高精度快速成型模型的制作精度及其体外细胞毒性

Preparation accuracy and in vitro cytotoxicity of models prepared by rapid prototyping

背景:快速成型技术在手术模拟与组织工程研究的应用日益广泛,而现场手术模拟和术前指导对模型的精度要求非常高,且在术中使用模型应要求其对人体无毒性。目的:评估不同后处理方法快速成型模型的成型精度及其细胞毒性。方法:采用选择性激光烧结技术制作标准圆柱体样品模型,并经浸蜡或树脂处理后,测量模型的高度和底面直径,评估其成型精度。然后采用噻唑蓝法研究不同后处理的模型件对小鼠成纤维细胞L929和小鼠前成骨细胞MC3T3-E1的毒性作用。实验分为石蜡处理组、树脂处理组、阴性对照组(未处理模型)、空白对照组(新鲜培养基)及阳性对照组(体积分数5%的DMSO),培养2d后,490nm处测量吸光度,并计算其相对增殖率和评价细胞毒性等级。结果与结论:浸蜡、树脂处理后的模型以及模型原件的精度为95%～97%,误差为0.5～1mm。模型浸提液培养L929和MC3T3-E1细胞2d后,各实验组的细胞相对增殖率均大于80%,石蜡处理后的快速成型模型对L929和MC3T3-E1有较低的毒性作用,而树脂处理和未处理的模型对这两种细胞均无毒性作用,细胞毒性均为0～1级。

BACKGROUND：Rapid prototyping technology has been widely used in surgery simulation and tissue engineering research.However,spot surgical stimulation and preoperative instruction on accuracy of model is very high,and the model in the operation should require its avirulence to humans.OBJECTIVE：To evaluate the accuracy and cytotoxicity of the rapid prototyping models with different post treatment.METHODS：Standard cylindrical models were prepared by selective laser sintering method,followed by paraffin or resin treatment,the height and bottom diameter of the models was measured and its accuracy was assessed.Then,MTT method was used to study the cytotoxicity of model on mouse fibroblast L929 and mouse preosteoblast MC3T3-E1.The experiment was divided into five groups：paraffin-treatment group,resin-treatment group,negative control group （non-treatment sample）,blank group （flesh DMEM medium）,and positive control group （5% （v/v） DMSO）.After 2 days culturing,the absorbance of cells at 490 nm was tested,the relative growth rate was calculated and the cytotoxicity grade of models was evaluated.RESULTS AND CONCLUSION：The accuracy and error of models treated by paraffin,resin and the original model was 95%-97% and 0.5-1 mm respectively.After 2 days L929 and MC3T3-E1 cells cultured by leaching liquor of models,the relative growth rates of cells were more than 80% in each group.Moreover,rapid prototyping models treated by paraffin had low cytotoxicity on L929 and MC3T3-E1 cells,while resin-treatment and non-treatment models had no cytotoxicity on L929 and MC3T3-E1 cells,the grade of cytotoxicity was 0-1.