Department of Oral and Maxillofacial Surgery, College of Stomatology, Guangxi Medical University, Nanning 530021, China; Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Nanning 530021, China.
Guangxi Key Laboratory of Manufacturing System and Advanced Manufacturing Technology, School of Mechanical Engineering, Guangxi University, Nanning 530004, China.
Int J Biol Macromol. 2023 Jul 1;242(Pt 1):124728. doi: 10.1016/j.ijbiomac.2023.124728. Epub 2023 May 5.
Polylactic acid (PLA) has been extensively used as a bone scaffold material, but it still faces many problems including low biomineralization ability, weak cell response, low mechanical properties, etc. In this study, we proposed to utilize the distinctive physical, chemical and biological properties of a natural biomineral with organic matrix, pearl powder, to enhance the overall performance of PLA bone scaffolds. Porous PLA/pearl composite bone scaffolds were prepared using fused deposition modeling (FDM) 3D printing technology, and their comprehensive performance was investigated. Macro- and micro- morphological observation by the optical camera and scanning electron microscopy (SEM) showed the 3D printed scaffolds have interconnected and ordered periodic porous structures. Phase analysis by X-ray diffraction (XRD) indicated pearl powder was well composited with PLA without impurity formation during the melt extrusion process. The mechanical test results indicated the tensile and compressive strength of PLA/pearl composite scaffolds with 10 % pearl powder content yielded the highest values, which were 15.5 % and 21.8% greater than pure PLA, respectively. The water contact angle and water absorption tests indicated that PLA/pearl showed better hydrophilicity than PLA due to the presence of polar groups in the organic matrix of the pearl powder. The results of the simulated body fluid (SBF) soaking revealed that the addition of pearl powder effectively enhanced the formation and deposition of apatite, which was attributed to the release of Ca from the dissolution of pearl powder. The cell culture of bone marrow mesenchymal stem cells (BMSCs) indicated that PLA/pearl scaffolds showed better cell proliferation and osteogenic differentiation than PLA due to the stimulation of the biological organic matrix in pearl powder. These outcomes signify the potential of pearl powder as a natural biomineral containing bio-signal factors to improve the mechanical and biological properties of polymers for better bone tissue engineering application.
聚乳酸（PLA）已被广泛用作骨支架材料，但仍面临许多问题，包括生物矿化能力低、细胞反应弱、机械性能低等。在这项研究中，我们提出利用天然生物矿化物质珍珠粉独特的物理、化学和生物学特性来增强 PLA 骨支架的整体性能。采用熔融沉积建模（FDM）3D 打印技术制备多孔 PLA/珍珠复合骨支架，并对其综合性能进行了研究。通过光学相机和扫描电子显微镜（SEM）的宏观和微观形貌观察，发现 3D 打印支架具有相互连接和有序周期性多孔结构。X 射线衍射（XRD）的相分析表明，珍珠粉在熔融挤出过程中与 PLA 很好地复合，没有杂质形成。力学测试结果表明，添加 10%珍珠粉的 PLA/珍珠复合支架的拉伸和压缩强度分别比纯 PLA 提高了 15.5%和 21.8%。水接触角和吸水率测试表明，由于珍珠粉有机基质中存在极性基团，PLA/珍珠的亲水性优于 PLA。模拟体液（SBF）浸泡结果表明，由于珍珠粉的溶解释放 Ca，添加珍珠粉可有效促进磷灰石的形成和沉积。骨髓间充质干细胞（BMSCs）的细胞培养表明，由于珍珠粉中生物有机基质的刺激，PLA/珍珠支架的细胞增殖和成骨分化能力优于 PLA。这些结果表明，珍珠粉作为一种天然生物矿化物质，含有生物信号因子，有望改善聚合物的力学和生物学性能，从而更好地应用于骨组织工程。
