Zwitterionic Nanogels Crosslinked by Fluorescent Carbon Dots for Targeted Drug Delivery and Simultaneous Bioimaging.

A zwitterionic multifunctional nanogel drug delivery vehicle was synthesized by copolymerizing ornithine methacrylamide (OrnAA, a newly developed amino acid – derived zwitterionic non-fouling monomer) with fluorescent crosslinkable carbon dots (CCDs). In this construct, the zwitterionic nanogel network served as a functionalizable non-fouling matrix for drug loading, while the introduction of CCDs as crosslinkers enabled the real-time tracking and locating of the nanogel. The nanogels showed exceptional stability when incubated in protein solutions and stable fluorescence similar to that of CCDs. Labeled dextran was encapsulated in nanogels as a model drug, and was released in a controlled manner. Importantly, cellular uptake experiments showed that the folic acid – conjugated nanogels can be specifically internalized by the folate receptor – overexpressed cancer cells, but not in normal tissue cells. This type of multifunctional nanogels holds great potential for targeted delivery and simultaneous imaging in cancer therapy.