Dextran-coated superparamagnetic amorphous Fe–Co nanoalloy for magnetic resonance imaging applications

•Amorphous Fe–Co nanoalloy was prepared via wet chemical reduction approach.•The Fe–Co nanoalloy is water-soluble, stable, and biocompatible.•The Fe–Co nanoalloy is superparamagnetic.•The Fe–Co nanoalloy exhibits T2-weighted MR enhancement both in vitro and in vivo.

For magnetic resonance imaging applications, a facile approach for water-soluble dextran coated amorphous Fe–Co nanoalloy was developed. The as-synthesized nanoalloy had a diameter of 9 nm with a narrow size distribution and showed superparamagnetic property with a saturated magnetization (Ms) of 25 emu/g. In vitro cytotoxicity test revealed that it was biocompatible at a concentration below 120 μg/mL. It can be uptaken by HeLa cells effectively and resulted in the obvious T2 effect after internalization. Biodistribution studies in conjunction with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) confirmed that Fe–Co nanoalloy was preferentially accumulated in lung and spleen after intravenous injection for 4 h. In vivo MRI, dextran-coated Fe–Co nanoalloy can serve as a sensitive contrast agent for MR imaging, especially in the spleen, so we believe that it maybe hold great promise for diagnosis of splenic disease by appropriately functionalizing their surface.

Graphical abstractA dextran-coated Fe–Co nanoalloy was developed serving as a sensitive contrast agent for magnetic resonance imaging applications.Figure optionsDownload full-size imageDownload as PowerPoint slide