RATIONAL AND OBJECTIVES: The authors describe the magnetic resonance imaging (MRI) of a tumor in a nude mouse tumor model by means of an antibody-polylysine (Gd-DTPA) conjugate. METHODS: The monoclonal antibody, (MAB) RA96, was coupled to a polymeric gadolinium complex after periodate oxidation. This polymer, which consists of a polylysine backbone and complexing DTPA subunits, complexes an average of 65 gadolinium ions. RESULTS: The immunoreactivity of the conjugates was reduced by an average of only 30% compared with the unbound MAB RA96. Biodistribution studies in nude mice with subcutaneously implanted human colon carcinomas (WiDr [specific] and HT29 [control]) revealed a tissue concentration in the specific tumor of 8.72% of the dose applied per gram despite the high molecular weight of the conjugates. CONCLUSIONS: This tissue concentration is sufficient to achieve tumor-specific signal enhancement in the WiDr tumor on MRI. The problem of the high doses of protein required for MRI and possible solutions are discussed.
RATIONAL AND OBJECTIVES: The authors describe the magnetic resonance imaging (MRI) of a tumor in a nude mousetumor model by means of an antibody-polylysine (Gd-DTPA) conjugate. METHODS: The monoclonal antibody, (MAB) RA96, was coupled to a polymeric gadolinium complex after periodate oxidation. This polymer, which consists of a polylysine backbone and complexing DTPA subunits, complexes an average of 65 gadolinium ions. RESULTS: The immunoreactivity of the conjugates was reduced by an average of only 30% compared with the unbound MAB RA96. Biodistribution studies in nude mice with subcutaneously implanted humancolon carcinomas (WiDr [specific] and HT29 [control]) revealed a tissue concentration in the specific tumor of 8.72% of the dose applied per gram despite the high molecular weight of the conjugates. CONCLUSIONS: This tissue concentration is sufficient to achieve tumor-specific signal enhancement in the WiDr tumor on MRI. The problem of the high doses of protein required for MRI and possible solutions are discussed.
Authors: Barjor Gimi; Arvind P Pathak; Ellen Ackerstaff; Kristine Glunde; Dmitri Artemov; Zaver M Bhujwalla Journal: Proc IEEE Inst Electr Electron Eng Date: 2005-04-01 Impact factor: 10.961