BIOMEDICAL ENGINEERING

Our current generation of DNA nanoparticles consists of plasmid DNA condensed with polylysine covalently coupled to polyethylene glycol (PEG-CK30). For earlier generation DNA nanoparticles, formed in high salt solution, targeting with a ligand for the serpin-enzyme complex receptor (SEC-R) resulted in 10-1000 fold increased gene expression compared to the non-targeted version depending on system, transgene, time after transfection, and dose. Similar improvements in stabilized DNA nanoparticles could allow lower doses to give similar results, or limit the cells transfected, avoiding toxicity. In addition clinical grade DNA is the major manufacturing cost, so reducing the amount needed makes commercial sense. Importantly, once the strategy for addition of targeting ligands is established, other peptides could be substituted and tested, and may present opportunities for introducing DNA into new tissue types (e.g. liver, tumors). The goals of our studies are: 1) to develo p DNA nanoparticles targeted at the SEC-R. 2) to test the targeting of these particles in cell culture and in mice. 3) to test whether SEC-R targeting improves duration as well as intensity of expression for stabilized complexes, as it does for first-generation complexes. 4) to test the immunogenicity of the targeted particles, and to compare these outcomes to non-targeted DNA particles that have been tested in the lab and in the clinic (see references).