title: Application of polymeric macroporous supports for temperature-responsive chromatography of pharmaceuticals.
abstract: A macroporous particulate support prepared previously by reactive gelation under shear and functionalized with poly(N-isopropylacrylamide), PNIPAM, brushes of variable length is applied for temperature-responsive chromatography, whereby temperature modulates hydrophobic interactions. Several different analytes, including small pharmaceuticals, peptides, proteins and monoclonal antibodies are employed. Contrary to the most commonly observed behavior in conventional chromatography, increasing retention is observed at elevated temperatures. Peak broadening is quantified using the peak standard deviation, which depends on both the polymer chain conformation and analyte adsorptivity. The favorable effect of grafted polymer thickness on retention becomes progressively less pronounced for thicker grafted PNIPAM layers. The effect of eluent composition on solute-sorbent interactions was investigated by introducing NaCl, methanol, dioxane and by varying the pH. Salt or organic solvent addition affects apart from the analytes solution properties, the hydrophobicity of the stationary phase itself. Frontal analyses performed at different temperatures to determine dynamic binding capacities, indicate small mass transfer resistances imposed by this novel packing material.
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Lamprou
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland; Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: Agni-Faviola-Mika
authors.initials: AF
authors.lastname: Gavriilidou
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Storti
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland; Department of Chemical Engineering, University of Chemistry and Technology, Technicka 5, 166 28 Prague, Czech Republic. Electronic address: miroslav.soos@chem.ethz.ch.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Soos
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland. Electronic address: massimo.morbidelli@chem.ethz.ch.
authors.forename: Massimo
authors.initials: M
authors.lastname: Morbidelli
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods*; D002845:Chromatography; D057927:Hydrophobic and Hydrophilic Interactions; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013696:Temperature
chemical_list: D004364:Pharmaceutical Preparations; D012996:Solutions
keywords: ATRP; Analyte retention factor; Conformational transition; Frontal analysis; Grafted brushes; Hydrophobic interactions; LCST; Macroporous particles; Monoclonal antibodies; Perfusion; Poly(N-isopropylacrylamide); Reactive gelation; Standard deviation; Steroids; Temperature-responsive chromatography