HA-PLA和Zn掺杂HA-PLA的界面结构及性能模拟

Simulation of interfacial structures and mechanical properties of hydroxyapatite-polylactic acid and Zn-doped hydroxyapatite-polylactic acid

人工合成的锌掺杂羟基磷灰石(Zn-doped hydroxyapatite,ZnHA)具有良好的生物亲和性、生物相容性、生物活性和骨传导作用,可作为一种优良的硬组织替代材料,但因有断裂韧性低、脆性高和抗疲劳强度差等缺点,限制了其临床应用,因此通常在Zn HA中加入第二相或多相(聚合物,如聚乳酸(polylactic acid,PLA))以增强其力学性能.为分析HA-PLA界面间的相互作用,采用分子动力学法研究HA、缺陷HA和ZnHA的3个晶面(001)、(100)和(110)与PLA复合之后的体系,分析其力学性能.结果发现,Zn的掺入会使HA-PLA的弹性性能有所下降;与缺陷HA-PLA相比,Zn掺杂的HA-PLA仍具有较好的稳定性与弹性性能,且(110)晶面的弹性性能比其他两个晶面更好.

Synthetic Zn-doped hydroxyapatite(ZnHA)has good bio-affinity,biocompatibility,bioactivity and bone conduction,and it can be used as an excellent hard tissue substitute material.However,it has disadvantages of inherent low fracture toughness,high brittleness and poor fatigue strength,which limit its clinical applications.Therefore,the second phase or multiple phases such as polylactic acid(PLA)are usually added into ZnHA for enhancing its mechanical properties.In order to analyze the interfacial interactions of HA-PLA,molecular dynamics method is used to study the system of three crystal faces(001),(100)and(110)of HA,HA and ZnHA combined with PLA,respectively.The mechanical properties of the composites are also analyzed.It is found that the incorporation of Zn would reduce elastic performance of HA-PLA.However,compared with the defective HA-PLA,the Zn-doped HA-PLA still has better stability and elastic properties.Moreover,the elastic properties of(110)crystal plane are better than those of the other two crystal faces.