Nanocarrier stimuli-activated gene delivery

Jan 29 2007

One approach to developing tumor-specific drug delivery agents is to create nanomaterials that release a therapeutic payload only after reaching their intended target.

Researchers at the University of Aarhus, in Denmark, have taken such an approach to develop nanocarriers that can be triggered to deliver genes to diseased tissues.

Reporting its work in the journal Small, a team of investigators led by Kenneth Howard, Ph.D., and Flemming Besenbacher, Ph.D., described how they developed a temperature-sensitive polymer capable of complexing with DNA and forming nanorods that are stable at body temperature, or 37°C. However, when heated to 42°C, these rods expand dramatically, becoming too large to pass into or out of blood vessels. The researchers note that localized heating could be used to trap these nanorods in tumors, in essence creating a new way of targeting a drug delivery agent to tumors.

When exposed to the unique physiological conditions found inside tumors, these nanorods display another useful characteristic – they fall apart. The researchers believe that this disassembly is thorough enough that the polymer no longer complexes at all with the DNA cargo. Electron microscopy studies appear to confirm this finding, suggesting that these nanorods could indeed deliver therapeutic genes into cancer cells.

This work is detailed in a paper titled, “Nanocarrier stimuli-activated gene delivery.” Investigators from Wayne State University also participated in this study. An abstract of this paper is available at the journal’s website. View abstract.