Functionalized, Biocompatible Coating for Superparamagnetic Nanoparticles by Controlled Polymerization of a Thioglycosidic Monomer

Abstract

It is demonstrated that water-soluble, glucosylated poly(pentafluorostyrene) derivatives revealed favorable coating material properties for magnetic iron oxide nanoparticles. To prepare the coating material in high reproducibility and purity as well as in sufficient amounts, a new route of synthesis is established. The preparation and characterization of the glucosylated, tetrafluorostyryl monomer, by thiol-para-fluorine "click" reaction, and its polymerization, via nitroxide-mediated radical process, is presented in detail. In addition, the coating material and the resulting particle properties are investigated by means of XPS, DLS, TGA, TEM, and cryo-TEM as well as flow cytometry. The glycopolymer acts as an appropriate stabilizing agent for the superparamagnetic nanoparticles by the formation of an approximately 10 nm thick shell, as shown by the XPS analysis. Furthermore, the application of FITC-labeled glycopolymer yielded fluorescent, superparamagnetic nanoparticles, which can be used for monitoring cell-carbohydrate interactions, because these particles show no cytotoxicity toward 3T3 fibroblasts.

Convergent diversity-oriented side-chain macrocyclization scan for unprotected polypeptides

“…14 We and others have recently become interested in a formerly unrecognized reaction between thiol nucleophiles and activated perfluoroaromatic molecules. 15 This reaction satisfies several important prerequisites of being a “click” transformation (Figure 2a). 14,15 Our recent study showed one can use two commercially available perfluoroaromatic reagents (Figure 2b, L a and L b ) to cross-link two cysteine moieties positioned in the i , i+4 fashion within a polypeptide.…”

Heterofunctionalized Multiarm Star Polymers via Sequential Thiol-para-Fluoro and Thiol-Ene Double “Click” Reactions

“…Moreover, it is well known that the labile para ‐fluorine substituents of pentafluorophenyl groups can undergo nucleophilic substitution reactions particularly with thiol‐based nucleophiles even at room temperature . Recently, Schubert and co‐workers employed thiol‐ para‐ fluoro “click” reaction to obtain glycopolymers at low temperature to prevent degradation of sugar units . Although it is mainly a nucleophilic substitution reaction, the versatility and efficiency of thiol substitution of the para ‐fluoro group has been demonstrated by Schubert et al to follow with most of the‘‘click” chemistry requirements …”

Glycopolymeric Materials for Advanced Applications

“…One step further described in literature is the preparation of magnetic nanoparticles covered with FITC-labeled glycopolymer yielded fluorescent [81,82]. In these publications the visualization of the nanoparticles by fluorescence imaging is studied, but the possibility of application in magnetic resonance imaging (MRI) is also opened.…”