Comparative toxicity and contrast enhancing assessments of GdO@BSA and MnO@BSA nanoparticles for MR imaging of brain glioma.

The albumin-templated GdO and MnO nanoparticles (NPs) have been developed as a new type of magnetic resonance (MR) T contrast agents. However, their potential toxicity and applicability for MR imaging of brain gliomas has not been fully explored so far. In this study, we prepared GdO@BSA and MnO@BSA nanoparticles (NPs) and investigated their toxicity comprehensively and comparatively by H&E staining, blood biochemical analysis, and adverse outcome pathways testing. It is revealed that both GdO@BSA and MnO@BSA NPs are biocompatible at a rational dose level. Although the relaxivity of MnO@BSA NPs is less than that of GdO@BSA NPs, the MnO@BSA NPs lead to a greater contrast enhancement in the brain glioma due to the controlled release of Mn ions under the acidic tumor microenvironmental conditions. These comparative toxicity and contrast enhancement data are of fundamental importance for the clinical translation of GdO@BSA and MnO@BSA NPs as MR contrast agents for brain glioma diagnosis.