MADISON - Gene therapy - the idea of using genetic instructions rather than drugs to treat disease - has tickled scientists' imaginations for decades, but is not yet a viable therapeutic method. One sizeable hurdle is getting the right genes into the right place at the right time.
Engineers at the University of Wisconsin-Madison are now developing a tool to tackle this problem. David M. Lynn and his colleagues have created ultrathin, nanoscale films composed of DNA and water-soluble polymers that allow controlled release of DNA from surfaces. When used to coat implantable medical devices, the films offer a novel way to route useful genes to exactly where they could do the most good. Lynn, a UW-Madison professor of chemical and biological engineering, has used his nanoscale films to coat intravascular stents, small metal-mesh cylinders inserted during medical procedures to open blocked arteries. While similar in concept to currently available drug-coated stents, Lynn's devices could offer additional advantages. For example, Lynn hopes to deliver genes that could prevent the growth of smooth muscle tissue into the stents, a process which can re-clog arteries, or that could treat the underlying causes of cardiovascular disease.
Preliminary laboratory tests of the DNA-coated materials are promising. "The films survive basic mechanical forces associated with placement and expansion of stents," Lynn says. He and his colleagues have also demonstrated gene delivery to cells grown in a dish.
In preliminary experiments conducted in collaboration with Matthew Wolff, Timothy Hacker, and Jose Torrealba in the UW School of Medicine and Public Health, Lynn has shown that DNA film-coated stents can successfully deliver a gene encoding a fluorescent protein into a rabbit's artery, demonstrating that the films can also work in the complex environment of living tissue. Lynn presented a summary of the work at the annual spring meeting of the American
Contact: David Lynn
University of Wisconsin-Madison