杜仲胶复合义齿软衬材料的研制及细胞毒性检测

目的:利用杜仲胶的优良特性,制备高弹性杜仲胶复合义齿软衬材料,检测其相关物理学性能和细胞毒性,探讨用于临床的可能性。方法:参考现有弹性杜仲胶配方和医用橡胶配方,以硬度、拉伸强度和断裂伸长率为力学性能观察指标,确定材料各主要成分的种类和用量,制备杜仲胶复合义齿软衬材料。应用四甲基偶氮唑蓝(MTT)方法,检测和比较各组杜仲胶复合义齿软衬材料、丙烯酸自凝软衬材料和Silagum硅橡胶义齿软衬材料的50%浸提液对体外培养细胞L929的毒性作用,采用SPSS 16.0软件包对数据进行统计学分析。结果:橡胶基质的种类和加入共混比例对杜仲胶复合义齿软衬材料的力学性能有显著影响,加入杜仲胶显著提高了顺丁橡胶的生胶强度,硬度、拉伸强度和断裂伸长率随之升高。MTT检测结果显示,各组杜仲胶复合义齿软衬材料对L929细胞无毒性,与丙烯酸自凝软衬材料和Silagum硅橡胶义齿软衬材料相比,5组杜仲胶复合义齿软衬材料在2、4、7 d时的毒性级别基本维持在1级,仅70:30组在7 d时达到2级。Silagum硅橡胶软衬材料和各组杜仲胶复合义齿软衬材料在2、4、7 d时的细胞相对增殖率均显著高于同等条件下的丙烯酸自凝软衬材料(P<0.05)。结论:杜仲胶与顺丁橡胶共混比例为70:30时,适量添加氧化锌、氧化镁、硬脂酸、升华硫、促进剂CZ、防老剂,可制备出力学性能适宜的高弹性杜仲胶复合义齿软衬材料。杜仲胶复合义齿软衬材料对体外培养的小鼠成纤维细胞L929无毒性,初步认为其生物相容性良好。

Preliminary development and cytotoxicity of Eucommia ulmoides gum composite soft denture liner

PURPOSE: To prepare a soft lining material with high elastic on the basis of excellent characteristics of Eucommia ulmoides gum, and explore its basic physical performance and cytotoxity. METHODS: Basic formula was used based on the existing formula of elastic Eucommia ulmoides gum and medical rubber, then hardness, tensile strength and elongation at break were investigated to determine the final formula of the material, named Eucommia ulmoides gum composite soft denture liner. L929 mouse fibroblasts cultured in vitro were used to detect the toxic effects of 50% of leaching solution released from three kinds of denture soft lining materials by MTT assay. Statistical analysis was performed using SPSS16.0 software package. RESULTS: The kinds and blending proportion of rubber matrix had significant impact on mechanical properties of Eucommia ulmoides gum composite soft denture liner, the addition of Eucommia ulmoides gum significantly increased the hardness, tensile strength and elongation at break of the butadiene rubber. MTT assay showed Eucommia ulmoides gum composite soft denture liner did not have cytotoxicity on L929 mouse fibroblasts. The toxicity levels of 5 groups of Eucommia ulmoides gum composite soft denture liner in the 2nd, 4th, 7th day were maintained in the first stage, only 70:30 group reached the second stage on the 7th day. The cell relative appreciation rate of Silagum and 5 groups of Eucommia ulmoides gum composite soft denture liner in 2nd, 4th, 7th day were significantly higher than that in the self-curing acrylic soft lining material (P<0.05). CONCLUSIONS: Eucommia ulmoides gum and butadiene rubber blend ratio of 70:30, adding appropriate amount of zinc oxide, magnesium, stearic acid, sublimed sulfur, CZ, antioxidants, can get optimum mechanical properties. Eucommia ulmoides gum composite soft denture liner has no effect on L929 fibroblasts proliferation, indicating good biocompatibility.