title: Tumor uptake of hollow gold nanospheres after intravenous and intra-arterial injection: PET/CT study in a rabbit VX2 liver cancer model.
abstract: OBJECTIVE
  This study was designed to investigate the intratumoral uptake of hollow gold nanospheres (HAuNS) after hepatic intra-arterial (IA) and intravenous (IV) injection in a liver tumor model.
  
  
  METHODS
  Fifteen VX2 tumor-bearing rabbits were randomized into five groups (n = 3 in each group) that received either IV (64)Cu-labeled PEG-HAuNS (IV-PEG-HAuNS), IA (64)Cu-labeled PEG-HAuNS (IA-PEG-HAuNS), IV cyclic peptide (RGD)-conjugated (64)Cu-labeled PEG-HAuNS (IV-RGD-PEG-HAuNS), IA RGD-conjugated (64)Cu-labeled PEG-HAuNS (IA-RGD-PEG-HAuNS), or IA (64)Cu-labeled PEG-HAuNS with lipiodol (IA-PEG-HAuNS-lipiodol). The animals underwent PET/CT 1 h after injection, and uptake expressed as percentage of injected dose per gram of tissue (%ID/g) was measured in tumor and major organs. The animals were euthanized 24 h after injection, and tissues were evaluated for radioactivity.
  
  
  RESULTS
  At 1 h after injection, animals in the IA-PEG-HAuNS-lipiodol group showed significantly higher tumor uptake (P < 0.001) and higher ratios of tumor-to-normal liver uptake (P < 0.001) than those in all other groups. The biodistribution of radioactivity 24 h after injection showed that IA delivery of PEG-HAuNS with lipiodol resulted in the highest tumor uptake (0.33 %ID/g; P < 0.001) and tumor-to-normal liver ratio (P < 0.001) among all delivery methods. At 24 h, the IA-RGD-PEG-HAuNS group showed higher tumor uptake than the IA-PEG-HAuNS group (0.20 vs. 0.099 %ID/g; P < 0.001).
  
  
  CONCLUSIONS
  Adding iodized oil to IA-PEG-HAuNS maximizes nanoparticle delivery to hepatic tumors and therefore may be useful in targeted chemotherapy and photoablative therapy. PET/CT can be used to noninvasively monitor the biodistribution of radiolabeled HAuNS after IV or IA injection.
authors.affiliation: Department of Experimental Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston, TX, USA, meitian@gmail.com.
authors.forename: Mei
authors.initials: M
authors.lastname: Tian
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Chiyi
authors.initials: C
authors.lastname: Xiong
authors.forename: Joe
authors.initials: J
authors.lastname: Ensor
authors.forename: Javier
authors.initials: J
authors.lastname: Nazario
authors.forename: James
authors.initials: J
authors.lastname: Jackson
authors.forename: Colette
authors.initials: C
authors.lastname: Shaw
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Dixon
authors.forename: Jennifer
authors.initials: J
authors.lastname: Miller
authors.forename: Kenneth
authors.initials: K
authors.lastname: Wright
authors.forename: Chun
authors.initials: C
authors.lastname: Li
authors.forename: Sanjay
authors.initials: S
authors.lastname: Gupta
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006046:Gold / Q000008:administration & dosage / Q000378:metabolism*; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D054118:Nanospheres / Q000378:metabolism*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry; D049268:Positron-Emission Tomography; D011817:Rabbits; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
chemical_list: D009842:Oligopeptides; D011092:Polyethylene Glycols; D006046:Gold; C047981:arginyl-glycyl-aspartic acid