Click chemistry was used to study on radiolabeling of 1,2,3-triazole analogs with fac-[188 Re(CO) 3 (H 2 O) 3]+ . CuSO 4 /L-sodium ascorbate was chosen as the catalyst system, three terminal alkynes were conjugated with two different azides respectively, and then the new prepared fac-[188 Re(CO) 3 (H 2 O) 3]+ was coordinated to the six triazoles. The results showed that the radiochemical yields (RCY) of the conjugation of fac-[188 Re(CO) 3]+ with six triazoles were over 90%, and the triazoles showed high stability in phosphate-buffered saline and new-born calf serum. The preliminary biological evaluation results showed that the new 188 Re-labeling method via click chemistry could have general application in labeling bioactive molecules in high radiochemical yield and high specific activity for further SPECT research.
Graphene oxide(GO)nanosheets possess several advantages,such as a large surface,outstanding biocompatibility,and straightforward chemical modification capability.They also have great potential as a drugcarrier.In this article,we radiolabeled GO nanosheets with99mTc,which satisfies the potential needs of microSPECT imaging probes in pre-clinical and clinical research.GO nanosheets were synthesized through the modified Hummers’method,then GO nanosheets with azide group covalently functionalized in two steps were conjugated to DOTA(1,4,7,10-tetraazacyclododecane-N,N,N,N-tetraacetic acid)and functionalized with an alkynyl group by means of click chemistry.Then through the addition and reduction of technetium-99m,the99mTc-DOTA-GO were attained.DOTA-conjugated GOs with lateral dimensions of 500–600 nm were synthesized.Both atomic force microscopy(AFM)and FT-IR were performed to characterize the GO-DOTA.Labeling efficiency of GO-DOTA with99mTc was>90%and radiochemical purities were>96%with purification.We successfully synthesized graphene oxide derivatives,DOTA-conjugated GOs,via Click Chemistry,and it was labeled with99mTc for SPECT imaging.High radiolabeling efficiency makes GO nanosheets suitable platforms for future molecular imaging research.
