Catechol-Initiated Polyethers: Multifunctional Hydrophilic Ligands for PEGylation and Functionalization of Metal Oxide Nanoparticles

• Published in: Biomacromolecules Vol. 14; no. 1; pp. 193 - 199
• Main Authors: Wilms, Valerie S, Bauer, Heiko, Tonhauser, Christine, Schilmann, Anna-Maria, Müller, Marc-Christian, Tremel, Wolfgang, Frey, Holger
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14.01.2013
• Subjects: Applied sciences; Catechols - analysis; Catechols - chemistry; Epoxy Compounds - analysis; Epoxy Compounds - chemistry; Exact sciences and technology; Hydrophobic and Hydrophilic Interactions; Ligands; Metal Nanoparticles - analysis; Metal Nanoparticles - chemistry; Organic polymers; Physicochemistry of polymers; Polyethylene Glycols - chemistry; Polyethylene Glycols - metabolism; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; Ring opening polymerization; Nanoparticle; Telechelic polymer; Deprotection; Manganese II Oxides; Ethylene oxide copolymer; Experimental study; Oxygen heterocycle; Functional polymer; Allylic compound; Primary alcohol; Ethylene oxide polymer; Chemical modification; Cyclic ether copolymer; Preparation; Anionic catalyst; Diblock copolymer; Hydroxyl group; Anionic polymerization; Anionic copolymerization; Chemical synthesis; Ring opening copolymerization; Amine copolymer; Aliphatic copolymer
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm3015889

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.