Charge inversion in DNA-amphiphile complexes: Possible application to gene therapy

TL;DR

This study investigates how DNA interacts with cationic amphiphilic molecules, revealing conditions under which charge inversion occurs, which could enhance gene therapy by improving DNA delivery into cells.

Contribution

It demonstrates the conditions for charge inversion in DNA-amphiphile complexes, highlighting potential applications in gene therapy.

Findings

Charge inversion occurs with sufficiently hydrophobic amphiphiles.

Binding transition depends on salt concentration and surfactant hydrophobicity.

Charge inversion may facilitate DNA transfection into cells.

Abstract

We study a complex formation between the DNA and cationic amphiphilic molecules. As the amphiphile is added to the solution containing DNA, a cooperative binding of surfactants to the DNA molecules is found. This binding transition occurs at specific density of amphiphile, which is strongly dependent on the concentration of the salt and on the hydrophobicity of the surfactant molecules. We find that for amphiphiles which are sufficiently hydrophobic, a charge neutralization, or even charge inversion of the complex is possible. This is of particular importance in applications to gene therapy, for which the functional delivery of specific base sequence into living cells remains an outstanding problem. The charge inversion could, in principle, allow the DNA-surfactant complexes to approach negatively charged cell membranes permitting the transfection to take place.