Magnetic Isolation of Cancer-derived Exosomes Using Fe/Au Magnetic Nanowires

Isolating tumor exosomes (TEX) secreted by cancer cells can provide valuable information about the state of a tumor. Here, we present a method to rapidly isolate TEX using magnetic nanowires (MNWs). Specifically, two sets of Fe/Au segmented MNWs were used to isolate TEX released by canine osteosarcoma cell lines (OSCA 8, 32, and 40). These MNWs were prepared by electrodeposition showcasing similar length (2.2(1) μm) and diameter (36(3) nm), but different Fe/Au segment thickness: 120(20)/30(6) nm (sample A) and 28(7)/3(1) nm (sample B). Magnetic measurements indicate that we can effectively tune the magnetic response of the MNWs by changing their segment thickness, obtaining a more anisotropic behavior for sample A. The internalization of these MNWs by OSCA cells as a function of their concentration has been followed by fluorescence microscopy, and a concentration around 25 µg of Fe/Au MNWs per 3×105 cells has been defined as optimal. Electron microscopy images have revealed that, once internalized, these ...