Novel polymer can travel into cells, deliver genetic cargo, allows tracking

08-Oct-09

A research team has developed a new polymer that can travel into cells, deliver genetic cargo, and packs a beacon so scientists can follow its movements in living systems. The scientists created novel polycations. A polycation is a polymer chain with positive charges, which is not too unusual. DNA itself is a polyanion, a polymer with negative charges. However, the Reineke Group's supramolecule has options. It contains chemistry (oligoethyleneamines) that binds and compacts nucleic acids – pieces of the DNA – into nanoparticles. It also incorporates a group of rare-earth elements known as lanthanides. The repackaged DNA is protected from damage as it travels into the cells and the lanthanides allow visualization of the delivery into cells. In the experiments, these delivery beacons provide the ability to track DNA delivery into living cells. They provide the potential for tracking genetic therapies within the living body. At the nanometer or cellular scale, the researchers are able to track the polymers using sensitive microscopes, which capture the nanoparticle luminescence. At the sub-millimeter or tissue scale, magnetic resonance imaging (MRI) is used to see where the nanoparticles are going. This ability to track the movement and delivery of a gene-based drug provides an opportunity to understand the mechanism of delivery and monitor efficacy in real time, so that we can develop better materials for delivering genetic therapeutics and ultimately better treatments. Theresa M. Reineke, associate professor of chemistry in the College of Science, and colleagues in her lab at Virginia Tech and at the University of Cincinnati have developed this new molecule in an attempt to find a way to deliver genetic-based drugs into cells. Genetic drugs – such as those that can alter or control gene expression – aim to treat disease at the genetic level and have the added benefit of being more specific for their medicinal target. A challenge has been that DNA and RNA drugs – pieces of genetic code that store information and instructions – cannot diffuse through the cell the way traditional small molecule drugs can. Hence a vehicle was needed to carry them into cells.