聚乳酸/纳米羟基磷灰石复合微球的生物安全性评价

Biosafety evaluation of poly(lactic acid)/nano-hydroxyapatite composite microspheres

背景:纳米材料以及包含纳米相的医疗器械,因为纳米材料具有尺寸小、比表面积大等独特特性,可能会引发特殊的生物效应,其生物安全性成为人们关注的重点。目的:评价聚乳酸/纳米羟基磷灰石复合微球的生物安全性。方法:采用乳液溶剂挥发法制备聚乳酸/纳米羟基磷灰石复合微球。(1)细胞毒性实验:将聚乳酸/纳米羟基磷灰石复合微球浸提液与小鼠成纤维细胞共培养,同时设置空白对照(完全培养基)、阴性对照(高密度聚乙烯树脂浸提液)与阳性对照(二乙基二硫代氨基甲酸锌浸提液),采用MTT法评价细胞毒性;(2)致敏反应:将复合微球分别进行极性浸提和非极性浸提,进行豚鼠皮内诱导和激发实验,记录结果;(3)皮内反应:将复合微球进行极性浸提和非极性浸提,兔皮内注射后即刻及24,48,72 h,观察各注射部位状况;(4)全身急性毒反应:将复合微球分别进行极性浸提和非极性浸提,通过静脉和腹腔注射到KM小鼠体内,观察小鼠体质量变化;(5)热源反应:将复合微球进行极性浸提,通过耳缘静脉注射至兔体内,记录体温变化;(6)骨植入实验:将圆柱状的复合微球与高密度聚乙烯棒分别植入兔胫骨缺损部位,进行大体观察和局部组织病理学观察。结果与结论:(1)聚乳酸/纳米羟基磷灰石复合微球无细胞毒性、无致敏性、无皮内刺激反应、无全身急性毒反应,热源反应符合检测规定;复合微球植入兔胫骨缺损部位后,植入部位未见血肿、水肿、炎症等病变,组织学观察显示复合微球具有一定的骨组织修复能力;(2)骨结果显示,聚乳酸/纳米羟基磷灰石复合微球具有良好的生物安全性。

BACKGROUND:As nanomaterials and medical devices containing nanomaterials have unique characteristics such as small size and large specific surface area,which may lead to special biological effects,their biological safety has become the focus of attention.OBJECTIVE:To evaluate the biosafety of poly(lactic acid)/nano-hydroxyapatite composite microspheres.METHODS:Poly(lactic acid)/nano-hydroxyapatite composite microspheres were prepared by emulsion solvent evaporation.(1)Cytotoxicity test:Mouse fibroblasts were co-cultured with poly(lactic acid)/nano-hydroxyapatite composite microspheres extract.Blank control(complete medium),negative control(high-density polyethylene resin extract)and positive control(zinc diethyldithiocarbamate extract)were set.The cytotoxicity was evaluated by MTT assay.(2)Sensitization reaction:Polar and non-polar extraction of the sample,intradermal induction and excitation test were conducted,and the results were recorded.(3)Intradermal reaction:Polar extraction and non-polar extraction of composite microspheres were performed.Immediately,24,48 and 72 hours after intradermal injection,the status of each injection site was observed.(4)Acute systemic toxicity:The composite microspheres were extracted by polar extraction and non-polar extraction.After intravenous and intraperitoneal injection into the body of KM mice,the changes in body weight of mice were observed.(5)Pyrogen reaction:After polar extraction,the composite microspheres were injected through the ear vein into the rabbit to record changes in body temperature.(6)Bone implantation test:Cylindrical composite microspheres with high-density polyethylene rods were implanted into the tibial defects of rabbits for gross observation and local histopathological observation.RESULTS AND CONCLUSION:(1)The poly(lactic acid)/nano-hydroxyapatite composite microspheres had no cytotoxicity,sensitization,intradermal irritation,or acute systemic toxicity.The pyrogen reaction was in line with the test regulations.After the composite microspheres were implanted into the tibial defect of rabbits,no lesions such as hematoma,edema or inflammation were observed at the implantation site,and the histological observation showed that the composite microspheres had a certain ability of bone tissue repair.(2)Bone results show that poly(lactic acid)/nano-hydroxyapatite composite microspheres had good biosafety.