Open AccessAssessment of the biodistribution of an [ 18 F]FDG‐loaded perfluorocarbon double emulsion using dynamic micro‐PET in rats
Author(s) -
Fabiilli Mario L.,
Piert Morand R.,
Koeppe Robert A.,
Sherman Phillip S.,
Quesada Carole A.,
Kripfgans Oliver D.
Publication year - 2013
Publication title -
contrast media & molecular imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.714
H-Index - 50
eISSN - 1555-4317
pISSN - 1555-4309
DOI - 10.1002/cmmi.1532
Subject(s) - biodistribution , emulsion , nuclear medicine , chemistry , pharmacokinetics , positron emission tomography , standardized uptake value , medicine , pharmacology , in vitro , biochemistry
Perfluorocarbon (PFC) double emulsions loaded with a water‐soluble, therapeutic agent can be triggered by ultrasound in a process known as acoustic droplet vaporization. Elucidating the stability and biodistribution of these sonosensitive vehicles and encapsulated agents is critical in developing targeted drug delivery strategies using ultrasound. [ 18 F]fluorodeoxyglucose (FDG) was encapsulated in a PFC double emulsion and the in vitro diffusion of FDG was assessed using a Franz diffusion cell. Using dynamic micro‐positron emission tomography and direct tissue sampling, the biodistribution of FDG administered as a solution (i.e. non‐emulsified) or as an emulsion was studied in Fisher 344 rats ( n = 6) bearing subcutaneous 9L gliosarcoma. Standardized uptake values (SUVs) and area under the curve of the SUV (AUC SUV ) of FDG were calculated for various tissues. The FDG flux from the emulsion decreased by up to a factor of 6.9 compared with the FDG solution. FDG uptake, calculated from the AUC SUV , decreased by 36% and 44% for brain and tumor, respectively, when comparing FDG solution vs FDG emulsion ( p < 0.01). Decreases in AUC SUV in highly metabolic tissues such as brain and tumor demonstrated retention of FDG within the double emulsion. No statistically significant differences in lung AUC SUV were observed, suggesting minimal accumulation of the emulsion in the pulmonary capillary bed. The liver AUC SUV increased by 356% for the FDG emulsion, thus indicating significant hepatic retention of the emulsion. Copyright © 2013 John Wiley & Sons, Ltd.