Glycoconjugated Amphiphilic Polymers via Click-Chemistry for the Encapsulation of Quantum Dots

Abstract

Herein, we present a strategy for the glycoconjugation of nanoparticles (NPs), with a special focus on fluorescent quantum dots (QDs), recently described by us as “preassembly” approach. Therein, prior to the encapsulation of diverse nanoparticles by an amphiphilic poly­(isoprene)-<i>b</i>-poly­(ethylene glycol) diblock copolymer (PI-<i>b</i>-PEG), the terminal PEG appendage was modified by covalently attaching a carbohydrate moiety using Huisgen-type click-chemistry. Successful functionalization was proven by NMR spectroscopy. The terminally glycoconjugated polymers were subsequently used for the encapsulation of QDs in a phase transfer process, which fully preserved fluorescence properties. Binding of these nanoconstructs to the lectin Concanavalin A (Con A) was studied via surface plasmon resonance (SPR). Depending on the carbohydrate moiety, namely, d-<i>manno</i>-heptulose, d-glucose, d-galactose, 2-deoxy-2-{[methylamino)­carbonyl]­amino}-d-glucopyranose (“des­(nitroso)-streptozotocin”), or d-maltose, the glycoconjugated QDs showed enhanced affinity constants due to multivalent binding effects. None of the constructs showed toxicity from 0.001 to 1 μM (particle concentration) using standard WST and LDH assays on A549 cells