title: Catechol-initiated polyethers: multifunctional hydrophilic ligands for PEGylation and functionalization of metal oxide nanoparticles.
abstract: Bifunctional CA-PEG (catechol-poly(ethylene glycol)) and multifunctional CA-PEG-PGA/PEVGE (poly(glycidyl amine)/poly(ethylene glycol vinyl glycidyl ether)) ligands for the functionalization and solubilization of nanoparticles are introduced. Tunable polymers with polydispersities <1.25 and molecular weights in the range 500-7700 g mol(-1) containing a catechol moiety for conjugation to metal oxide nanoparticles were prepared. The functional PEG ligands were synthesized starting from the acetonide-protected catechol initiator 2,2-dimethyl-1,3-benzodioxole-5-propanol (CA-OH) for oxyanionic polymerization. CA-OH was used both for homopolymerization of ethylene oxide (EO) as well as copolymerization with functional epoxides N,N-diallyl glycidyl amine (DAGA), releasing primary amino groups and ethylene glycol vinyl glycidyl ether (EVGE), exhibiting a double bond for click-type reactions, to generate CA-PEG and CA-PEG-PGA/PEVGE. We demonstrate the potential of the functional ligands by binding to MnO nanoparticles, rendering the PEGylated nanoparticles highly stable in aqueous environment. Furthermore, addressability of the functional groups has been proven, for example, by coupling with fluoresceine isothiocyanate (FITC), to allow for optical monitoring of the nanoparticle fate in biological systems.
authors.affiliation: Departments of Organic Chemistry, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany.
authors.forename: Valerie S
authors.initials: VS
authors.lastname: Wilms
authors.forename: Heiko
authors.initials: H
authors.lastname: Bauer
authors.forename: Christine
authors.initials: C
authors.lastname: Tonhauser
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Schilmann
authors.forename: Marc-Christian
authors.initials: MC
authors.lastname: Müller
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Tremel
authors.forename: Holger
authors.initials: H
authors.lastname: Frey
mesh_terms: D002396:Catechols / Q000032:analysis / Q000737:chemistry*; D004852:Epoxy Compounds / Q000032:analysis / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D053768:Metal Nanoparticles / Q000032:analysis / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002396:Catechols; D004852:Epoxy Compounds; D008024:Ligands; D011092:Polyethylene Glycols; C034221:catechol