Synthesis of a Functional Metal-Chelating Polymer and Steps toward Quantitative Mass Cytometry Bioassays

摘要

We describe the synthesis and characterization of metalchelatingnpolymers with a degree of polymerization of 67nand 79, high diethylenetriaminepentaacetic acid (DTPA)nfunctionality, Mw/Mn e 1.17, and a maleimide as annorthogonal functional group for conjugation to antibodies.nThe polymeric disulfide form of the DPn ) 79nDTPA polymer was analyzed by thermogravimetricnanalysis to determine moisture and sodium-ion contentnand by isothermal titration calorimetry (ITC) to determinenthe Gd3+ binding capacity. These results showedneach chain binds 68 ( 7 Gd3+ per chain. Secondaryngoat antimouse IgG was covalently labeled with thenmaleimide form of the DTPA polymer (DPn ) 79)ncarrying 159Tb. Conventional ICPMS analysis of thisnconjugate showed each antibody carried an average ofn161 ( 4 159Tb atoms. This result was combined withnthe ITC result to show there are an average of 2.4 (n0.3 polymer chains attached to each antibody. Elevennmonoclonal primary antibodies were labeled with differentnlanthanide isotopes using the same labelingnmethodology. Single cell analysis of whole umbilicalncord blood stained with a mixture of 11 metal-taggednantibodies was performed by mass cytometry.