新型聚乳酸与纳米羟基磷灰石复合人工骨的性能测试研究

The study of a new artificial bone consisted with polylactic acid and nano-hydroxyapatite

目的通过原位聚合法制备新型的聚乳酸与纳米羟基磷灰石复合材料,找到两者复合的最佳配比,从而得到理想的人工骨移植材料。方法采用原位聚合法按一定的配比(纳米羟基磷灰石质量分数分别为0,10%,20%,30%,40%)聚乳酸与纳米羟基磷灰石复合人工骨,对这类新型的人工骨进行性能测试,通过抗弯,抗压,弹性模量,电镜扫描,体外降解实验,观测该人工骨的力学性能、微观结构、纳米羟基磷灰石在聚乳酸中的分散情况以及复合材料的降解性能。结果 (1)力学测试显示:随着n-HA含量的增加,复合材料的拉伸强度逐渐减少。复合材料的弯曲强度在n-HA微粒的质量分数为20%时弯曲强度出现峰值(156.8 MPa)。复合材料的弯曲模量随着n-HA微粒质量分数的增加而增大。(2)SEM扫描显示:纯PDLLA材料断裂表面较平整;在n-HA含量为10%时出现大量的韧窝,明显的粗糙断裂面;在n-HA含量为20%断裂表面凹凸不平,形成大量的韧窝;在n-HA含量为30%以上时断口又变得越来越平整,尚有许多小的韧窝。(3)体外降解实验显示:随着降解时间的延长,降解液的pH值均逐渐降低,复合材料的力学性能也逐渐的产生一定的衰减。结论当n-HA含量为20%时,该人工骨复合材料有着更好的力学性能和降解性能,筛选出该种新型人工骨的最佳配比,制备出性能良好的PDLLA/n-HA复合人工骨材料。

Objective To prepare a new artificial bone material by in situ polymerization ofpolylactic acid and nano-hydroxyapatite. Methods According to a specified ratio （the mass fraction of nano-hydroxyapatite respectively was 0, 10%, 20%, 30%, and 40%）, polylactic acid and nano-hydroxyapatite were composed by in situ polymerization, followed by the testing of material parameters, including mechanical, ultrastructural, dispersional features in vitro. The degradation rate of composite material was detected. Results With the increase of n-HA content, the tensile strength of composite material decreased, but the elastic modulus increased. 20% of nano-hydroxyapatite content, made the best bending strength of composite material （156.8 MPa）. SEM scan showed that, the fracture surface of pure PDLLA was relatively smooth; 10% of nano-hydroxyapatite content induced obvious dimples on the fracture surface. 20% nano-hydroxyapatite content induced uneven fracture surface, with a large number of dimples. However, 30% of nano-hydroxyapatite content made the fracture surface more fiat. PH values of degradation liquid gradually reduced, as well the mechanical strength, following the extension of degradation. Conclusions Artificial bone material with 20% nano-hydroxyapatite content is ideal for its better mechanical properties and degradation properties.