Self-assembled terbium-amino acid nanoparticles as a model for terbium biosafety and bone repair ability assessment

Terbium (Tb) has been widely applied in biomedical field due to its excellent physicochemical properties , and is mainly deposited in bone tissue. However, its effects on bone and long-term biosafety have not been investigated in detail yet. In this study, self-assembled terbium-cysteine nanoparticles (Tb-Cys NPs) are designed as a model for the biosafety and bone repair ability assessment of Tb, which eliminates the disturbance of other factors as much as possible. Through metabolism, Tb is excreted gradually without obvious damage to major organs. Interestingly, Tb-Cys NPs efficiently promote bone repair . This study confirms the preferable biocompatibility and bone repair property of Tb and provides a competent reference for Tb biosafety during clinical applications. Further, the form of metal-amino acid assembly can serve as a kind of suitable model for the reasonable assessment of the long-term biosafety and the functions on tissues of other rare earth elements.