Self-assembled complexes of biopolymers and charged membranes

Gerard C. L. Wong

Materials Science & Engineering Department and Physics Department

University of Illinois at Urbana-Champaign

We describe recent work on biopolymer-membrane complexes, which self-assemble through electrostatic and entropic interactions. These interactions are quite general, since all nucleic acids, all cell membranes, as well as most proteins and sugars are charged. Early examples include complexes of DNA and cationic lipids for non-viral gene therapy. We have examined the ‘design rules’ of such complexes by investigating other forms of anionic biopolymer-cationic membrane assembly comprised of biopolymers of different charge, flexibility, and radii. Furthermore, we have used these complexes to template inorganic crystals with crystallographic control. The components which self-assemble are frequently oppositely-charged, but in contrast to intuition, they can be like-charged as well. We will also describe novel mesophases of complexes formed from anionic biopolymers and anionic membranes, mediated through multivalent ions. Potential applications of these self-assembled systems will be discussed .