سنتز نانوذرات مغناطيسي عامل‌دار شده با آپتامر EpCAM و بررسي توانايي آن‌ها در جداسازي سلول‌هاي سرطاني در گردش خون (CTC)

Synthesis of Magnetic Nanoparticles Functionalized with EpCAM Aptamer and eva‎luation of Their Ability to Capture Circulating Tumor Cells (CTCs)

زيست فناوري

The early detection of cancer is crucial for reducing the cancer associated mortality. One of the novel methods for early detection of cancer is identification of circulating tumor cells (CTCs), which detach from primary tumors or metastatic sites and enter the peripheral blood. These cells can be detected using epithelial markers such as epithelial cell adhesion molecules (EpCAM). This approach also offers a minimally invasive liquid biopsy technique that reduces the side effects and healthcare costs. The only FDA-approved commercial product based on this method is CELLSEARCH®, which uses immunomagnetic separation of CTCs by the antibodies. In this study, the ability of an anti-EpCAM DNA aptamer conjugated with iron oxide nanoparticles was eva‎luated for the immune-magnetic identification and separation of the cancer cells. For this purpose, iron oxide nanoparticles were first synthesized using a solvothermal method and conjugated to EpCAM aptamers via the glutaraldehyde linkers after coating with silica. The nanoparticles were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), zeta potential analysis, and vibrating-sample magnetometer (VSM). The in vitro cellular assays were then performed using MDA-MB-231 and MCF-7 cell lines to eva‎luate the biocompatibility of nanoparticle via the MTT assay and also to determine the optimal condition for cancer cell detection and separation, including incubation time, nanoparticle concentration, and efficiency of separation. Based on the characterization results, the used method led to the synthesis of crystalline, monodisperse and uniform iron oxide nanoparticles with the sizes of 22 to 30 nm. The cellular studies also showed that the nanoparticles have no toxic effects on the cells, and increasing the incubation time leads to the enhanced efficiency of cancer cell capture. The optimal incubation time was 2 hours. Furthermore, the cell studies showed that the efficiency and sensitivity of present method are different for two cell lines studied. The best results achieved for the MDA-MB-231 cell line, such that more than 81% capture efficiency was obtained in low-density samples (10 cells).

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