Herein, we report the preparation of temperature-responsive antibody-nanoparticles by the direct polymerization of N-isopropylacrylamide (NIPAAm) from immunoglobulin G (IgG). To this end, a chain transfer agent (CTA) was introduced into IgG, followed by the precipitation polymerization of NIPAAm in an aqueous medium via reversible addition-fragmentation chain transfer polymerization above the lower critical solution temperature (LCST). Consequently, antibody-polymer particles with diameters of approximately 100-200 nm were formed. Owing to the entanglement of the grafted polymers via partial chemical crosslinking, the antibody-nanoparticles maintained their stability even at temperatures below the LCST. Further, the dispersed nanoparticles could be collected by thermal precipitation above the LCST. Additionally, the antibody-nanoparticles formulation could maintain its binding constant and exhibited a good resistance against enzymatic treatment. Thus, the proposed antibody-nanoparticles can be useful for maximizing the therapeutic potential of antibody-drug conjugates or efficacies of immunoassays and antibody recovery and recycling.
Keywords: RAFT; grafting from; polymer–protein conjugates; precipitation polymerization; temperature-responsive.