Barium ferrite nanoparticles labeled with 223Ra: a new potential radiobioconjugate for internal alpha therapy

Abstract

Alpha particle emitting isotopes are in considerable interest for radionuclide therapy because of their high cytotoxicity and short path length. Unfortunately, many available emitters have certain disadvantages: 211At forms weak bonds with carbon atoms in the biomolecules, 212Bi, 213Bi, 211Pb and 226Th have short half-lives and the decay of 225Ac and 223Ra produces further alpha emitting radionculides that may escape from the radiobioconjugates. An advantage of 223Ra is that it currently has a higher availability. It is obtained from 227Ac/223Ra generators, wherein 227Ac (T1/2=21.8 y) can be produced in research reactors by neutron irradiation of 226Ra targets. Unfortunately, the lack of an appropriate bifunctional ligand for radium has to date hampered the application of 223Ra in receptor targeted therapy. In our studies we investigated barium ferrite (BaFe12O19) bioconjugates as vehicles for 223Ra radionuclide for targeted α therapy.