Synthesis of magnetic nanobiomaterials and its biological effects.

Iron oxides and its hydrate nanoparticles, for example, nanoFe3O4 and nanoFe3O4 with hydroxyl, were synthesized by hydrothermal method, their sizes and features are evaluated by infrared spectra and Scanning Electron Microscope (SEM) etc. The dimensions of these nanoparticles produced are about 50-120 nm. In the investigation of influence of nanoFe3O4 and nanoFe3O4 with hydroxyl on crystalline states of amino acid molecules, their crystalline forms are different to that of pure amino acid molecules. The positions and widths of peaks of these nanoparticles in the infrared spectra of absorption are changed largely relative to that of pure amino acid molecules. From the experiments of microscope observation and infrared spectra of re-crytalline amino acids we see that the nanoFe3O4 and nanoFe3O4 with hydroxyl can change the structure of amino acid molecules. To study the toxicity of synthesized nanoparticles, the MTT (3-(4,5-dimethyl-thiazol 2-yl)-2,5 diphenyltetrazolium bromide) assay was used. The OD value (Optical Density) was used to calculated RGR (Relative Generation Rate) of cells, which determined the grade of cytotoxicity. The RGR of nanoparticles of iron oxide and its hydrate are about 1 to 2, which indicate that they have a lower toxicity.