Lipophilic phosphonium–lanthanide compounds with magnetic, luminescent, and tumor targeting properties

Multifunctional phosphonium–lanthanide compounds that simultaneously possess paramagnetism, luminescence, and tumor mitochondrial targeting properties were prepared by use of a facile method. These compounds were fully characterized by use of 1H, 13C, 31P NMR, FT-IR, and elemental analyses. The thermal properties of these compounds including melting points and decomposition temperatures were investigated using DSC and TGA analyses. In addition, the paramagnetism, luminescence, and tumor targeting properties of these multifunctional compounds were confirmed by respective use of SQUID, fluorescence, and cell cytotoxicity studies. All compounds exhibited paramagnetism at room temperature, which could provide target delivery of these compounds to parts of the body containing tumor cells using a strong external magnetic field. In addition, these compounds display two major characteristic emissions originating from Dy3 +, which can be utilized for imaging tumor cells. The IC50 values of these compounds measured against normal breast cell line (Hs578Bst) are significantly greater than those measured against the corresponding carcinoma breast cell line (Hs578T), clearly indicating the selective tumor targeting properties of these compounds. Confocal fluorescence microscopy studies were used to confirm the yellowish-green fluorescence corresponding to the emission of dysprosium thiocyanate anion within cancer cells upon exposure of cancer cell lines such as human pancreatic carcinoma cell line (MIAPaCa-2) and human breast carcinoma (MDA-MB-231) to a solution of these phosphonium–dysprosium compounds.

Magnetic, luminescent and tumor targeting phosphonium–dysprosium compounds were conveniently synthesized and investigated for potential applications as selective tumor therapeutic and imaging agents.Figure optionsDownload as PowerPoint slideHighlights
► Paramagnetic, luminescent, and tumor-targeting phosphonium-lanthanides prepared.
► Strong response to magnetic field and fluorescent emission observed.
► Selective cytotoxicities againts carcinoma cell lines demonstrated.
► Confocal fluorescent imaging of tumor cells achieved.