Modification of polymer surfaces as radioisotope carriers

摘要

A radioactive source is made by forming a polymer layer substantially free of inorganic polymers on a substrate material, and exposing the polymer layer to a radioactive isotope. The source is useful for inhibition of restenosis in coronary arteries after balloon angioplasty or stent implantation. In particular, a radioactive source of ³²P, ⁹⁰Y, or ¹⁴⁴Ce is deposited on a poly(ethylene terephtalate) (PET) substrate. The polymer substrate was first coated with pH-sensitive hydrogel and then adsorbed various amount of phosphoric acid (PA) in aqueous solutions. The substrate was immersed in ³²P, ⁹⁰YCl₃ or ¹⁴⁴CeCl₃ solutions, and then ³²P, ⁹⁰Y or ¹⁴⁴Ce was deposited on the surface as ³²PPO₄, ⁹⁰YPO₄ or ¹⁴⁴Ce PO₄. Two different polyurethanes were used to encapsulate and seal the deposited isotopes on the surface to minimize the leakage of the isotope.