title: Polymer nanoparticles covered with phosphorylcholine groups and immobilized with antibody for high-affinity separation of proteins.
abstract: Novel polymer nanoparticles were prepared for the selective capture of a specific protein from a mixture with high effectiveness. The nanoparticle surface was covered with hydrophilic phosphorylcholine groups and active ester groups for easy immobilization of antibodies. Phospholipid polymers (PMBN) composed of 2-methacryloyloxyethyl phosphorylcholine, n-butyl methacrylate, and p-nitrophenyloxycarbonyl polyethyleneglycol methacrylate, were synthesized for the surface modification of poly( l-lactic acid) nanoparticles. Surface analysis of the nanoparticles using laser-Doppler electrophoresis and X-ray photoelectron spectroscopy revealed that the surface of nanoparticles was covered with PMBN. Protein adsorption was evaluated with regard to the nonspecific adsorption on the nanoparticles that was effectively suppressed by the phosphorylcholine groups. The immobilization of antibodies on nanoparticles was carried out under physiological conditions to ensure specific binding of antigens. The antibody immobilized on the nanoparticles exhibited high activity and strong affinity for the antigen similar to that exhibited by an antibody in a solution. The selective binding of a specific protein as an antigen from a protein mixture was relatively high compared to that observed with conventional antibody-immobilized polymer nanoparticles. In conclusion, nanoparticles having both phosphorylcholine and active ester groups for antibody immobilization have strong potential for use in highly selective separation based on the biological affinities between biomolecules.
authors.affiliation: Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8586, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Goto
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Matsuno
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Konno
authors.forename: Madoka
authors.initials: M
authors.lastname: Takai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ishihara
mesh_terms: D000327:Adsorption; D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000737:chemistry; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D009578:Nitrobenzenes / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D011091:Polyesters; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*
chemical_list: C528057:4-nitrophenyloxycarbonyl-polyethyleneglycol; D000906:Antibodies; D000936:Antigen-Antibody Complex; D008689:Methacrylates; D009578:Nitrobenzenes; D010743:Phospholipids; D011091:Polyesters; D011108:Polymers; D011506:Proteins; C513779:poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate-co-p-nitrophenyloxycarbonyl polyethyleneglycol methacrylate); D010767:Phosphorylcholine; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide); C070638:2-methacryloyloxyethyl phosphorylcholine; C016284:butyl methacrylate