Research Project
2424321
In 1995 about one million people worldwide had fatty blockages in their coronary arteries opened by dilation. This procedure still results in a reclosure of the artery (restenosis) in about 30% of the cases despite the use of a tiny mesh supporting tube (stent) in the artery at the blockage site. Recently the exposure of the stent site to ionizing radiation has shown a marked inhibition of restenosis in animal and human studies. The technique with the lowest radiation dose to the patient is by using the radioisotope phosphorous-32 ion implanted into the stent itself. This isotope produces short-range radiation with a 14 day half-life which only affects the nearest tissues, rather than the entire body. Ion implantation burys the radioisotope below the surface of the stent, providing a safe, sealed product for the medical team handling the stent. Even though the FDA has authorized a 1200 patient study of the effects of phosphorous-32 ion implanted stents, no production facility presently exists in the U.S. to do the implantation. There are special safety hazards in generating radioactive ion beams using the techniques previously employed. We propose an innovative type of radioactive phosphorous source which consists of a sealed solid disk. Successful completion of Phase I and Phase II will produce a low cost technique to safely mass produce radioactive stents that will significantly improve the long term success rate of coronary angioplasty. PROPOSED COMMERCIAL APPLICATION This research will lead to the high volume ion implantation of coronary stents with radioactive P-32. Radioactive stents have been shown to markedly reduce restenosis after arthroplasty. Implant Sciences Corporation plans to offer the ion implantation as a service to stent manufactures.
