The work is to evaluate the liver-targeting ability of 99Tcm-GHSA-IFNα2b. 99Tcm-GHSA-IFNα2b was prepared by the reduction of Na99TcmO4 with SnCl2. Effects of the SnCl2 or GHSA-IFNα2b amount and pH value on the labeling yield of 99Tcm-GHSA-IFNα2b were investigated. The biodistribution was studied with ICR mice. 0.2 mL(0.286 MBq) 99Tcm-GHSA-IFNα2b solution containing 2 μg GHSA-IFNα2b was iv injected to each animal through the tail. The mice were decapitated at 5

10

15

30

60 and 120 min. The organs of interest were excised

weighed

and counted. The ID%/organ and ID%/g were calculated. Liver scan of 99Tcm-GHSA-IFNα2b was performed on a rat . The results showed that labeling yield of 99Tcm-GHSA-IFNα2b could be over 90% under the following labeling conditions: pH 3.0 ~ 4.5

over 0.3 mg of GHSA-IFNα2b

3 μg~60 μg of SnCl2

and 30 min labeling at 37°C. Biodistribution in mice showed a peak of liver uptake of 99Tcm-GHSA-IFNα2b in 10 min after injection

being excreted mainly via the biliary system and gastrointestinal tract. Clear liver images were obtained in 15~30 min after injection. It can be concluded that GHSA-IFNα2b is a promising interferon with good liver-targeting ability

and 99Tcm-GHSA-IFNα2b is a potential hepatic receptor imaging agent.