Figure 4

PEGylated Quantum Dot (QD) nanocrystals conjugated to ανβ3-specific RGD peptide for endothelial cell targeting; (A) low resolution transmission electron microscopy image showing the nanoconjugates, the arrow indicating one such nanostructure; (B and C) spinning disk confocal microscopy images showing uptake of RGD-targeted QD clusters in endothelial cells treated with cations that are known to cause integrin clustering. Incubation with the RAD-PEG-nanocrystal QD clusters showed no uptake by the cells (B), while RGD-PEG-nanocrystal QD clusters resulted in increased uptake into the cells (C).