Colloidal magnetic nanocrystals have been studied extensively on account of their peculiar magnetic properties resulting from their nanosized domains. They are core materials in many applications related to data storage, magnetic separation, drug delivery, and magnetic resonance image (MRI) contrast enhancement.
Magnetic ferrites, which are expressed by MFe2O4 (M: Fe, Co, Mn, Ni, Cu, Zn), have attracted considerable attention and been well studied because of their easy magnetic property engineering by adjusting the M2+ ion. Various methods have been used to synthesize ferrite nanocrystals, including reverse micelle and nonhydrolytic methods. We report a new method for fabricating MnFe2O4 nanocrystals and their toxicity studies.
Additionally, the possibilities for a dual functional MRI contrast agent in T1 and T2 imaging will be presented. A magnetization value of a sample is much lower than those reported previously, which might be due to the small size and low crystallinity of the ferrite nanoparticles. Although the weak magnetic properties could be regarded as a drawback, it was found that it can provide an opportunity for dual MRI contrast agents. Generally, manganese ferrite has a T2 weighted effect because of its strong magnetic properties. However, the low r2 value of ferrite by this method gives it a useful T1 weighted effect.
The cytotoxicity of manganese ferrite was examined on MCF-10A normal cells and various breast cancer cells (MDA-MB435S, MDA-MB 231, and MCF-7). Few reports have been published on cytotoxicity of manganese ferrite nanocrystals. The microscopy images showing the morphological changes indicated that two type cells were not damaged at concentrations between 0.1 mM and 1 mM. The method could be applied to other ferrite nanoparticles including cobalt ferrite.