Stimuli-Responsive Polymer-Antibody Conjugates via RAFT and Tetrafluorophenyl Active Ester Chemistry

Highly efficient polymer-antibody conjugations were demonstrated via a tetrafluorophenyl active ester. A well-defined diblock copolymer was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization with a temperature-responsive block, poly(N-isopropylacrylamide), and a block of N,N-dimethylacrylamide and 2,3,5,6-tetrafluorophenyl acrylate active ester. The polymer was conjugated to anti-p24 IgG antibody with about 100% efficiency in as little as 2 h at room temperature in a pH 10.8 buffer. The temperature-responsiveness of the polymer was conferred to the polymer-antibody conjugates after conjugation. The conjugates bound p24 antigen specifically and with binding efficiency comparable to native antibodies. Thus, the active ester diblock copolymer can facilitate the synthesis of temperature-responsive bioconjugates, which may be promising reagents for immunoassays, bioseparations, and specimen-enrichment applications.