Providing insight on bio-molecular interactions with biological membranes by using supported lipid bilayers

Tommy Nylander
Thursday, January 19, 2012
Duke University, 12pm | CIEMAS 2240

The biological membrane is one of the most important interfaces that the drug delivery vehicles encounter. The barrier function of the membrane is provided by the lipid bilayer. Lipids and lipid self-assembly structures are important as regulators for biological activity that can be exploited for the design of drug delivery vehicles. We have used simple supported lipid bilayers as models for biological membranes. These membrane models has allowed us to study the biophysics of biomolecular interactions using a range of surface techniques including neutron scattering. 

Modern medicine has found ways to treat diseases, caused by genetic defects, by “repairing” the DNA, so-called gene therapy. One of the main challenges with gene therapy is to deliver the nucleic acids across the membrane. Knowledge of how DNA and RNA interact with lipids is central to the understanding of organization and function of these molecules in biological systems. The main obstacle here is the charge as well as the extensive size of the DNA in solution. In gene therapy one often utilizes vehicles with the ability to condense DNA and thereby protect DNA against degradation, transport DNA across membranes as well as regulate gene expression. The compacting agent not only condenses the DNA chain, but depending on the nature and the strength of the interaction often can form intriguing morphologies.  We will discuss how DNA and RNA interact with the lipid membrane and how this interaction can be manipulated with compacting agents.