In cell cultures, the adenovirus successfully delivered genes from alloy samples to animal arterial smooth muscle cells. In a second experiment using rodents, the researchers detected gene expression with significantly lower restenosis in the carotid arteries of animals with the experimental stents, compared to control animals with conventional, polymer-coated stents.
The researchers used a therapeutic gene that encodes for a protein, inducible nitric oxide synthase (iNOS), in the carotid artery studies, because of iNOS's ability to control cell damage in blood vessels. "However, in further studies, one might use a combination of therapeutic genes or different gene vectors, for even better results," said Dr. Levy.
Metallic implants are already widely used in medicine. Some examples are artificial joints and orthopedic pins and rods, pacemaker electrodes, and titanium tooth implants. "The results of our study may have broader implications for other diseases in which implantable medical devices may be used to deliver gene therapy," said Dr. Levy.
Dr. Levy's co-authors included Ilia Fishbein, M.D., Ivan S. Alferiev, M.D., Origene Nyanguile, Richard Gaster, and Howard Felderman, of the Children's Hospital Division of Cardiology. Co-authors from the University of Pennsylvania were John M. Vohs and Gordon S. Wong, of the Department of Chemical and Biomolecular Engineering; Hoon Choi and I-Wei Chen, of the Department of Material Science and Engineering; and Robert L. Wilensky, of the Cardiovascular Division of the Hospital of the University of Pennsylvania.