Ligand free FeSn alloy nanoparticles for safe -weighted MR imaging of lung tumors.

Biosafety is a critical issue for the successful translocation of nanomaterial-based therapeutic/diagnostic agents from bench to bedside. For instance, after the withdrawal of clinically approved magnetic resonance (MR) imaging contrast agents (CAs) due to their biosafety issues, there is a massive demand for alternative, efficient, and biocompatible MR contrast agents for future MRI clinical applications. To this end, here we successfully demonstrate the MR contrast abilities and biocompatibilities of ligand-free FeSn alloy NPs for tracking lung tumors. and results reveal the FeSn alloy NPs acting as appreciable weighted MR contrast agents to locate tumors. The construction of iron (Fe) on biocompatible tin (Sn) greatly facilitates the reduction of the intrinsic toxicities of Fe resulting in no significant abnormalities in liver and kidney functions. Therefore, we envision that constructing ligand-free alloy NPs will be a promising candidate for tracking tumors in future clinical applications.