Magnetic resonance and light microscopy investigation of a dextran coated magnetic fluid

A dextran-coated magnetite-based magnetic fluid (MF) sample (DexMF) was developed for cancer diagnostic and therapeutic purposes. In order to perform biological studies DexMF samples were endovenously injected into female Swiss mice. Magnetic resonance (MR) spectra showed a broad line around $\text{g=2,}$ typical of magnetic nanoparticles (MNPs) suspended in a nonmagnetic matrix. The MR data showed that MNPs essentially spread in liver, spleen, and bone marrow. MNPs in blood stream were found up to 60 min after injection. Histological analysis also showed MNP agglomeration in liver, spleen, and bone marrow, from 1 h up to 28 days. No damaged cells or any other kind of alteration were observed in the investigated tissues. The data suggested that DexMF sample is biocompatible and adequate for biomedical applications.