Encapsulation of isotope on novel beta-emitting poly(ethylene terephthalate) surfaces.
Recent data indicate that intravascular betaa-irradiation from centrally located sources at the time of balloon angioplasty or stenting reduces proliferation of smooth muscle cells, neointima formation, and restenosis. In an effort to simplify radiation delivery, a novel beta-radiation source was developed based on the adsorption of 32P (phosphoric acid) by pH-sensitive chitosan hydrogel on a poly(ethylene terephthalate) balloon surface. To prevent the 32P-isotope desorption in the patient's blood, the adsorbed phosphoric acid was precipitated as CaHPO4 on the surface by a saturated Ca(OH)2/5% CaCl2 solution. Various polyurethanes were applied to seal the radioactive surface by the dip-coating method. The isotope off-rate results were determined. Optimal results were obtained by serially coating with two polyurethane solutions. This approach holds promise for simplifying and improving the safety, and minimizing the cost of intravascular brachytherapy.
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Department of Medicine, Interventional Cardiology Center, Columbia University, 161 Fort Washington Avenue, AP-551, New York, New York 10032, USA.
Weinberger
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J
D000327:Adsorption; D000800:Angioplasty, Balloon / Q000379:methods; D001610:Beta Particles; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry*; D048271:Chitosan; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D007212:Indolizines; D008854:Microscopy, Electron; D010756:Phosphoric Acids / Q000737:chemistry; D010761:Phosphorus Radioisotopes / Q000737:chemistry / Q000378:metabolism*; D011093:Polyethylene Terephthalates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013876:Thiophenes
C092798:ADT 16; D020100:Hydrogels; D007212:Indolizines; D010756:Phosphoric Acids; D010761:Phosphorus Radioisotopes; D011093:Polyethylene Terephthalates; D013876:Thiophenes; D002686:Chitin; D048271:Chitosan; C030242:phosphoric acid