Phase evolution of lamellar cationic lipid-DNA complex: Steric effect of an electrolyte

Abstract

The complexation isotherms of DNA plus lipids of a symmetric lamellar cationic lipid-DNA system were determined within a mean field free energy. The free energy incorporates the ion's finite size of NaCl simple electrolyte in solution and makes use of known structure data on this complex. The results for the predicted isotherms are in qualitative agreement with the trends of the experimental data for this property.

Counterion volume effects in mixed electrical double layers

“…(1) is generally used in (mean-field, selfconsistent) lattice-based models, see, e.g., Refs. [22][23][24][25]. It must be noted that such models not only underestimate the excluded volume (e.g., in the dilute limit by a factor of 8) but often take the size of a lattice equal to the size of a solvent molecule, not the hydrated ion size.…”

Structural thermodynamics of lamellar cationic lipid-DNA complex: DNA compressibility modulus

“…11,12 It was found to reproduce the general trends of the experimentally measured isotherms. 12 Based on this theory, all possible lipid-DNA composite phases were determined, 13 and the interplay of spatial corrugations and charge lipid modulations in these complexes was demonstrated. 14 In this paper we used the theoretical approach of Harries et al to obtain numerical solutions of the full nonlinear PB equation and we made a fit of a parametrized form of a hydration repulsion, including the van der Waals interaction and negligible ion size at c * = 2 mM electrolyte concentration.…”

Biological physics in México

“…Although institutions like the Instituto de Fisiología Celular [30][31][32] at UNAM and the Center for Research and Advanced Studies (Cinvestav) offer graduate programs in biophysics, their emphasis is more in the biological side of the subject [32,33]. With regards to BP, Cinvestav's physics department is already developing a research core [34][35][36][37][38][39], which other departments at Cinvestav are also doing research in biological physics and related issues [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. We also should account for the work at the biophysics group in the Instituto de Física y Matemáticas of the Universidad Michoacana San Nicolás Hidalgo [58], as well as the Instituto de Ciencias Físicas [59][60][61][62][63][64][65][66][67][68][69][70][71][72], Instituto de Física [73]…”