Abstract
INTRODUCTION: Alternative transgenic mouse models, such as rasH2, have been developed as to replace the traditional 2-year rodent carcinogenicity study. However, due to high cost, reliance on imports, and unpredictable supply chains, these transgenic mouse models have not yet been widely adopted for carcinogenicity evaluations of medical devices in China. METHODS: KI.C57-ras2.0 mice, which possess independent intellectual property rights in China, were employed to evaluate the carcinogenicity of a new hemodialyzer. A total of 110 KI.C57-ras2.0 mice were divided into three groups including positive control (PC) group, negative control (NC) group and sample extracts (SE) group. Animals in the PC group were injected with MNU intraperitoneally at the concentration of 75 mg/kg for a single time. Animals in the SE and NC group were injected intraperitoneally with sample solution and 0.9% sodium chloride, the injection volume was 20 ml/kg BW, 6 days per week, and the entire administration period was 26 weeks. RESULTS: The survival rates of mice in PC group, NC group and SE group were 16.7%, 93.3% and 92.0%, respectively. Tumour incidence rates were 100.00%, 13.33% and 12.00%; the incidences of benign tumour were 10.00%, 3.33% and 6.00%; the incidences of malignant tumour were 90.00%, 10.00% and 6.00%; the incidences of multiple tumour was 86.67%, 0.00% and 0.00%; the average number of tumours were 8.67 ± 5.97, 0.10 ± 0.31 and 0.10 ± 0.30, respectively. There was no statistical difference in the above indexes between SE group and NC group, and there was no significant correlation between tumour lesions of all genders in SE group. Therefore, there is no carcinogenicity in this hemodialyzer. CONCLUSIONS: This new hemodialyzer had no carcinogenicity under this experimental condition. This study also improved the biological evaluation system of medical devices. As an animal model with great application prospects, we believe that KI.C57-ras2.0 mice will be an indispensable model animal for the evaluation of medical devices in the future, and facilitated the marketing of new biomaterials and medical devices.