DNA solutions with multivalent salts and amphiphiles

Polyelectrolytes are of great importance in different branches of chemistry and biology. DNA is a very good example of a polyelectrolyte of biological relevance. In this paper, we describe DNA solutions in the presence of mul tivalent salts and amphiphiles. After thermodynamic equilibrium is reached, the amphiphiles and the multivalent salts associate to DNA, leading to the formation of complexes. As the density of amphiphiles increases, we observ e charge inversion of DNA complexes at not too high amphiphile densities. T he formation of DNA-amphiphile complexes is essential for developing delive ry systems in gene therapy, and we see that it is possible to reverse the c harge of DNA even in the presence of multivalent salts. (C) 2001 Elsevier S cience B.V. All rights reserved.