RESUMO
Objective To observe the targeting function of high affinity anti-EGFR monoclonal antibody (Cetuximab)conjugated superparamagnetic iron oxide-dopamine (anti-EGFR-PEG-SPIO) lung cancer cells via epidermal growth factor receptor (EGFR),as well as the feasibility for surveillance of tumor targeting with MRI.Methods Nanoparticles (NPs)of anti-EGFR-PEG-SPIO and PEG-SPIO were prepared,and the morphology of nanoparticles was observed with transmission electron microscope (TEM).The hydrodynamic diameter and R2 values of nanoparticles before and after conjugation with anti-EGFR were performed with dynamic light scattering (DLS) and MRI.MRI was performed in incubation with anti-EGFR-PEG-SPIO and PEG-SPIO after 2 h in vitro.The cellular uptake of anti-EGFR-PEG-SPIO and PEG-SPIO was further evaluated using Prussian blue staining and TEM.Results Anti-EGFR-PEG-SPIO and PEG-SPIO showed signal intensity of H460 cells on T2WI,decreased significantly compared with PEG-SPIO.The rate of signal intensity change was -58.2％,-82.7％,-94.4％ and-98.3％,respectively,at iron concentrations of (0,10,20,40,80 μg/ml) of antiEGFR-PEG-SPIO.Prussian blue staining and TEM showed that a lot of intracellular irons of anti-EGFR-PEG-SPIO were observed in H460 cells,but few of PEG-SPIO.Conclusion The effect of active targeting via anti-EGFR in EGFR overexpressed cells can be achieved with anti-EGFR-PEG-SPIO in H460 cells in vitro,and the targeting delivery process could be monitored with 3.0T MRI.