99mTc/188Re-labelled lipid nanocapsules as promising radiotracers for imaging and therapy: formulation and biodistribution.
OBJECTIVE
This study focuses on a promising carrier system for imaging and therapeutic purposes using lipid nanocapsules. To assess their potential for clinical use, we labelled nanocapsules with (99m)Tc and (188)Re and analysed some kinetic biodistribution parameters after intravenous injection in rats.


METHODS
Lipophilic complexes [(99m)Tc/(188)Re(S(3)CPh)(2)(S(2)CPh)] ((99m)Tc/(188)Re-SSS) were encapsulated within the nanoparticles during their manufacture with quantitative yield and satisfactory radiochemical purity. Rats were injected intravenously with 3.7 MBq (99m)Tc/(188)Re-labelled nanocapsules and sacrificed at 5, 15 and 30 min and 1, 2, 4, 8, 12, 16, 20 and 24 h.


RESULTS
Dynamic scintigraphic acquisitions showed predominant hepatic uptake, and ex vivo counting indicated a long circulation time of labelled nanocapsules, with a half-life of 21+/-1 min for (99m)Tc and 22+/-2 min for (188)Re. Very weak urinary elimination was observed, indicating good stability of (99m)Tc and (188)Re labelling.


CONCLUSIONS
(99m)Tc/(188)Re-SSS nanocapsules can be obtained with high yield and satisfactory radiochemical purity. The biodistributions of (99m)Tc/(188)Re-labelled nanocapsules are close to those of classical PEG-coated particles and show good stability of (188)Re/(99m)Tc-SSS labelling.
Ballot
Sandrine
S
Ecole Nationale Supérieure de Chimie de Rennes UMR CNRS 6052 'Synthèses et Activations de Biomolécules', Institut de Chimie de Rennes, Avenue du Général Leclerc, 35700, Rennes-Beaulieu, France.
Noiret
Nicolas
N
Hindré
François
F
Denizot
Benoît
B
Garin
Etienne
E
Rajerison
Holisoa
H
Benoit
Jean-Pierre
JP
D000818:Animals; D004337:Drug Carriers / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods; D008055:Lipids / Q000737:chemistry*; D008297:Male; D008657:Metabolic Clearance Rate; D043942:Nanotubes / Q000737:chemistry*; D009928:Organ Specificity; D011868:Radioisotopes / Q000737:chemistry / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D012211:Rhenium / Q000737:chemistry / Q000493:pharmacokinetics* / Q000627:therapeutic use; D013667:Technetium / Q000737:chemistry / Q000493:pharmacokinetics* / Q000627:therapeutic use; D014018:Tissue Distribution
D004337:Drug Carriers; D008055:Lipids; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D012211:Rhenium; D013667:Technetium