Obtaining of Nanodiamond Conjugates with Scandium Isotopes for the Use in Nuclear Medicine

In this work, we studied the sorption of scandium, whose isotopes ⁴⁴Sc and ⁴⁷Sc are explored for diagnostics and therapy in nuclear medicine, by aggregates of commercial (TAN, STP) and oxidized nanodiamonds (ox-STP) from aqueous solutions. The sorption capacity of the studied NDs for scandium was determined; 100 μg of NDs is found to be sufficient for the sorption of 1 GBq of ⁴⁷Sc, which is equivalent to the activity of isotopes used in therapy. It was shown that the supposed mechanism for the binding of Sc(III) to nanodiamond aggregates is chemisorption, and the chemical composition of the nanodiamond surface affects the sorption efficiency to a greater extent than the speciation of scandium in solution. The obtained data on Sc(III) sorption are correlated with the sizes of nanodiamond aggregates; it is shown that sorption under experimental conditions does not depend on the size of the aggregates. For the further development of radiopharmaceuticals based on ⁴⁷Sc, optimal carriers for this isotope—TAN and ox-STP—were suggested.