D,L-聚乳酸基形状记忆聚合物的生物安全性和细胞相容性

背景：课题组前期实验研制了输卵管避孕器材料D, L-聚乳酸基形状记忆聚合物，依据国内《生物材料和医疗器材生物学评价技术要求》规定，植入体内的组织工程材料必须进行生物安全评价和细胞相容性实验。 目的：观察D, L-聚乳酸基形状记忆聚合物的生物安全性。 方法：①内毒素实验：在鲎试剂中分别加入聚合物浸提液、内毒素工作标准品溶液和细菌内毒素检查用水。②致敏实验：在昆明小鼠肩胛骨内侧分别注射聚合物浸提液+弗氏完全佐剂+生理盐水、弗氏完全佐剂+生理盐水，通过皮内诱导、局部诱导和激发阶段，观察动物激发部位皮肤红斑和水肿反应程度。③急性毒性实验：分别在昆明小鼠腹腔注射100%，50%，25%聚合物浸提液及生理盐水。④细胞增殖MTT实验：直接法为将人脐静脉内皮细胞分别接种于聚合物膜、聚乳酸与玻璃片上；间接法为将人脐静脉内皮细胞分别接种于聚合物浸提液、丙烯酰胺溶液及1640培养液。 结果与结论：D, L-聚乳酸基形状记忆聚合物材料无细菌污染状况，符合生物安全标准，无致敏性及毒性，并且具有较好的细胞相容性。

Shape-memory polymer based on D,L-poly(lactic acid): Biosecurity and cytocompatibility

BACKGROUND: Previous experiments have prepared shape memory polymer based on D,L-poly(lactic acid). According to domestic technical requirements for biologically evaluating biomaterials and medical equipments, tissue-engineered grafts must be subjected to preclinical experiment for biosecurity and cytocompatibility evaluation. OBJECTIVE: To observe the biosecurity of the shape memory polymer based on D,L-poly(lactic acid). METHODS: (1) Bacterial endotoxin test: polymer extract, endotoxin working standard solution and checking standard water were added into limulus reagent, respectively. (2) Sensitization test: Polymer extract + Freund’s complete adjuvant + physiological saline and Freund’s complete adjuvant + physiological saline were injected into the scapula of Kunming mice. After induction by intradermal injection, local induction and excitation, stimulate skin erythema and edema degree were observed in animals. (3) Acute toxicity test: Kunming mice received intraperitoneal injection of 100%, 50%, 25% polymer leaching solution and physiological saline, respectively. (4) 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay for cell proliferation: The direct method was that human umbilical cord vascular endothelial cells were inoculated onto the polymer film, lactic acid and glass, respectively; the indirect method was that human umbilical cord vascular endothelial cells were inoculated into the polymer leaching solution, acrylamide solution and 1640 culture solution. RESULTS AND CONCLUSION: This shape memory polymer based on D,L-poly(lactic acid) is free of bacterial contamination in compliance with the biosecurity standards, and it has no allergenic and toxicity but has good cytocompatibility.