Wei Yihang, Zhao Dingyun, Cao Quanle, Wang Jing, Wu Yonghao, Yuan Bo, Li Xiangfeng, Chen Xuening, Zhou Yong, Yang Xiao, Zhu Xiangdong, Tu Chongqi, Zhang Xingdong
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China.
Department of Orthopaedics, West China Hospital of Sichuan University, Chengdu 610041, China.
ACS Biomater Sci Eng. 2020 Mar 9;6(3):1787-1797. doi: 10.1021/acsbiomaterials.9b01663. Epub 2020 Feb 20.
Digital light processing (DLP) is one of the additive manufacturing (AM) technologies suitable for preparation of high-performance ceramics. The present study provided an optimized formula to fabricate osteoinductive calcium phosphate (CaP) ceramics with high precision and controllable three-dimensional (3D) structure. Among the four surfactants, monoalcohol ethoxylate phosphate was the best one to modify the CaP powders for preparing the photocurable slurry with high solid loading and good spreading ability. By testing the photopolymerization property of the 60 wt % solid loading slurry, the appropriate processing parameters including the slice thickness (50 μm), exposure intensity (10.14 mW/cm), and exposure time (8 s) were set to perform the 3D printing of the ceramic green body in the DLP system. After the debinding and sintering, the final CaP ceramics were acquired. The stereomicroscope and SEM observation confirmed the high precision of the ceramics. The average compressive strength of the ceramics with 64.5% porosity reached 9.03 MPa. On only soaking in simulated body fluid for 1 day, an even layer of apatite formed on the ceramic surface. The cell culture confirmed that the ceramics could allow the good attachment, growth, and proliferation of murine bone marrow mesenchymal stem cells. After implantation into the dorsal muscles of beagle dogs for 3 months, abundant blood vessels and obvious ectopic bone formation were observed clearly by the histological evaluation. Therefore, with good bioactivity and osteoinductivity as well as high precision and adjustable mechanical strength, the 3D printed CaP ceramics in the DLP system could have good potential in customized bone-repairing applications.
数字光处理（DLP）是适用于制备高性能陶瓷的增材制造（AM）技术之一。本研究提供了一种优化配方，用于制造具有高精度和可控三维（3D）结构的骨诱导磷酸钙（CaP）陶瓷。在四种表面活性剂中，单醇乙氧基化磷酸盐是修饰CaP粉末以制备具有高固体负载量和良好铺展能力的光固化浆料的最佳表面活性剂。通过测试60 wt%固体负载量浆料的光聚合性能，设定了合适的工艺参数，包括切片厚度（50μm）、曝光强度（10.14 mW/cm）和曝光时间（8 s），以在DLP系统中进行陶瓷坯体的3D打印。经过脱脂和烧结后，获得了最终的CaP陶瓷。立体显微镜和扫描电子显微镜观察证实了陶瓷的高精度。孔隙率为64.5%的陶瓷的平均抗压强度达到9.03 MPa。仅在模拟体液中浸泡1天，陶瓷表面就形成了一层均匀的磷灰石。细胞培养证实，该陶瓷能够使小鼠骨髓间充质干细胞良好附着、生长和增殖。植入比格犬背部肌肉3个月后，组织学评估清楚地观察到丰富的血管和明显的异位骨形成。因此，DLP系统中3D打印的CaP陶瓷具有良好的生物活性和骨诱导性，以及高精度和可调节的机械强度，在定制骨修复应用中具有良好的潜力。
