title: Biotinylated thermoresponsive core cross-linked nanoparticles via RAFT polymerization and "click" chemistry.
abstract: A straightforward approach to the synthesis of "clickable" thermoresponsive core cross-linked (CCL) nanoparticles was developed. This approach was based on reversible addition-fragmentation chain transfer (RAFT) radical cross-linking polymerization of styrene and divinylbenzene with azide-functionalized poly(N-isopropylacrylamide) (PNIPAM-N(3)) as macro chain transfer agent in a selective solvent. Spherical nanoparticles with a diameter of 12nm were obtained after 24h polymerization. When the lyophilized CCL nanoparticles were dispersed in THF, spherical nanoparticles were observed, confirming the stability of CCL nanoparticles. The transmission electron microscopy (TEM) studies demonstrated that spherical nanoparticles and wormlike structure coexisted in the aqueous solution. The CCL nanoparticles have a lower critical solution temperature (LCST) at about 29.6°C, a little lower than that of PNIPAM homopolymer. Biotin molecules were conjugated to the surface of CCL nanoparticles via "click" chemistry in aqueous media. After bioconjugation, the LCST shifted to 28.3°C. The bioavailability of biotin to protein avidin was evaluated by a 4'-hydroxyazobenzene-2-carboxylic acid/avidin (HABA/avidin) binding assay and TEM.
authors.affiliation: Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, Nankai University, Tianjin, PR China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Lv
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Wang
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001360:Avidin / Q000737:chemistry / Q000378:metabolism*; D001391:Azo Compounds / Q000737:chemistry; D001710:Biotin / Q000737:chemistry / Q000378:metabolism*; D019921:Biotinylation / Q000379:methods; D057930:Click Chemistry; D003432:Cross-Linking Reagents / Q000138:chemical synthesis; D005612:Freeze Drying; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D058105:Polymerization; D020058:Styrene / Q000737:chemistry; D013696:Temperature; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D001391:Azo Compounds; D003432:Cross-Linking Reagents; D014753:Vinyl Compounds; D001360:Avidin; C001413:HABA; C052970:poly-N-isopropylacrylamide; D020058:Styrene; D001710:Biotin; C004985:divinyl benzene