Abstract: OBJECTIVE: To explore the use of tree shrews in the micronucleus test as an assay to evaluate medical devices. METHODS: 30 tree shrews were randomly divided into three groups:negative control, test sample (collagen implant) and positive control. Treated animals were each induced by two intraperitoneal injections of 10 mL/kg. Femoral bone marrow cells were removed from each animal to detect micronucleus rates, and to conduct other tests:blood biochemistry and electrolyte tests, spleen, liver and kidney organ coefficients and histopathological tests. At the same time,experiments were performed using mice as a reference for the system. RESULTS: The micronucleus rates from the negative control and the test sample groups of the tree shrews and that from mice were <5%. The difference in micronucleus rates between the test sample and the negative control groups were not significant (P > 0.05),but the difference between the positive control and the negative control groups were statistically significant (P < 0.01). The results of the tree shrew micronucleus test were consistent with those from the mice. Compared with the negative control group, the tree shrew blood routine, blood biochemistry, electrolyte and histopathological test results in the test sample group were not found to be abnormal. Compared with mice, the organ coefficient of tree shrews is closer to that of humans. CONCLUSION: Tree shrew can be used as an animal modal for micronucleus test evaluation,and tree shrew has the potential to be used as a biological evaluation of medical devices.

Key words: tree shrew, biological evaluation of medical devices, genotoxicity test, micronucleus test