1: Ann Biomed Eng. 2007 Dec;35(12):2138-44. Epub 2007 Sep 12.

A numerical model of skin electropermeabilization based on in vivo experiments.

Pavselj N, Préat V, Miklavcic D.

Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, SI-1000, 
Ljubljana, Slovenia.

As an alternative to viral methods that are controversial because of their safety
issues, chemical and physical methods have been developed to enhance gene
expression in tissues. Reversible increase of the cell membrane permeability
caused by the electric field--electroporation--is currently one of the most
efficient and simple non-viral methods of gene transfer. We performed a series of
in vivo experiments, delivering plasmids to rat skin using external plate
electrodes. The experiments showed that skin layers below stratum corneum can be 
permeabilized in this way. In order to study the course of skin tissue
permeabilization by means of electric pulses, a numerical model using the finite 
element method was made. The model is based on the tissue-electrode geometry and 
electric pulses used in our in vivo experiments. We took into account the layered
structure of skin and changes of its bulk electrical properties during
electroporation, as observed in the in vivo experiments. We were using tissue
conductivity values found in literature and experimentally determined electric
field threshold values needed for tissue permeabilization. The results obtained
with the model are in good agreement with the in vivo results of gene
transfection in rat skin. With the model presented we used the available data to 
explain the mechanism of the tissue electropermeabilization propagation beyond
the initial conditions dictated by the tissue initial conductivities, thus
contributing to a more in-depth understanding of this process. Such a model can
be used to optimize and develop electrodes and pulse parameters.

PMID: 17849185 [PubMed - indexed for MEDLINE]

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