可降解镁锌合金的细胞毒性和溶血实验

背景：自主设计的可降解镁锌合金既保持了镁合金与人骨接近的密度和弹性模量,又排除了商业镁合金中铝和稀土元素的毒性。目的：评价自制可降解Mg-6wt%Zn合金的细胞相容性。设计、时间及地点：对比观察实验,于2007-11/2008-03在上海交通大学附属第六人民医院中心实验室完成。材料：可降解Mg-6wt%Zn合金由上海交通大学材料科学与工程学院研制,密度1.82g/cm3,弹性模量44GPa。细胞毒性实验所用L-929细胞由中国科学院典型培养物保藏委员会细胞库提供。溶血实验所用血取自成年雄性新西兰大白兔。方法：将Mg-Zn合金浸提液稀释成100%,50%,10%,加入96孔板里培养L-929细胞,并设单纯的DMEM培养液为阴性对照组,加入0.64%苯酚的DMEM培养液为阳性对照组。主要观察指标：分别在第2,4,7天用MTT比色法定量测试材料对L-929细胞相对增殖率的影响,并根据ISO10993-5：1999标准评估细胞毒性。应用倒置显微镜观察细胞培养2,4,7d后形态和生长状况。按照ISO10993-4：2002标准,通过对材料与兔血红细胞在体外接触过程中,所致红细胞溶解和血红蛋白游离程度的测定,评价材料的体外溶血性。结果：随着培养时间的增加,细胞形态保持正常,数量明显增多,不同浓度镁锌浸提液中细胞生长形态与阴性对照并无明显差异。可降解镁锌合金对L-929细胞无明显毒性作用,毒性评价为0～1级。可降解镁锌合金对血液的溶血率为3.4%,小于标准规定的5%,属于无溶血反应。结论：可降解镁锌合金无明显细胞毒性,细胞相容性较好。

Cytotoxicity and hemolytic properties of biodegradable Mg-Zn alloy

BACKGROUND:A novel biodegradable Mg-Zn alloy has been designed,in which the density and the Young's modulus are proximal to human bone,at the same time,it depletes the toxicity of aluminium and rare earth element in commercial magnesium alloys.OBJECTIVE:To evaluate the cytocompatibility of biodegradable Mg-Zn alloy.DESIGN,TIME AND SETTING:Contrast study was performed in the central laboratory of the Sixth People's Hospital of Shanghai Jiao Tong University between November 2007 and March 2008.MATERIALS:The Mg-6wt%Zn was prepared by School of Materials Science and Engineering of Shanghai Jiao Tong University,with the density was 1.82 g/cm3 and the Young's modulus was 44 GPa.L-929 cells for cytocompatibility test were provided by Chinese Academy of Science Type Culture Collection.Ten male New Zealand rabbits were employed in the hemolysis test.METHODS:The Mg-Zn alloy extraction medium was prepared by serial dilutions with fresh medium to 10%,50% and 100%.The experiments were carried out in a 96-well tissue-culture plate.Simple DMEM culture solution was taken as negative controls,while DMEM culture solution supplemented with 0.64% phenol served as positive controls.MAIN OUTCOME MEASURES:Relative proliferation rate of L-929 cells was determined at 2,4 and 7 days with MTT assay.The cytotoxicity of Mg-Zn alloy was evaluated according to ISO 10993-5:1999.The L-929 cell morphology and growth at 2,4 and 7 days were determined under inverted microscope.Based on ISO 10993-4:2002,hemolysis in vitro was evaluated through measuring erythrocyte lysis and ferrohemoglobin freeing degree with indirect contact method.RESULTS:The number of L-929 cells increased significantly and the morphology was not changed.The growth and morphology of cells in different Mg-Zn extraction medium had no difference from negative control group.Cytotoxicity test showed that biodegradable Mg-Zn alloy did not have obvious toxicity on L-929 cells,and the cytotoxicity of these extracts was in grade 0-1.Hemolysis test suggested that the Mg-Zn alloys did not have obvious hemolysis reaction,and the hemolysis index was 3.4%,which was less than the national standard (5%).CONCLUSION:The Mg-Zn alloys do not have obvious cytotoxicity and hemolysis reaction,which demonstrate that Mg-Zn alloys have good cytocompatibility.