title: Effects of small pulsed nanocurrents on cell viability in vitro and in vivo: implications for biomedical electrodes.
abstract: Using a custom-built, implantable pulse generator, we studied the effects of small pulsed currents on the viability on rat aortic-derived cells (RAOC) in vitro. The pulsed currents (0.37A/m(2)) underwent apoptosis within 24h as shown by the positive staining for cleaved caspase-3 and classically apoptotic morphology. Based on these findings, we examined the effects of nanocurrents in vivo. The pulse generator was implanted subcutaneously in the rat model. The electrode|tissue interface histology revealed no difference between the active platinum surface and the neighboring control surface, however we found a large difference between electrodes that were functional during the entire experiment and non-active electrodes. These non-active electrodes showed an increase in impedance at higher frequencies 21 days post-implantation, whereas working electrodes retained their impedance value for the entire experiment. These results indicate that applied currents can reduce the impedance of implanted electrodes.
authors.affiliation: Laboratory of Biosensors and Bioelectronics, ETH Zurich, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Gabi
authors.forename: Michael E
authors.initials: ME
authors.lastname: Bullen
authors.forename: Irina
authors.initials: I
authors.lastname: Agarkova
authors.forename: Dörthe
authors.initials: D
authors.lastname: Schmidt
authors.forename: Roman
authors.initials: R
authors.lastname: Schoenauer
authors.forename: Chad
authors.initials: C
authors.lastname: Brokopp
authors.forename: Maximilian Y
authors.initials: MY
authors.lastname: Emmert
authors.forename: Alexandre
authors.initials: A
authors.lastname: Larmagnac
authors.forename: Takumi
authors.initials: T
authors.lastname: Sannomiya
authors.forename: Benedikt
authors.initials: B
authors.lastname: Weber
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Wilhelm
authors.forename: Janos
authors.initials: J
authors.lastname: Vörös
authors.forename: Simon P
authors.initials: SP
authors.lastname: Hoerstrup
mesh_terms: D000818:Animals; D020811:Biomedical Technology / Q000295:instrumentation*; D016923:Cell Death; D002470:Cell Survival; D017097:Electric Impedance; D004560:Electricity; D004566:Electrodes; D049329:Nanostructures / Q000737:chemistry*; D019919:Prosthesis Implantation; D051381:Rats; D017207:Rats, Sprague-Dawley