Acta Biomaterialia publication: In vivo biodistribution of calcium phosphate nanoparticles after intravascular, intramuscular, intratumoral, and soft tissue administration in mice investigated by small animal PET/CT

In this paper by Kollenda et al., the MOLECUBES β-CUBE and X-CUBE were used to compare the biodistribution of 68Ga-labelled nanoparticles following different application routes: intravenous, intramuscular, intratumoral, and into soft tissue.

Acta Biomaterialia. 2020; 109:244-253. doi: 10.1016/j.actbio.2020.03.031.

Abstract

Calcium phosphate nanoparticles were covalently surface-functionalized with the ligand DOTA and loaded with the radioisotope 68Ga. The biodistribution of such 68Ga-labelled nanoparticles was followed in vivo in mice by positron emission tomography in combination with computer tomography (PET-CT). The biodistribution of 68Ga-labelled nanoparticles was compared for different application routes: intravenous, intramuscular, intratumoral, and into soft tissue. The particle distribution was measured in vivo by PET-CT after 5 min, 15 min, 30 min, 1 h, 2 h, and 4 h, and ex vivo after 5 h. After intravenous injection (tail vein), the nanoparticles rapidly entered the lungs with later redistribution into liver and spleen. The nanoparticles remained mostly at the injection site following intramuscular, intratumoral, or soft tissue application, with less than 10 percent being mobilized into the blood stream.