牡蛎壳细胞毒性和遗传毒性的生物相容性评价

Cytotoxicity and genotoxicity of oyster shell: A biocompatibility evaluation

背景：研究资料表明牡蛎壳是一种新的根管充填材料。根据中国医药行业标准，细胞毒性试验和遗传毒性试验是临床应用前生物学评价的初级筛选试验。目的：评价牡蛎壳粉末的细胞毒性和遗传毒性。设计、时间及地点：对比观察实验，于2008—04／07在北京大学口腔医学院材料研究室完成。材料：牡蛎壳粉末由中国科学院海洋研究所提供。用于细胞毒性检验的L929细胞株和遗传毒性检验的实验菌株——组氨酸营养缺陷型鼠伤寒沙门氏菌TA97，TA98，TA100，TA102由中国药品生物制品检定所提供。方法：制备牡蛎壳粉末0．5，1，2倍浸提液。分别采用分子滤过法和鼠伤寒沙门氏菌回复突变试验（Ames试验）的平板掺入法，对浸提液进行细胞毒性和遗传毒性检测。主要观察指标：测量经琥珀酸脱氢酶作用后微孔滤膜的褪色面积和各平皿中细菌回变菌落数。结果：分子滤过法实验显示材料与成纤维细胞接触2h，实验材料组的滤膜褪色面积与阴性对照结果一致，均未见滤膜褪色，细胞毒性为0级。实验材料与成纤维细胞接触24h，实验材料组的滤膜未染色区直径为1．0-20mm，褪色区面积达1～3mm2，细胞毒性为1级，表明实验材料对细胞会产生轻度毒性作用，但仍属合格范围。Ames实验显示各实验材料组菌落回变数均未高于相应菌株白发回变菌落数的2倍，且无剂量反应关系，结果为阴性。结论：牡蛎壳粉末对机体没有明显的细胞毒性和遗传毒性作用。

BACKGROUND： Oyster shell has been recently reported as a new root canal filling material; therefore, it needs primary biological evaluation, Le., cytotoxicity test and genotoxicity test, before clinical application. OBJECTIVE： To evaluate cytotoxicity and genotoxicity of oyster shell powder. DESIGN, TIME AND SETTING： A contrast observational study was performed at the Materials Laboratory, School of Stomatology of Poking University from April to July 2008. MATERIALS： Oyster shell powder was provided by Institute of Oceanology, Chinese Academy of Sciences; L929 cell strain and Salmonella typhimurium TA97, TA98, TA100, and TA102 were provided by the National Institute for the Control of Pharmaceutical and Biological Products. METHODS： Oyster shell diffusion was prepared based on the times of 0.5, 1, and 2. According to the standards of biological evaluation of dental materials, the cytotoxity and genotoxicity of oyster shell were evaluated with molecule filter test and Ames test. MAIN OUTCOME MEASURES： Fading area of the film induced by succinic dehydrogenase and amount of spontaneous revertants. RESULTS： After 2 hours, the results indicated that fading area of the film in the experimental group was the same as negative control, i.e., fading was not found in the film, and cytotoxicity was grade 0. After 24 hours, diameter of non-stained film was 1.0-2.0 mm, fading area was 1-3 mm2, and cytotoxicity was grade 1, suggesting that the material had light cytotoxity that was still qualified. The spontaneous revertant test indicated that the mutagenicity of experimental groups was no more than 2 times of the control groups, suggesting there was no dose-dependence. CONCLUSION： Oyster shell powder has no cytotoxicity and genotoxicity on the organism.