MoSe₂-based magnetic nanosystem for clinical enrichment, retrieval and elimination of circulating tumor cells

The detection, analysis and clearing of circulating tumor cells (CTCs) from patients’ bloodstream at an early stage are important to diagnose the primary tumor progression and decrease cancer metastasis-related mortality. Herein, we developed a molybdenum diselenide nanosheet (MoSe₂ NS) based magnetic nanosystem, which was surface functionalized with the anti-epithelial cell adhesion molecule (anti-EpCAM) antibody. CTCs were successfully isolated by the magnetic nanosystem from blood samples of clinical cancer patients. Highly efficient CTCs enrichment was achieved when the nanosystem was applied with a concentration down to 25 µg ml⁻¹ in both static and biomimetic circulating conditions. The nanosystem was demonstrated biocompatible without obvious cytotoxicity, allowing in vitro culture of the captured cells for downstream analysis. Further, the magnetic nanosystem presented a reinforced photothermal effect due to the integration of several photothermal agents including MoSe₂ NS, ferroferric oxide (Fe₃O₄) nanoparticles, and polydopamine (pDA), allowing fast in-situ elimination of the captured cells under NIR laser (808 nm) irradiation. This work represents a multimode system that enables highly efficient enrichment of rare CTCs from patients’ blood for either retrieval or clearing, with great promise for early cancer diagnosis and possible treatment screening.