micromachining and a lamination technique. The devices provide platinum microelectrodes on both sides of the polyimide substrate with an active surface between 20 mum x 20 mum and 50 mum x 50 mum. The embedded microchannels permit highly localised drug delivery or probing at the tip of the device via channel outlets adjacent to the microelectrodes. The microelectrodes were characterised by electrical impedance spectroscopy and the microchannels were studied in microflow experiments. Two different fluid delivery schemes were explored in two different designs. The first device type consists of a simple combination of microchannels and microelectrodes on one substrate. Liquids are ejected at the tip of the device by pressure injection techniques. The second device was inspired by the so-called U-tube concept allowing for highly localised delivery of controlled amounts of liquids in the picoliters range. Thus, the influence of chemical compounds on the electrical activity of cells can be studied with high temporal and spatial resolution. The flexible, implantable devices can be used for studying the chemical and electrical information exchange and communication of cells in in vivo and in vitro experiments. (C) 2003 Elsevier B.V. All rights reserved.

2004

Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity

Daniel Bertrand, Arnaud Bertsch, Stefan Metz, Philippe Renaud

2004

Characterization of axial-flow packed bed bioreactors for the culture of CHO cells

Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity

Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity

Characterization of axial-flow packed bed bioreactors for the culture of CHO cells