Synthesis of redox-active Ce$_{0.75}$Bi$_{0.15}$Tb$_{0.1}$F$_3$ nanoparticles and their biocompatibility study in vitro

Cerium fluoride (CeF$_3$) nanoparticles (NPs), being a unique nanozyme and redox-active nanomaterial, show high promise for advanced biomedical applications. Doping of CeF$_3$ NPs with the other chemical elements allow one to increase their catalytic activity, impart them new functional properties, and also to increase the efficiency of their interaction with ionizing radiation, which is important in the development of novel nanoradiosensitizers. In this article, we synthesized citrate-stabilized Ce$_{0.75}$Bi$_{0.15}$Tb$_{0.1}$F$_3$ nanoparticles, which demonstrate high colloidal stability, have good luminescent properties and radiation-induced redox activity. Cytotoxicity analysis of Ce$_{0.75}$Bi$_{0.15}$Tb$_{0.1}$F$_3$ NPs using normal and tumor cells in vitro showed the sensitivity of B16/F10 and EMTP6 tumor cell lines to the nanoparticles at high concentrations (0.5 – 1 mM). Obtained experimental results allow us to consider Ce$_{0.75}$Bi$_{0.15}$Tb$_{0.1}$F$_3$ nanoparticles as a possible platform for the development of a new class of nanoradiosensitizers for radiation therapy purposes.