Sorption of 223Ra and 211Pb on modified nanodiamonds for potential application in radiotherapy.

²²³Ra and ²¹¹Pb/²¹¹Bi radionuclides with radiochemical purity were obtained from ²²⁷Ac/²²³Ra generator on DGA resin. Covalent grafting of organic complexons (ethylenediaminetetraacetic acid—EDTA and derivatives of amino acids—L1 and L2 to aminated nanodiamonds (ND) was performed by carbodiimide method. Adsorption behavior of Ra and Pb in plasma volume expander on modified nanodiamonds was studied in detail. Effective adsorption have been found for ²¹¹Pb in physiologically acceptable conditions. Sorption behavior of generator radionuclides ²²³Ra and ²¹¹Pb on the surface of ND-L1 and ND-L2 in aqueous solution (pH = 6.3) was studied. It was shown that the labeling yield of ²¹¹Pb from the solution was about 94%. The sorption of ²²³Ra under the same conditions was weak. The sorption/desorption kinetics of ²¹¹Pb on the surface of ND-EDTA in the plasma volume expander was studied. The desorption rate of ²¹¹Pb did not exceed 2.5% within 60 min (pH 7.2-7.4). [ABSTRACT FROM AUTHOR]