羟基磷灰石的表面改性及其对聚乳酸基多孔支架性能的影响

分别采用柠檬酸和硬脂酸对纳米羟基磷灰石（n-HA）进行表面处理，并利用TGA、FTIR、XPS等研究了不同改性剂的改性效果，发现柠檬酸和硬脂酸能够成功接枝在n-HA表面，但硬脂酸的接枝率更高。将柠檬酸改性的n-HA与聚乳酸（PLA）共混制备复合材料，通过SEM观察发现，制备的n-HA/PLA复合材料在n-HA粉体添加量不超过20wt%时，经处理后的n-HA粉体在基体中分散均匀，两相界面处结合紧密。同时研究了n-HA/PLA复合材料制备多孔骨支架的3D打印成型工艺，并测试了其力学性能，结果表明，采用熔融沉积3D打印技术制备的支架有良好的压缩模量，但达到10%形变时所承受的压缩强度与PLA相比仍然有一定差距。

Surface modification of hydroxyapatite and its influences on the properties of poly(lactic acid)-based porous scaffolds

Surface modifications of nano-hydroxyapatite (n-HA) were conducted in this study by using citric acid and stearic acid, respectively. The effects of different modifiers on the properties of n-HA were characterized by TGA, FTIR, XPS, and etc. The relevant results show that both citric acid and stearic acid could be successfully grafted onto the surface of hydroxyapatite, while the grafting ratio of stearic acidis relatively higher than that of citric acid. The composites were prepared by mixing PLA matrix with citric acid grafted n-HA.Through SEM, it is observed that the as-prepared composites containing n-HA powders less than 20wt% possess a uniform dispersibility and good inorganic/organic interfacial adhesion.The porous scaffold consisting of n-HA/PLA composites was prepared by 3D printing craft. The mechanical property evaluation results indicate that the as-prepared n-HA/PLA scaffold obtained from the fused deposition modeling 3D printing technique has a satisfactory compression modulus, although its compressive strength at 10% deformation is relatively lower than that of neat PLA scaffold.