Scintigraphic evaluation of the pharmacokinetics of a soluble polymeric drug carrier.
There is a growing interest in the use of macro-molecular carriers for therapeutic agents. If these carriers can be labelled with an appropriate gamma-emitter, their biodistribution could be followed by scintigraphy. We have imaged the biodistribution of a synthetic branched polypeptide, based on a poly-L-lysine backbone (average molecular mass 45 kDa). The polymer was conjugated to diethylene triamine penta-acetic acid and labelled by chelation with indium-111. Mice were injected i.v. with labelled material and imaged with a gamma-camera with a pin-hole collimator. Images showed the majority of tracer remaining in the blood pool, but about 35% appeared in the urinary bladder within 1.5 h. When the 111In-polymer was fractionated by gel filtration chromatography on S-300, the imaging showed that the early eluting material was retained, the intermediate showed some renal clearance, and the late was rapidly excreted. These findings show the value of gamma-scintigraphy for biodistribution studies with such polymeric drug carriers and its potential for clinical pharmacokinetic studies.
Pimm
M V
MV
Cancer Research Campaign Laboratories, University of Nottingham, UK.
Perkins
A C
AC
Hudecz
F
F
D000818:Animals; D004337:Drug Carriers; D007205:Indium Radioisotopes; D051379:Mice; D008807:Mice, Inbred BALB C; D004369:Pentetic Acid; D011108:Polymers; D014018:Tissue Distribution
D004337:Drug Carriers; D007205:Indium Radioisotopes; D011108:Polymers; D004369:Pentetic Acid