Experimental Stent Coating May Deliver Gene Therapy
Method could be useful for treating in-stent restenosis
WEDNESDAY, Dec. 21 (HealthDay News) -- An experimental coating for metallic stents can deliver genes to blood vessels and may be useful for treating arterial restenosis with gene therapy, according to a study published online Dec. 21 in the Proceedings of the National Academy of Sciences Early Edition.
Robert J. Levy, M.D., and colleagues at the University of Pennsylvania in Philadelphia, synthesized a polyallylamine bisphosphonate (PAA-BP) coating and applied it to steel, nitinol or cobalt-chromium metal alloy surfaces. They then attached an adenovirus vector for gene therapy to the coating via an antibody or an adenovirus-binding protein.
PAA-BP adenovirus-coated metal stents were effective in delivering a test compound, green fluorescent protein, to cultures of smooth muscle cells and to the arterial wall of rats after carotid angioplasty. The researchers also found that adenoviruses that produced inducible nitric oxide synthase could be attached to coated stents, and block restenosis in rats. There was a neointimal/media ratio of 1.7 for coated stents containing adenovirus and 3.4 for control stents.
"This metal-bisphosphonate-coordination complex has been demonstrated in the present studies to enable the covalent attachment of vector-binding agents for therapeutic gene delivery to the arterial wall," Levy and colleagues conclude. "Because of the widespread use of metallic implants in medicine, these results have broad implications for a therapeutic approach involving implantable medical devices configured with gene-therapy constructs."