PLLA和PLGA体内早期降解的对比研究  

A Comparative Study of Early Degradation of PLLA and PLGA Rods at Various Sites in Rabbit

作　　者：庞迪[1,2] 叶京兵[3] 陈栋梁[1] 李箭[3] 熊成东[1] 李庆[1] 

机构地区：[1]中国科学院成都有机化学所,成都610041 [2]中国科学院研究生院,北京100039 [3]四川大学华西医院,成都610041

出　　处：《生物医学工程学杂志》2010年第6期1298-1302,共5页Journal of Biomedical Engineering

摘　　要：为了考察不同的体内环境对材料早期降解行为的影响,采用自制左旋聚乳酸(PLLA)、聚乳酸-羟基乙酸共聚物(PLGA)内固定棒植入新西兰大白兔关节腔髌上囊与对侧股骨髁松质骨内。经过4、8、12和16周体内降解后,取出植入材料,考察分子量、剪切强度、质量损失以及热力学性能的变化。结果显示,PLGA降解比PLLA稍快。16周后,PLGA和PLLA特性黏度分别从初始的4.2和4.6下降到2.2和3.4左右;两种材料在16周内都保持了足够高的剪切强度(≥53 MPa)。PLGA在8周后,PLLA在12周后,质量损失速率有所加快,表明在自催化的作用下出现了加速降解的现象。研究结果显示,PLGA可以取代PLLA用于骨内固定,不同植入部位对PLLA或PLGA在16周内的早期降解行为没有显著影响。This study was designed to assess the effect of implantation site and environment on early in vivo degradation behaviors of poly（L-lactide）（PLLA） and poly（L-lactideco-glycolide）（PLGA） copolymer.The rods were implanted at two sites in each of 24 New Zealand White rabbits.The first site was within the suprapatellar bursa of the joint cavities（JC） and the second site was in the opposite condyles of femurs（CF）.Three rabbits of each group underwent explantation of rods after 4,8,12,and 16 weeks.At each interval,measures were taken to evaluate the molecular weight,shear strength,weight loss and thermal properties of PLLA and PLGA.It was found that PLGA degraded slightly faster than PLLA.After 16 weeks,PLLA＇s initial inherent viscosity of 4.6 decreased to about 3.4 in both implantation sites while that of PLGA decreased from 4.6 to about 2.2.Both PLGA and PLLA showed enough shear strength retention in 16 weeks（≥53MPa） within 16 weeks.Autocatalysis mechanism was confirmed by the fact of accelerated weight loss of PLGA after 8 weeks and of PLLA after 12 weeks.The results revealed that PLGA could be a promising candidate material as a replacement of PLLA in internal fixation of bone fractures,and no significant difference of early in vivo degradation behaviors between PLLA and PLGA was observed in regard to different implantation sites in 16 weeks.

关 键 词：左旋聚乳酸 聚乳酸-羟基乙酸共聚物 体内降解 内固定 

分 类 号：R318.08[医药卫生—生物医学工程]