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

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)-b-poly(ethylene glycol) diblock copolymer (PI-b-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-manno-heptulose, 6-glucose, 6-galactose, 2-deoxy-2-{[methylamino)carbonyl]amino}-o-glucopyranose ("des(nitroso)-streptozotocin"), or 6-maltose, the glycoconjugated QDs showed enhanced affinity constants due to multivalent binding effects. None Of the constructs showed toxicity from 0.001 to 1 mu M (particle concentration) using standard WST and LDH assays on A549 cells.