The Research On Mri Of Contrast Agent Nanoparticles C225-USPIO Marker Targeting To The Nasopharyngeal Carcinoma Xenograft In Nude Mice

Objective Prepare the contrast agent nanoparticles C225-USPIO targeting to the epidermal growth factor receptor, and observe the value of MRI of nasopharyngeal carcinoma xenograft in nude mice marked by this agent.Methods Combining C225(Cetuximab) with USPIO through EDC, which aimed at targeted contrast agent nanoparticles(C225-USPIO), and the diameter of the agent was measured by Granulometer and Atomic Force Microscope(AFM); The EGFR high-expression of nasopharyngeal carcinoma SUNE1 lines were transplanted into the thigh ventral subcutaneous in the right hind leg of 12 female nude mice, When the diameters of transplanted tumor grow up to 5 mm, divide them randomly into two groups. Six for experimental group(C225-USPIO), the other for control group(USPIO). C225-USPIO(1000μmol Fe/kg) and USPIO(1000μmol Fe/kg) were separately injected into nude mice through caudal vein, and respectively scanned by 4.7T/30 cm small animals MR T2WI Imaging after 0, 8, 24 and 72 hour, which aimed at analyzing the signal strength of different time points and the existence of contrast agent nanoparticles in the tumor tissues which were detected by Prussian Blue Staining.Results PSA and AFM showed that the diameters of C225-USPIO were about 45-50 nm. MRI showed that after injecting C225-USPIO in the experimental group, T2 value of xenograft at 8h decreased slightly comparing with the value at 0 h(P> 0.05). T2 value decreased significantly in 24 h(P< 0.05); However, there was no significant change in 72 h(P> 0.05). While in the control group, the T2 values were no significant changes at each time point during 8 h-72 h compared with the value at 0 h(P> 0.05). Moreover, the Prussian Blue Staining analysis found no significant iron particles in the tumor tissue after 72 h.Conclusion C225-USPIO particles could get through capillary, which can be used in magnetic resonance immunization imaging in vivo, and can reduce MRI T2 signal intensity of xenograft in nude mice. The study indicated that C225-USPIO have a certain specificity and targeting property.