Fe3O4-Cy5.5-trastuzumab magnetic nanoparticles for magnetic resonance/near-infrared imaging targeting HER2 in breast cancer

Abstract This study developed a probe Fe 3 O 4 -Cy5.5-trastuzumab with fluorescence and magnetic resonance imaging functions that can target breast cancer with high HER2 expression, aiming to provide a new theoretical method for the diagnosis of early breast cancer. Fe 3 O 4 -Cy5.5-trastuzumab nanoparticles were combined with Fe 3 O 4 for T 2 imaging and Cy5.5 for near-infrared imaging, and coupled with trastuzumab for HER2 targeting. We characterized the nanoparticles used transmission electron microscopy, hydration particle size, Zeta potential, UV and Fourier transform infrared spectroscopy, and examined its magnetism, fluorescence, and relaxation rate related properties. CCK-8 and blood biochemistry analysis evaluated the biosafety and stability of the nanoparticles, and validated the targeting ability of Fe 3 O 4 -Cy5.5 trastuzumab nanoparticles through in vitro and in vivo cell and animal experiments. Characterization results showed the successful synthesis of Fe 3 O 4 -Cy5.5-trastuzumab nanoparticles with a diameter of 93.72 ± 6.34 nm. The nanoparticles showed a T 2 relaxation rate 42.29 mM −1 s −1 , magnetic saturation strength of 27.58 emg g −1 . Laser confocal and flow cytometry uptake assay showed that the nanoparticles could effectively target HER2 expressed by breast cancer cells. As indicated by in vitro and in vivo studies, Fe 3 O 4 -Cy5.5-trastuzumab were specifically taken up and effectively aggregated to tumour regions with prominent NIRF/MR imaging properties. CCK-8, blood biochemical analysis and histological results suggested Fe 3 O 4 -Cy5.5-trastuzumab that exhibited low toxicity to major organs and good in vivo biocompatibility. The prepared Fe 3 O 4 -Cy5.5-trastuzumab exhibited excellent targeting, NIRF/MR imaging performance. It is expected to serve as a safe and effective diagnostic method that lays a theoretical basis for the effective diagnosis of early breast cancer. This study successfully prepared a kind of nanoparticles with near-infrared fluorescence imaging and T 2 imaging properties, which is expected to serve as a new theory and strategy for early detection of breast cancer.