@article {5793,
	title = {Stimuli-Responsive magnetic nanoparticles for monoclonal antibody purification},
	journal = {Biotechnology Journal},
	volume = {8},
	year = {2013},
	pages = {709{\textendash}717},
	abstract = {<p>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{\textquoteright}-methylenebisacrylamide were prepared by miniemulsion polymerization. The particles were shown to have an average hydrodynamic diameter of 317 nm at 18{\textdegree}C, which decreased to 277 nm at 41{\textdegree}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.</p>
},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/biot.201200329/full},
	author = {Lu{\'\i}s Borlido and Leila Moura and Ana M Azevedo and Roque, Ana C A and Maria R Aires-Barros and Jos{\'e} Paulo S Farinha}
}
