Biodistribution of 99mTc-labeled HER2-Targeting Affibody in Balb/C Mice

Eight 6-week-old Balb/C mice, weighing 18–22 g, were selected and randomly divided into two groups, including five in the experimental group and three in the control group, and their body weights were recorded respectively. Five Balb/C rats in the experimental group were injected with ^99mTc-(HE)₃Z_HER2:V2 18–25 μCi (0.3 ml) from the tail vein. Three rats in the control group were injected with the same volume of sterile normal saline from the tail vein. During the experiment, mice were given sufficient water and food and received sufficient light during the day. The survival and activity of the mice were observed every day for 1 week. At the same time (12:00 noon) on the first, third, fifth and seventh days, the weights of the mice in the experimental group and the control group were compared before and after the experiment. After weighing the body weight on the seventh day, the mice were anesthetized with chloral hydrate, then sacrificed and dissected. The color and shape of the organs of the mice in the experimental group were observed and compared with those in the control group. The dissected organs and tissues were sent to the pathology department for HE staining, and the microscopic structures of the organs of the mice in the experimental group and the mice in the control group were observed.