Quantitative assessment of dielectric parameters for membrane lipid bi-layers from RF permittivity measurements.
Bioelectromagnetics
; 30(4): 286-98, 2009 May.
Article
en En
| MEDLINE
| ID: mdl-19191229
ABSTRACT
In this article, we propose and validate theoretical and experimental methods to quantitatively assess the Debye dielectric model of membrane lipid bi-layers. This consists of two steps:
permittivity measurements of biological solutions (liposomes), and estimation of the model parameters by inverse application of the Effective Medium Theory. The measurements are conducted in the frequency domain between 100 MHz and 2 GHz using a modified coaxial connector, at the temperatures of 27 and 30 degrees C. Estimations have been performed using a three-layered model based on the Maxwell-Wagner formulation. Debye parameters (mean value +/- standard error) found from fitting experimental data are epsilon(s) = 11.69 +/- 0.09, epsilon(infinity) = 4.00 +/- 0.07, f(relax) = 179.85 +/- 6.20 MHz and epsilon(s) = (1.1 +/- 0.1) x 10(-7) S/m. This model can be used in microdosimetric studies aiming to precisely determine the E-field distribution in a biological target down to the single cell level. In this context the use of an accurate membrane dielectric model, valid through a wide frequency range, is particularly appropriate.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ondas de Radio
/
Conductividad Eléctrica
/
Membrana Dobles de Lípidos
/
Modelos Biológicos
Idioma:
En
Revista:
Bioelectromagnetics
Año:
2009
Tipo del documento:
Article
País de afiliación:
Italia