^99mTc-MDP as an imaging tool to evaluate the in vivo biodistribution of solid lipid nanoparticles

The aim of this study was to establish the in vivo uptake and tissue distribution of ^99mTc-MDP-encapsulated Solid Lipid Nanoparticles (SLNs) post administration. Radioactive ^99mTc-MDP encapsulated into SLNs was administered to rats to trace their biodistribution through imaging and ex vivo studies. As expected IV injected ^99mTc-MDP exhibited predominant visual bone uptake and a high localisation of particles in the kidneys (3.87%ID/g) followed by bone (2.66%ID/g). IV administered ^99mTc-MDP encapsulated by SLN showed similar uptake than ^99mTc-MDP. Orally administrated ^99mTc-MDP showed no uptake in any organs except the GI-tract while orally administered ^99mTc-MDP-SLN showed distinct transfer of ^99mTc-MDP from the GI tract with measurable levels in the kidneys and bone.