New starch-based radiotracer for lung perfusion scintigraphy.
OBJECTIVE
In order to avoid the microbiological risks linked to human serum albumin macroaggregates (MAA) used for lung perfusion scintigraphy, we developed a new starch-based Tc-99m potential radiopharmaceutical.


METHODS
Microparticles were prepared from oxidised starch coupled to natural polyamine for Tc-99m complexation. Suspensions were formulated as ready-to-use kits for easy one-step labelling procedures.


RESULTS
Particle-size analysis, electron microscopy, and confocal microscopy were performed for microparticle characterisation, and gave a typical size distribution ranging from 7 to 63 microm, with a homogenous population of spherical or oval-shaped microparticles. Radiochemical purity exceeded 95%, and was stable for at least 8 h. When challenged with histidine and human plasma, labelling was also stable. Dynamic scintigraphic acquisitions and biodistribution studies conducted on healthy Wistar rats showed a tracer accumulation with more than 80% of the ID in the lungs after 15 min.


CONCLUSIONS
With clinically significant characteristics such as a lung half-life of 3 h, a lung-to-vascular ratio of 900, and a lung-to-liver ratio of 90, starch-based microparticles exhibit all the qualities for an effective new lung perfusion agent.
Lacoeuille
Franck
F
Inserm U646, University of Angers, 10 rue A. Boquel, 49100 Angers, France. franck.lacoeuille@univ-angers.fr
Hindré
François
F
Denizot
Benoit
B
Bouchet
Francis
F
Legras
Pierre
P
Couturier
Olivier
O
Askiénazy
Serge
S
Benoit
Jean Pierre
JP
Le Jeune
Jean Jacques
JJ
D000818:Animals; D004337:Drug Carriers / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008297:Male; D010316:Particle Size; D010363:Pattern Recognition, Automated / Q000379:methods*; D055420:Perfusion Imaging / Q000379:methods; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013213:Starch / Q000737:chemistry*; D013667:Technetium / Q000737:chemistry / Q000493:pharmacokinetics*
D004337:Drug Carriers; D019275:Radiopharmaceuticals; D013667:Technetium; D013213:Starch