Drug Delivery; Local lipid membrane diffusion coefficients calculated for electroporation
9 November 2006
Gene Therapy Weekly
(c) Copyright 2006 Gene Therapy Week via NewsRx.com
2006 NOV 9 - (NewsRx.com) -- A study from the United States has reported on microscopic calculations of local lipid membrane permittivities and diffusion coefficients for application to electroporation analyses.
"Interaction of electric fields with biological systems has begun to receive considerable attention for applications that include field-assisted drug delivery, medical interventions, and genetic engineering. External fields induce the strongest effects at membranes with electroporation being a common feature.
"Membrane transport in this context of poration is often based on continuum approaches utilizing macroscopic parameters such as the permittivity, diffusion coefficients, and mobilities. In such modeling, field dependences, local inhomogeneities, and microscopic details are usually ignored," wrote R.P. Joshi and colleagues, Old Dominion University.
"Here, a molecular dynamics (MD) scheme is used for a more rigorous and physically realistic evaluation of such parameters for potential application to electroporative transport model development. A suitable membrane structure containing a nanopore derived from MD analysis is used as the initial geometric configuration.
"Both static and frequency dependent diffusion coefficients have been evaluated. Permittivities are also calculated and shown to be dramatically non-uniform in the vicinity of membranes under high external fields," reported the authors.
The researchers concluded, "A positive feedback mechanism leading to enhanced membrane fields is discussed."
Joshi and colleagues published their study in Biochemical and Biophysical Research Communications (Microscopic calculations of local lipid membrane permittivities and diffusion coefficients for application to electroporation analyses. Biochem Biophys Res Commun, 2006;348(2):643-648).
Additional information can be obtained by contacting R.P. Joshi, Old Dominion University, Department of Electrical & Computational Engineering, Norfolk, VA 23529, USA.
This article was posted on: November 9, 2006
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