Synthesis and Application Evaluation of the Novel Nanocluster MnS@Tf for Tumor Management

<b>Background:</b> Exploring new management and treatment strategies for inoperable colorectal cancer is key to improving patient prognosis. Nanotechnology combining medical imaging with cancer treatment provides a new solution for the management of advanced cancer. <b>Methods:</b> This study designed and synthesized the dual-modal molecular imaging probe MnS@Tf-¹²⁵I and evaluated its diagnostic and therapeutic applications in colorectal cancer with high expression of transferrin receptors (TfR) through in vitro and in vivo studies. <b>Results</b>: The MnS@Tf synthesized in this study can release manganese ions for chemodynamic therapy (CDT) and magnetic resonance imaging (MRI) and can be combined with hydrogen sulfide (H₂S) for gas therapy in response to the acidic tumor microenvironment. The molecular imaging probe MnS@Tf-¹²⁵I was labeled with ¹²⁵I to verify MnS@Tf's targeting and high affinity for tumors with high expression of TfR through in vitro experiments. In vitro cell experiments demonstrated the killing effect of MnS@Tf on CT26 cells. The results of blood clearance and imaging after intravenous injection of MnS@Tf-¹²⁵I showed that MnS@Tf could stably exert targeted tumor-killing effects in mice over an extended period. In vivo experiments indicated that MnS@Tf not only effectively initiated T1-weighted MRI but also significantly inhibited tumor growth in CT26-bearing mouse models. <b>Conclusions</b>: The dual-modal molecular imaging probe MnS@Tf synthesized in this study can specifically target tumors with high expression of TfR and has good therapeutic effects both in vitro and in vivo, indicating that the nanocluster has broad application prospects in clinical tumor management.