Objective      To build lymphatic endothelial cells (LECs)-targeted PEG-GoldMag-pod nanoparticles with gold magnetic particles (GoldMag

) modified by polyethylene glycol (PEG) and anti-podoplanin antibody (PodAb).       Methods      PEG was covalently bound to GoldMag to obtain PEG-GoldMag nanoparticles mediated by cetyltrimethyl ammonium bromide (CTAB). PodAb was covalently bound to PEG-GoldMag to construct PEG-GoldMag-pod nanoparticles. The characteristics of the PEG-GoldMag-pod nanoparticles were tested. Human dermal lymphatic endothelial cells (HDLECs) were incubated with breast cancer cells in Millicell cell culture inserts to acquire breast cancer LECs. The breast cancer LECs were co-cultured with PEG-GoldMag-pod nanoparticles at iron concentrations of 5

10

15

30

and 45 μg/mL separately for 24 h. The labeling ratio was evaluated by Prussian blue staining. Magnetic resonance (MR) imaging was performed to the labeled breast cancer LECs to investigate the signal characteristics. HDLECs without induction were used as control.       Results      The water-soluble PEG-GoldMag-pod nanoparticles were obtained successfully. Dose-dependence was observed in the labeling efficiencies and MR images of the labeled cells. The labeling ratio and signal intensity (SI) of breast cancer LECs were significantly higher than those of HDLECs. With increase of iron concentration

SI gradually increased in SE T

1

WI

and decreased in FSE T

2

WI and GRE T*

2

WI. The SI in T*

2

WI was significantly stronger than that in T

2

WI.       Conclusion      The PEG-GoldMag-pod nanoparticles can be used to label breast cancer LECs. MR imaging of the labeled LECs can reflect the expression of podoplanin on LECs.