2026-10-14T16:39:44Z https://www.scidb.cn/oai

10.57760/sciencedb.0108u 2026-08-26T13:44:36Z

2026-08-26 Labeling of DOTA and DOTA-Substance P with bismuth radioisotopes in solution and cross-linked dextran medium doi:10.57760/sciencedb.0108u en The labeling of H4DOTA (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetracetic acid) and H4DOTA-substance P with 207Bi in a cross-linked dextran medium and an aqueous solution was compared. The thermodynamic and kinetic parameters for DOTA complexation with Bi³⁺ were determined, and the apparent stability constant of 29.3 ± 0.4, obtained by the competitive sorption method, was consistent with literature data. It was demonstrated that cross-linked dextran could be used as a suitable medium for determining stability constants for Bi³⁺ complexes. The stability of the 207Bi-DOTA complex formed at different temperatures was monitored over time in the presence of excess EDTA using UV spectrophotometry.A method for producing a labeled bioconjugate, 213Bi-DOTA-substance P, using a 225Ac/213Bi generator-synthesis module was developed. The presence of the cross-linked dextran medium did not affect the kinetics of radiolabeling, although the yield of the labeled bioconjugate slightly decreased (from 92% to 85%). In vitro stability of the bioconjugate obtained in the dextran medium is identical to that synthesized in solution. The radiopharmaceutical can be obtained with high radiochemical purity (>98%), eliminating the need for additional purification steps and reducing synthesis time. Alpha-emitters; Ac-225/Bi-213; Circulating generator; Bi-213 Radioimmunoconjugate; DOTA; Substance P. Aleksandr Vasiliev PUBLIC https://creativecommons.org/licenses/by/4.0/ dataset Science Data Bank