人发角蛋白复合聚乳酸棒的力学强度测试及体内降解观察

Mechanical strength and in vivo degradation of human hair keratin-polylactic acid composite rods

目的对自行研究的人发角蛋白复合聚乳酸(HHK-PLA)骨科内固定棒进行力学强度测试和动物体内降解研究。方法(1)利用MTS-858MiniBionix型生物力学测试机分别对20根HHK-PLA棒的剪切强度、弯曲强度和弯曲模量进行测试,了解HHK-PLA骨科内固定棒的力学性能。(2)36个HHK-PLA棒试件随机植入18只SD大鼠双侧脊旁皮下组织中,分别于术后1、2、4、8、12、16、20、24、28周取出,测量质量损失,了解HHK-PLA在大鼠体内的降解情况。结果(1)HHK-PLA骨科内固定棒具有良好的初始机械力学强度,其剪切强度为241MPa,弯曲强度为358MPa,弯曲模量为13GPa。(2)HHK-PLA在大鼠体内可以良好的降解,早期降解较慢,而晚期降解较快。结论HHK-PLA骨科内固定棒具有良好的初始力学强度,且在体内可以良好的降解,有望在将来用于四肢承重骨的内固定。

Objective To test the mechanical strengt h and observe the in vivo degradation of self-made human hair keratin-pol ylactic acid (HHK-PLA) composite rods designed for use in internal fixation. Met hods Twenty such HHK-PLA composite rods were tested for shear strength, bending strength and bending modulus using the material testing system MTS-858 Mini Bionix. A total of 36 samples of HHK-PLA composite rods designed f or internal fixation of bone fracture were randomly implanted in dorsal subcuta neous tissue of 18 SD rats, and weight losses of these rods were measured 1, 2, 4, 8, 12, 16, 20, 24 and 28 weeks after the implantation to evaluate the in vivo degradation of the material. Results The initial shear strength of HHK-PLA rod was 241 MPa, bending strength 358 MPa, and bending modulus 13 GPa. The test dem onstrated a slower rate of degradation in SD rats in earlier period following i mplantation than in later period. Conclusion HHK-PLA composite rods have good i nitial mechanical strength and tolerable degradation in vivo, and may be used po tentially for internal fixation of the weigh-bearing bones of the limbs.