The Experimental Study Of^99mTc-NT21MP In Imaging Of Breast Cancer Mouse

Objective：To explore the method of direct radio-labeling of chemokine receptor4(CXCR4) inhibitor derived from virus macro-phage inflammatory protein(NT21MP)by99mTc with relatively high radiochemical purity and stability, screening the bestlabeling conditions, to establish a simple and reliable method of preparation of99mTc-NT21MP;Explore the possibility and feasibility of99mTc-NT21MP targetingdiagnosis of malignancy, providing theoretical and experimental basis for the study oftumor CXCR4receptor imaging. Detect the value of99mTc-NT21MP as breast-positiveSPECT imaging agent.Methods:①NT21MP was directly radio-labeled by99mTc using pretinning method,the selection of a higher rate and tag marking methods radiochemical purity；99mTc-NT21MP were placed in saline at room temperature and normal human serumat37℃, the paper chromatography measured at different time and calculate the rate oflabeled product and the radiochemical purity of labeled, in vivo observation of itsstability, and comparative analysis of selected optimal condition;②To establish thetumor models of breast cancer．SPECT imaging of model mice were detected byintravenous injection99mTc-NT21MP．T/NT value was calculated at0.5h,1h, and2hafter injection of the radiotracer．③Two days after imaging, tail vein injection of the99mTc-NT21MP at2h later and killed tumor-bearing mice. blood and major organswere determined and calculated per gram Organization percentage radiation doserate(%ID/g)．Results:①The radiochemical purity of99mTc-NT21MP was95%. It was stable inblood plasma within2hours; its radiochemical purity was nearly90%.②It makestumor area imaged on SPECT when99mTc-NT21MP was injected in tumor-bearingmice and T/NT reaches6.0in2hours.③99mTc-NT21MP could target to tumor tissuesafter injecting. T/NT reached2.4in2hours.Conclusions:①99mTc-NT21MP is simple, rapid, radiochemical purity productobtained higher marks, better stability, no further purification;②it makes clearly and quality pictures when99mTc-NT21MP inject into tumor-bearing mice.③99mTc-NT21MP has a high value in the diagnosis of CXCR4positive tumors, and itmay become a new molecular probe for the diagnosis and therapy of breast cancer.