三种网孔结构组织工程肌腱支架增强体的性能

以聚乙交酯(PGA)复丝和聚丙交酯(PLA)复丝为原料进行合股编织,分别采用小口径圆纬机和手工编织的方法,制得纬平、方形和菱形3种网孔结构的组织工程肌腱支架增强体.探讨了3种支架增强体的延伸性、孔隙率、孔径、强力等性能,并研究了8星期体外降解试验过程中支架增强体的断裂强力、质量损失、厚度、口径及孔隙率等性能的变化规律.结果表明:方形网孔结构的支架增强体延伸性最小、孔隙率和孔径最大;3种支架增强体在降解过程中,前3星期断裂强力急剧下降,厚度有所增加;降解4~6星期后支架的质量损失显著增大,厚度迅速减小;孔隙率在降解过程中呈先减小后增大趋势,在3~4星期时孔隙率值最小;手工编织支架增强体的口径在降解过程中无明显变化,而纬平支架增强体的口径在降解前3星期逐渐减小,3星期后又逐渐增大.     

热定型对PGA单丝、编织线及其肌腱支架力学性能的影响

利用正交试验,研究了热定型工艺(温度、时间、热定型方式)对聚乙交酯(PGA)单丝及编织线力学性能的影响,并将经过热定型(55℃、拉伸定型5min)和未经热定型的PGA肌腱支架增强体置于温度为37℃、pH值为7.4的磷酸盐缓冲液中进行4星期的体外降解试验.研究结果表明:热定型温度和时间对PGA单丝及编织线力学性能影响较大.对于PGA单丝及编织线,当热定型温度为40~60℃、时间为3~5 min、采用拉伸定型方式时,其力学性能较好;体外降解试验表明,经过热定型的PGA肌腱支架增强体的力学性能优于未经热定型的肌腱支架增强体.     

Properties of Scaffold Reinforcement for Tendon Tissue Engineering in vitro Degradation

Four kinds of braided yarns were produced with different proportions of polyglycolic acid( PGA) and polylactic acid( PLA)multifilaments( 2PGA /1PLA, 2PGA /2PLA, 3PGA /1PLA, and3PGA /2PLA). A novel artificial plain stitch scaffold reinforcement was manufactured by braiding technology and knitting technology respectively. Tendon scaffold reinforcements were investigated for 8weeks in phosphate buffered solution( PBS)( pH = 7. 4) at 37 ℃.The degradation was studied with regard to the mass loss,tensile properties,grams per square meter( g /m2),thickness,caliber,and porosity of scaffold reinforcements. The experimental showed that during the process of 8-week degradation,the mass losses of scaffold reinforcements were small in the first 3-week,but they increased rapidly after 3-week,and the speeds tended to be small gradually after 6-week; the tensile properties dropped rapidly in the first 2-week; the grams per square meter and thicknesses speeded down obviously between 3-week to 6-week. The caliber and porosity of scaffold reinforcements first decreased and then increased gradually. The porosity can reach more than 97%.