Delivery of Nucleic Acids and Nanomaterials by Cell-Penetrating Peptides: Opportunities and Challenges

Figure 4

(a) Synthesis of water-soluble carboxylated CdSe/ZnS quantum dots. Upon addition of ZnS as a shell to protect Cd core, the surface was modified with 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethyleneglycol)-2000] (DSPE-PEG 2000) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] (PEG-2 PE). The amount and ratio of PEG2-PE and DSPE-PEG(200) determine suspension stability in water. (b) Fluorescence of CdSe/ZnS quantum dot in live cells with (left) and without (right) nona-arginine after a 1-hour exposure [17].

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