In vitro investigation of mice blood doped with magnetite-coated nanoparticles

Magnetic nanoparticles offer many attractive possibilities for biomedical applications. These magnetic nanoparticles can be engineered by surface-coating them with special molecules to interact with or bind to a biological structure, thereby providing a controllable means of targeting specific biological sites. The drawback that mostly concerns the wide use of biocompatible magnetic fluids in new technologies is the possible adverse effect of foreign particles in the organism. In particular, the mechanism of interaction between the surface-coated magnetic nanoparticle and the blood components, for instance, is still not clearly elucidated. This study reports on in vitro biological tests with three types of biocompatible magnetic fluids, alkaline treated dextran, carboxymethyldextran and magnetite surface-coated with citrate. These fluids were injected in vitro in samples of mice blood and analyzed, using micro-Raman technique. It is clear from the acquired Raman spectra and from obtained values for oxy/deoxy ratios from blood-doped samples compared to the reference sample values, that the reference samples were less oxygenated than the blood-doped samples. To understand this improvement in the oxy/deoxy ratio for the blood-doped samples, it is interesting to consider the kind of the nanoparticle coat. The citrate molecule has a larger amount of the COO- terminal, compared with carboxymethyidextran and alkaline treated dextran. The presence of the non-bonded COO-terminal on the magnetite nanoparticle surface may satisfy this demand that oxygen status varies on the blood-doped samples. This study showed the use of micro-Raman spectroscopy for monitoring the hemoglobin structural changes, which may be associated with the oxygen binding process or electronic transfer mechanism.