32P Carriers Based on Hydroxyapatite-Modified Alginate Beads

Abstract 32 P carriers based on calcium alginate and hydroxyapatite for potential application in nuclear medicine were studied. Alginate beads cross-linked with calcium and mineralized with nanocrystalline hydroxyapatite were synthesized. The samples were characterized by optical and electron microscopy, X-ray diffraction, and IR spectroscopy. The KH 2 [ 32 P]O 4 sorption from an aqueous solution was proposed as a method for introducing radionuclides into alginate beads. The kinetics of this process and the effect of mineralization and swelling of the hydrogel in an aqueous medium and in saline were studied. Composite calcium alginate and hydroxyapatite beads took up 90% of the activity from a saline solution within 5 h. Mineralization with hydroxyapatite improved both the kinetic parameters of sorption and the retention of the radionuclide in an aqueous medium. Composite calcium alginate and hydroxyapatite beads can be recommended for further tests as applicator materials for surface brachytherapy with 32 P.