No abstract

A procedure for electroplating a Co/(188)Re alloy layer on metal coils (stents) at room temperature was developed. The electroplating of the Co/(188)Re alloy layer was carried out at a current density of 93 A m(-2) and produced a physically strong Co/(188)Re alloy layer that adhered well to a thin gold strike layer on top of the stent material. The final gold layer was also stable. An empirically-found equation correlates the radioactive electroplating efficiency factor to the concentration of the radioisotope and was used to deposit predetermined amounts of radioactivity on the stent surface. Radioactive stents can be prepared and quality control performed within 2 hours using an automated electroplater and dosimetric quality control system. The radioactivity was homogeneously distributed on the stent surface. The in vitro stability in human plasma at 37 degrees C was found to be greater than 95% for both Wallstent and Ultraflex stent after 72 hours of incubation. A clinical pilot trial is planned after successful completion of animal testing.

Diamond like carbon has been deposited as a protective layer for coronary stenting applications. Taking advantage of DLC's resistance to chemical attack, its flexibility, and other properties. our current technical objective is to develop DLC as a coating for radioactive rhenium stents. Radioactive rhenium stents are being investigated to limit smooth muscle cell growth following coronary surgery. The DLC coating is being investigated to reduce the release of radioactive rhenium (released activity) into the blood following the stenting procedure. An inductively coupled RF plasma system was used to deposit the DLC onto rhenium substrates. Foils, wires, and coils were coated and tested for adhesion, cytotoxicity, and release of radioactive rhenium. Our initial results indicate up to a three-fold decrease in released activity relative to uncoated rhenium