^99mTc（K（HYNIC）₂-3G-RGD₂）（Tricine） For Imaging The Nude Mice Bearing Lung Cancer

ObjectiveTosynthesize99mTc{lysine(6-hydrazinonicotinyl)2-Gly3-E[Gly3-c(RGDfK)]2}(tricine)99m Tc(K(HYNIC)2-3G-RGD2)(tricine) and evaluate its bio-distribution in vivo and vitro in Balb/c nude mice bearing human lung cancer xenograft.Methods99mTc(K(HYNIC)2-3G-RGD2)tricine)kit (PH=6.8)(20μg) was dissolved to0.4ml deionized water, adding sequentially20μl SnCl2(1μg/μl)as regent and about74MBq99mmTc04-(<1ml), after15minutes water bath99mTc(K(HYNIC)2-3G-RGD2)(tricine) was synthetized. The labeling yield and radiochemical purity of99mTc(K(HYNIC)2-3G-RGD2)(tricine)were analyzed with HPLC. Fifteen Balb/c mice were randomly divided into five groups, each was injected with99mTc(K(HYNIC)2-3G-RGD2)(tricine)(0.1ml,3.7MBq)via tail vein, and the bio-distribution in dissected organs were measured at0.5h,1h,2h,4h and8h respectively after the injection. Fifteen nude mice bearing A549lung cancer xenografts were randomly divided into5groups at0.5h、1h、2h、4h、8h time points, then the imaging was acquired with micro SPECT/CT in vivo. The xenografts ex vivo were prepared into pathological slide.Results The radio labeling yield was (97±1.5)%and the radiochemical purity was over95%. The bio-distribution in normal mice showed rapid clearance from blood (the uptake was(4.27±0.36)%ID/g at1h postinjection).99mTc(K(HYNIC)2-3G-RGD2)(tricine)was excreted mainly via the kidney with medium accumulation in the liver and spleen, the intestine was little more(the uptake of liver, stomach, intestine was (12.85±1.12),(3.49±0.26),(14.26±0.11)%ID/gat1h postinjection). Obvious uptake of radioactivity was found in tumor tissue of the Balb/c nude mice bearing human lung cancer with maximum T/NT ratio of22.31±0.39at1h postinjection. The xenografts ex vivo pathological slidevalidated vascular endothelial express integrinανβ3.Conclusions99mTc(K(HYNIC)2-3G-RGD2)(tricine)can be easily prepared with high radiolabeling yield and radiochemical purity. The good bio-distribution and good targeting characteristics make it a hopeful candidate for the diagnosis of human lung cancer overexpress the integrin ανβ3receptor.