title: In vivo imaging of sentinel nodes using fluorescent silica nanoparticles in living mice.
abstract: OBJECTIVE
  We examine the feasibility of fluorescent imaging system for sentinel lymph node detection by using functionalized silica nanoparticles.
  
  
  METHODS
  We developed a functionalized RITC-SiO(2) nanoparticles containing fluorescent dye, C(28)H(31)N(2)O(3)Cl (rhodamine B isothiocyanate) inside, and subsequently synthesized (68)Ga-NOTA-RITC-SiO(2) nanoparticles.
  
  
  RESULTS
  At 5 min after RITC-doped silica nanoparticles injection, fluorescent signals were shown in both right axillary lymph node (ALN) and injection site of living mice. Fluorescent signals were also observed at these locations in a biodistribution study. In addition, fluorescence was detected in frozen ALN sections microscopically. The percentages of doses injected per gram of tissue of axillary and brachial lymph nodes near footpad treated with (68)Ga-NOTA-RITC-SiO(2) nanoparticles were 308.3 +/- 3.4 and 41.5 +/- 6.1, respectively. Little (68)Ga radioactivity was found in other organs.
  
  
  CONCLUSIONS
  Our data provide strong evidence that functionalized silica nanoparticles has a promising potential as organic lymphatic tracer in biomedical imaging such as pre- and intraoperative surgical guidance.
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul, South Korea.
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Jeon
authors.forename: Young-Hwa
authors.initials: YH
authors.lastname: Kim
authors.forename: Kihwan
authors.initials: K
authors.lastname: Choi
authors.forename: Jing Yu
authors.initials: JY
authors.lastname: Piao
authors.forename: Bo
authors.initials: B
authors.lastname: Quan
authors.forename: Yun-Sang
authors.initials: YS
authors.lastname: Lee
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Jeong
authors.forename: June-Key
authors.initials: JK
authors.lastname: Chung
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
authors.forename: Jaetae
authors.initials: J
authors.lastname: Lee
authors.forename: Doo Soo
authors.initials: DS
authors.lastname: Chung
authors.forename: Keon Wook
authors.initials: KW
authors.lastname: Kang
mesh_terms: D000818:Animals; D005121:Extremities; D005260:Female; D005629:Frozen Sections; D005708:Gallium / Q000493:pharmacokinetics / Q000494:pharmacology; D006571:Heterocyclic Compounds / Q000493:pharmacokinetics / Q000494:pharmacology; D006573:Heterocyclic Compounds, 1-Ring; D008198:Lymph Nodes / Q000033:anatomy & histology* / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012235:Rhodamines / Q000493:pharmacokinetics; D012822:Silicon Dioxide / Q000493:pharmacokinetics / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D014018:Tissue Distribution / Q000187:drug effects
chemical_list: D006571:Heterocyclic Compounds; D006573:Heterocyclic Compounds, 1-Ring; D012235:Rhodamines; C048993:1,4,7-triazacyclononane-N,N',N''-triacetic acid; D012822:Silicon Dioxide; C027755:rhodamine isothiocyanate; D005708:Gallium