Description: Research Plans: The successful development of Cu-64 radiopharmaceuticals depends upon retention of the Cu-64 atom in the radiopharmaceutical. To date, the focus has been on the development of chelators that better retain Cu-64, but there has been no effort to develop an effective method by which improved retention may be measured. In the absence of a suitable analytical method, the stability of Cu-64 radiopharmaceuticals is estimated indirectly, with decreased liver uptake suggesting higher in vivo complex stability. But this approach is inadequate for radiopharmaceuticals, such as radiolabeled antibodies, that are expected to accumulate in the liver even when there is no free Cu-64 present. The absence of such a method has also hampered efforts to systematically evaluate the chemical factors that may give rise to improved retention. The objective of this project is to develop and validate such a method. Accomplishments: The two primary accomplishments of this project will be 1) the development and validation of a method to measure the stability of Cu-64 radiopharmaceuticals and 2) the determination of the chemical factors that define the in vivo stability of Cu 64 radiopharmaceuticals. Because Cu(II) is extremely labile, the in vivo stability of Cu-64 radiopharmaceuticals is not primarily determined by the amount of ÃÂ¢ÃÂÃÂfreeÃÂ¢ÃÂÃÂ Cu that is present at any given time or by the thermodynamic stability constants, but rather by the rate at which Cu is lost from the complex, the dissociation rate constant, kd. The dissociation rate constants of the Cu-64 complexes from a series of bifunctional chelators (BFCs) will be measured using Free Ion Selective Radiotracer Extraction (FISRE), a technique originally developed to measure bioavailable Cu in environmental samples. FISRE will also be applied to the determination of the kdÃÂ¢ÃÂÃÂs of a series of reference Cu-64 complexes to determine the chemical factors that define the in vivo ...
Date: December 15, 2011
Creator: Packard, Alan B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department