筛选可注射型人工髓核材料的体外细胞毒性测试

Basic sieving of an injectable prosthetic nucleus pulposus by studying cytotoxicity in vitro

目的经体外细胞毒性测试初步筛选一类新型的聚醚型聚氨酯作为可注射型人工髓核材料。方法设置5个实验组：即样品1、2、3组为加入不同配比催化剂合成的软硬段配比不同的聚醚型聚氨酯；样品4组是不加催化剂，在37℃下经缓慢聚合而成的聚醚型聚氨酯；样品5组为单体有毒基团完全反应的聚醚型聚氨酯。另设1个对照组为不含材料浸提液的培养基。称取每组实验材料各0．6mg，经消毒后分别制成浸提液，经稀释50％后培养小鼠成纤维细胞（L929细胞），分别培养至第3天、4天、5天，使用3-（4，5-二甲基-2-噻唑）-2，5-二苯基溴化四唑（MTT）比色法比较材料组与对照组间酶联免疫分析法测得的490nnl处的0D值，计算细胞相对增殖率，来评价材料的细胞毒性。结果样品4组和样品5组与对照组相比，L929细胞相对增殖率没有显著性差异，细胞毒性分级属于o～1级；样品1-3组与对照组L929细胞相对增殖率比较，差异有统计学意义，细胞毒性1～2级，但细胞形态正常。结论未加催化剂的体内聚合聚氨酯材料没有细胞毒性，具有作为髓核替代材料的应用潜力。加入催化剂后快速聚合的材料毒性有待进一步测试。

To sieve a new type of polyether polyurethane as an injectable prosthetic nucleus pulpous through testing the cytotoxicity in vitro. Methods Five experimental groups were set as following： that sampies 1, 2, 3 groups were polyether-polyurethane polymerized of different ratio of soft and hard segment with different catalysts; group 4 was polyether polyurethane polymerized slowly at 37 cC without catalyst; group 5 was polyether polyurethane that toxic monomer responded completely. Additionally, a control group of culture medium was set without material extracts. Get 0.6 mg from each sample product and make into material extracts after disinfection, then dilution them by 50% and culture the mouse fibroblasts （cell L929） until 3 d, 4 d, 5 d, by Adopting 3-（4, 5-dimethyl-2-thiazolyl）-2, 5-diphenyl tetrazolium bromide （MTI＇） colorimetric method to compare the 490 nm OD between the materials and control groups obtained by enzyme linked immune analysis, calculate the RGR of cells, and then evaluating the cytotoxicity of the materials. Results The RGR of L929 cell in group 4 and group 5 have no significant difference compared to the control group. Cytotoxic levels were 0 to 1; difference of the RGR of L929 cell between group 1-3 and control group were statistically significant. Cytotoxic levels were 1 to 2, but the cell morphology was normal. Conclusion The material polymerized without catalyst does not show cytotoxicity, and has great potential to be used as a substitute for nucleus pulposus. The cytotoxicity of the materials polymerized with catalyst needs to be tested