低温快速成型3D打印磁性纳米复合人工骨的性能测定

摘要

目的 利用低温快速成型技术的可控性、三维多孔立体结构的优点,制备骨组织修复材料磁性纳米多孔复合人工骨支架材料(n-HA/PLLA/Fe2O3),并检测其力学和降解性能.方法 低温快速成型仪分别制备不同成分比例的n-HA/PLLA/Fe2O3,再通过乙醇浸泡法测定支架孔隙率,采用电子试验机通过检测抗弯,抗压,弹性模量评价支架力学性能,通过电镜观察支架超微结构,浸泡磷酸盐缓冲液(PBS)进行降解试验,观察降解液的pH值变化,材料力学性能的变化.结果 n-HA和Fe2O3的比例增加,复合支架材料的拉伸强度减弱,弯曲强度在n-HA和Fe2O3的质量分数为10%时达到峰值(111.9 MPa),弹性模量随着n-HA和Fe2O3质量分数的增加而增大.在n-HA和Fe2O3含量为5%时出现大量的韧窝,孔隙率为83%;在n-HA和Fe2O3含量为10%断裂表面凹凸不平,孔隙率达到90%以上;在n-HA和Fe2O3含量为15%以上时断口又变得越来越平整,孔隙率在80%左右.随着降解时间的延长,支架材料的力学性能也一定程度的衰减.结论 复合人工骨支架材料的制备比例中,通过不同组分的筛选和测定,设定最佳的组分配比来制备出性能优良的支架材料.当n-HA和Fe2O3成分为10%时,该磁性纳米多孔复合人工骨支架材料具有更好的生物力学性能以及可降解性能.%Objective To prepare porous magnetic nanocomposite artificial bone scaffolds (n-HA/PLLA/Fe2O3) using a low-temperature rapid prototyper, and to characterize the properties of the scaffold. Methods A low-tem-perature rapid prototyper was applied to fabricate the porous magnetic nanocomposite scaffolds with different mass ra-tios of n-HA/PLLA/Fe2O3. The medium (ethanol) immersion assay was used to examine the scaffold porosity. Mechani-cal tests, including bending, compression and elastic modulus, were performed to investigate the scaffold mechanical properties. A scanning electron microscope was used to observe the scaffold microstructures. Phosphate buffer solution (PBS) soaking was performed to study the scaffold degradation behavior by monitoring the changes of pH value and the scaffold mechanical properties. Results With the increase of the n-HA and Fe2O3 content, the tensile strength of scaf-fold gradually decreased, while the elastic modulus increased. The bending strength reached the maximum (111.9 MPa) when the mass fraction of n-HA and Fe2O3 was 10%, at which time the scaffold with a porosity of 90%showed a rough fracture surface. The scaffold had a porosity of 83%when the mass fraction of n-HA and Fe2O3 was 5%, with a large number of dimples being observed. If the mass fraction increased to 15%, a porosity of 80%was obtained and the fac-ture surface became relatively smooth. In the degradation study, the pH value of the medium decreased with time and the scaffold mechanical properties had certain attenuation. Conclusion The scaffold of 10%n-HA and Fe2O3 obtained bet-ter mechanical properties and degradation behavior, which would facilitate the selection of the porous magnetic nano-composite artificial bone scaffold with best performance.