OBJECTIVETo evaluate the targeted distribution of cis-platin magnetic nanoparticles (CDDP-MNP) in normal mice.

METHODSThirty-two normal mice were randomly assigned into 4 equal groups. External magnetic field of 4100-4200 Gs was established in the unilateral kidney area of each mouse, and CDDP-MNP was administered via the tail vein, with the external magnetic field maintained in groups A, B, C, and D for 30 min and 1, 2 and 4 h after the injection, respectively. A flame atomic absorption spectrometer (AAS) was used to detect CDDP concentration in the mouse kidney tissues. Magnetic resonance imaging (MRI), Prussian blue staining, and transmission electron microscopy (TEM) were used to detect the distribution of the magnetic nanoparticles in vivo.

RESULTSIn groups A, B and C, the concentrations of CDDP in the targeted kidney tissues increased significantly in comparison with those in non-targeted kidney. The signal intensity of the targeted kidney tissue was lower than that of the non-targeted kidney on T2-weighted MR images. TEM and Prussian blue staining demonstrated MNP distribution in the lumens and endothelial cells of the blood capillary in the kidney tissue.

CONCLUSIONCDDP-MNP allows targeted distribution induced by external magnetic field in normal mice after intravenous injection.