Methods for radiolabeling synthetic polymers

A method of radiation therapy of a patient, the method comprising administering to an artery of said patient a medical device of a size range that, upon arterial administration, is capable of being entrapped in an arterial blood vessel network of a tissue and that comprises at least one microsphere, bead, capsule, microparticle, fibre, rod, filament, membrane, wafer, mesh, gauze, porous sponge, tube or stent, said medical device having incorporated therein or thereon a therapeutically effective amount of a radiolabeled synthetic polymer,

• wherein said radiolabeled synthetic polymer comprises a synthetic polymer complexed with a carbon encapsulated nanoparticle composite having a radioactive particulate core,
• wherein the carbon encapsulated nanoparticle composite is a carbon encapsulated 99mTc, 113mIn, 111In, 198Au, 64Cu, 213Bi, 57Co, 51Cr, 165Dy, 169Er, 59Fe, 153Gd, 166Ho, 177Lu, 103Pd, 81Rb, 82Rb, 186Re, 188Re, 75Se, 153Sm, 117mSn, 89Sr, 201Tl, 90Y or 169Yb nanoparticle having a diameter of 10 to 500 nanometers;
• wherein the synthetic polymer is polystyrene, polypropylene, polytetrafluorethylene (PTFE), expanded polytetraflourethylene (EPTFE), polyurethane, polyvinyl chloride, polyamides, polystyrene sulphonate, polyester, polyethylene terephthalate (PET), poly(butylene terephthalate) (PBT), poly(ethylene oxide) (PEO), polylactide (PLA), polyglycolide (PGA), poly(lactide-co-glycolide) (PLGA), poly(e-caprolactone), polydioxanone, trimethylene carbonate, polyanhydride, or poly[bis(p-carboxyphenoxyl)propane:sebacic acid;
• and
• wherein said radiolabeled synthetic polymer is prepared in an aqueous medium comprising (i) at least one of a polycation or an anionic surfactant;
• and (ii) an electrolyte concentration or a pH that is selected to promote in the aqueous medium short-range attractive forces between the carbon encapsulated nanoparticle and the synthetic polymer by attenuating long-range electrostatic repulsive forces so that the carbon encapsulated nanoparticle and the synthetic polymer comprise a complex that is stable under in vivo conditions in a mammal.