Synthesis and evaluation of a water-soluble polymer to reduce Ac-225 daughter migration

NUCL 108

Jonathan M. Fitzsimmons, jmfit@lanl.gov, Los Alamos National Laboratory, Los Alamos, NM 87544 and Robert Atcher, ratcher@lanl.gov, Bioscience Div, Los Alamos National Laboratory, MS E529, Los Alamos, NM 87545.
Alpha emitters show promise for the treatment of diseases. Alpha particles combine high cytotoxicity with an irradiation range of only a few cells. The Ac-225 decay chain has multiple alpha emissions, thus offering the promise of increased cytotoxicity. However daughter nuclei have a recoil energy of about 100 keV which is sufficient to break chemical bonds and damage the primary chelate construct. The development of a water-soluble polymer with primary and various secondary chelator groups designed to coordinate Ac-225 and reduce the migration of daughter nuclei from the targeting moiety has been explored. Actinium-225 radiolabelling of a polymer followed by reactions with either carboxylic derivatives were used to synthesize a radiolabelled polymer with secondary chelators. The Actinium-225 radiolabelled polymer derivatives were found to retain radioactive daughters better than an Actinium-225 labeled directly to a targeting molecule. This synthetic approach used to make Actinium-225 radiolabelled polymers with cancer targeting groups will be discussed.
 

Recent Advances in Molecular Imaging
1:25 PM-4:50 PM, Thursday, 14 September 2006 Moscone Center -- Room 270, Oral

Division of Nuclear Chemistry & Technology

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006