In vivo imaging of sentinel nodes using fluorescent silica nanoparticles in living mice.
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.
Jeon
Yong Hyun
YH
Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul, South Korea.
Kim
Young-Hwa
YH
Choi
Kihwan
K
Piao
Jing Yu
JY
Quan
Bo
B
Lee
Yun-Sang
YS
Jeong
Jae Min
JM
Chung
June-Key
JK
Lee
Dong Soo
DS
Lee
Myung Chul
MC
Lee
Jaetae
J
Chung
Doo Soo
DS
Kang
Keon Wook
KW
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
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