title: Nanocrystal targeting in vivo.
abstract: Inorganic nanostructures that interface with biological systems have recently attracted widespread interest in biology and medicine. Nanoparticles are thought to have potential as novel intravascular probes for both diagnostic (e.g., imaging) and therapeutic purposes (e.g., drug delivery). Critical issues for successful nanoparticle delivery include the ability to target specific tissues and cell types and escape from the biological particulate filter known as the reticuloendothelial system. We set out to explore the feasibility of in vivo targeting by using semiconductor quantum dots (qdots). Qdots are small (<10 nm) inorganic nanocrystals that possess unique luminescent properties; their fluorescence emission is stable and tuned by varying the particle size or composition. We show that ZnS-capped CdSe qdots coated with a lung-targeting peptide accumulate in the lungs of mice after i.v. injection, whereas two other peptides specifically direct qdots to blood vessels or lymphatic vessels in tumors. We also show that adding polyethylene glycol to the qdot coating prevents nonselective accumulation of qdots in reticuloendothelial tissues. These results encourage the construction of more complex nanostructures with capabilities such as disease sensing and drug delivery.
authors.affiliation: Cancer Research Center, The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Akerman
authors.forename: Warren C W
authors.initials: WC
authors.lastname: Chan
authors.forename: Pirjo
authors.initials: P
authors.lastname: Laakkonen
authors.forename: Sangeeta N
authors.initials: SN
authors.lastname: Bhatia
authors.forename: Erkki
authors.initials: E
authors.lastname: Ruoslahti
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D012157:Mononuclear Phagocyte System / Q000378:metabolism*; D036103:Nanotechnology / Q000379:methods*; D009368:Neoplasm Transplantation; D010455:Peptides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D012666:Semiconductors; D013501:Surface-Active Agents / Q000737:chemistry; D014407:Tumor Cells, Cultured
chemical_list: D010455:Peptides; D013501:Surface-Active Agents; D011092:Polyethylene Glycols