title: Stimuli-responsive magnetic nanoparticles for monoclonal antibody purification.
abstract: Monoclonal antibodies (mAbs) are important therapeutic proteins. One of the challenges facing large-scale production of monoclonal antibodies is the capacity bottleneck in downstream processing, which can be circumvented by using magnetic stimuli-responsive polymer nanoparticles. In this work, stimuli-responsive magnetic particles composed of a magnetic poly(methyl methacrylate) core with a poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) shell cross-linked with N, N'-methylenebisacrylamide were prepared by miniemulsion polymerization. The particles were shown to have an average hydrodynamic diameter of 317 nm at 18°C, which decreased to 277 nm at 41°C due to the collapse of the thermo-responsive shell. The particles were superparamagnetic in behavior and exhibited a saturation magnetization of 12.6 emu/g. Subsequently, we evaluated the potential of these negatively charged stimuli-responsive magnetic particles in the purification of a monoclonal antibody from a diafiltered CHO cell culture supernatant by cation exchange. The adsorption of antibodies onto P(NIPAM-co-AA)-coated nanoparticles was highly selective and allowed for the recovery of approximately 94% of the mAb. Different elution strategies were employed providing highly pure mAb fractions with host cell protein (HCP) removal greater than 98%. By exploring the stimuli-responsive properties of the particles, shorter magnetic separation times were possible without significant differences in product yield and purity.
authors: Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Technical University of Lisbon, 1049-001 Lisbon, Portugal.
authors: Luís
authors: L
authors: Borlido
authors: Leila
authors: L
authors: Moura
authors: Ana M
authors: AM
authors: Azevedo
authors: Ana C A
authors: AC
authors: Roque
authors: Maria R
authors: MR
authors: Aires-Barros
authors: José Paulo S
authors: JP
authors: Farinha
mesh_terms: D000327:Adsorption; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D007474:Ion Exchange; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D058185:Magnetite Nanoparticles; D011994:Recombinant Proteins