title: Cellular uptake and transport of gold nanoparticles incorporated in a liposomal carrier.
abstract: Recent interest in using gold nanoparticles (Au NPs) for therapy in radiation medicine has motivated development of a liposome-based system to enhance their delivery to cells. In this study, liposomes were demonstrated to perform like a "Trojan Horse" to deliver small (1.4 nm) Au NPs into tumor cells by overcoming the energetically unfavorable endocytosis process for small NPs. The results reveal that the liposomal approach provides a thousand-fold enhancement in the cellular uptake of the small Au NPs. Real-time intracellular tracking of the Au NP-liposomes revealed an average speed of 12.48 +/- 3.12 microm/hr for their intracellular transport. Analysis of the time-dependent intracellular spatial distribution of the Au NP-liposomes demonstrated that they reside in lysosomes (final degrading organelles) within 40 minutes of incubation. Knowledge gained in these studies opens the door to pursuing liposomes as a viable strategy for delivery of Au NPs in radiation therapy applications.
  
  
  BACKGROUND
  Gold nanoparticles (Au NPs) as part of an optimized liposome-based delivery system have been proposed for therapy in radiation medicine. The approach resulted in a thousand-fold enhancement in the cellular uptake of Au NPs compared to conventional delivery methods, with the nanoparticles residing in lysosomes within 40 minutes of incubation.
authors.affiliation: Department of Radiation Physics, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada. devika.chithrani@rmp.uhn.on.ca
authors.forename: Devika B
authors.initials: DB
authors.lastname: Chithrani
authors.forename: Michael
authors.initials: M
authors.lastname: Dunne
authors.forename: James
authors.initials: J
authors.lastname: Stewart
authors.forename: Christine
authors.initials: C
authors.lastname: Allen
authors.forename: David A
authors.initials: DA
authors.lastname: Jaffray
mesh_terms: D001692:Biological Transport; D004337:Drug Carriers / Q000737:chemistry*; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D006046:Gold / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008081:Liposomes; D008247:Lysosomes / Q000378:metabolism; D053768:Metal Nanoparticles / Q000032:analysis* / Q000648:ultrastructure; D013052:Spectrometry, X-Ray Emission
chemical_list: D004337:Drug Carriers; D008081:Liposomes; D006046:Gold