Preparation and long-term biodistribution studies of a PAMAM dendrimer G5-Gd-BnDOTA conjugate for lymphatic imaging.
OBJECTIVE
To demonstrate the use of gadolinium (Gd)-labeled dendrimers as lymphatic imaging agents and establish the long-term biodistribution (90-day) of this type of agent in mice.


METHODS
A G5-Gd-BnDOTA dendrimer was prepared and injected into mice and monkeys for MR lymphangiography, and long-term biodistribution of the conjugate was studied.


RESULTS
Administration of G5-Gd-BnDOTA in mice demonstrated a rapid uptake in the deep lymphatic system while injection in monkeys showed enhanced internal iliac nodes, indicating its general utility for lymphatic tracking. Biodistribution studies to 90 days showed that gadolinium conjugate is slowly being eliminated from the liver and other organs.


CONCLUSIONS
The use of G5-Gd-BnDOTA holds great promise for lymphatic imaging, but its slow clearance from the body might hamper its eventual clinical translation.
Ana Christina
AC
Opina
2Molecular Imaging Program, National Cancer Institute, MD, USA.
Karen J
KJ
Wong
3Clinical Research Directorate/Clinical Monitoring Research Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, MD, USA.
Gary L
GL
Griffiths
2Molecular Imaging Program, National Cancer Institute, MD, USA.
Baris I
BI
Turkbey
2Molecular Imaging Program, National Cancer Institute, MD, USA.
Marcelino
M
Bernardo
2Molecular Imaging Program, National Cancer Institute, MD, USA.
Takahito
T
Nakajima
2Molecular Imaging Program, National Cancer Institute, MD, USA.
Hisataka
H
Kobayashi
2Molecular Imaging Program, National Cancer Institute, MD, USA.
Peter L
PL
Choyke
Olga
O
Vasalatiy
D000818:Animals; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D003287:Contrast Media; D050091:Dendrimers / Q000737:chemistry* / Q000493:pharmacokinetics*; D005260:Female; D000882:Haplorhini; D008208:Lymphatic System / Q000378:metabolism*; D008220:Lymphography / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D014018:Tissue Distribution
D003287:Contrast Media; D050091:Dendrimers; C104700:PAMAM Starburst
G5–Gd-BnDOTA; MRI contrast agent; PAMAM G5; biodistribution; dendrimers; lymphatic imaging