2017 Impact factor 1.802
Soft Matter and Biological Physics

Eur. Phys. J. E 2, 161-168

Noise measurements in bilayer lipid membranes during electroporation

A. Ridi1 - E. Scalas2 - A. Gliozzi1

1 Istituto Nazionale per la Fisica della Materia and Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146, Genova, Italy
2 Dipartimento di Scienze e Tecnologie Avanzate, Universtià del Piemonte Orientale, Corso Borsalino 54, 15100, Alessandria, Italy
gliozzi@fisica.unige.it

Received 1 June 1999 and Received in final form 1 October 1999

Abstract
A study of voltage fluctuations in bilayer lipid membranes during electroporation and under current-clamp conditions is presented. Qualitative considerations based on the electroporation theory are used in order to explain the phenomenon on long time scale. Indeed, the current-clamp condition induces a feedback mechanism on the pore formation and therefore on the macroscopic conductance. Voltage fluctuations can thus be recorded. These fluctuations are nonstationary long-living and have a flicker power spectrum over nearly four decades of frequency between about 10-2 and 102 Hz. The study of the fluctuations in the time domain has been performed by introducing an electrical model of the system formed by the membrane and the circuit under current-clamp configuration. The analysis of the time series gives a characteristic time of 100 ms for the circuitry response to the fragments of electroporation signals with characteristic times faster than 100 ms. During electroporation, the response to an external periodic stimulus in the frequency range 10-1-10 Hz shows that the system behaves linearly, even if voltage fluctuations are present.

PACS
87.16.Dg Membranes, bilayers, and vesicles - 87.68.+z Biomaterials and biological interfaces - 87.15.Ya Fluctuations

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