Quantum dot-loaded PEGylated poly(alkyl cyanoacrylate) nanoparticles for in vitro and in vivo imaging

Visible- and near-infrared-emitting quantum-dots (QDs) were readily encapsulated with high yields into PEGylated, poly(alkyl cyanoacrylate) nanoparticles (NPs) by self-assembly in aqueous solution. The resulting QD-loaded NPs were efficiently purified and characterized by transmission electron microscopy, dynamic light scattering and ζ-potential measurements as well as by stability studies and cell viability assays. Concomitant encapsulation of different kinds of QDs led to barcode NPs. They were then used for human brain endothelial cell imaging allowing their uptake to be monitored. Finally, the in vivo fate of near-infrared fluorescent NPs was visualized noninvasively by fluorescence optical imaging.