Yang Youwen, Wang Guoyong, Liang Huixin, Gao Chengde, Peng Shuping, Shen Lida, Shuai Cijun
Jiangxi University of Science and Technology, Nanchang 330013, China.
State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.
Int J Bioprint. 2018 Dec 12;5(1):148. doi: 10.18063/IJB.v5i1.148. eCollection 2019.
Additive manufacturing (AM) can obtain not only customized external shape but also porous internal structure for scaffolds, both of which are of great importance for repairing large segmental bone defects. The scaffold fabrication process generally involves scaffold design, AM, and post-treatments. Thus, this article firstly reviews the state-of-the-art of scaffold design, including computer-aided design, reverse modeling, topology optimization, and mathematical modeling. In addition, the current characteristics of several typical AM techniques, including selective laser sintering, fused deposition modeling (FDM), and electron beam melting (EBM), especially their advantages and limitations are presented. In particular, selective laser sintering is able to obtain scaffolds with nanoscale grains, due to its high heating rate and a short holding time. However, this character usually results in insufficient densification. FDM can fabricate scaffolds with a relative high accuracy of pore structure but with a relative low mechanical strength. EBM with a high beam-material coupling efficiency can process high melting point metals, but it exhibits a low-resolution and poor surface quality. Furthermore, the common post-treatments, with main focus on heat and surface treatments, which are applied to improve the comprehensive performance are also discussed. Finally, this review also discusses the future directions for AM scaffolds for bone tissue engineering.
增材制造（AM）不仅可以为支架获得定制的外部形状，还能制造多孔内部结构，这两者对于修复大段骨缺损都非常重要。支架制造过程通常包括支架设计、增材制造和后处理。因此，本文首先综述了支架设计的最新进展，包括计算机辅助设计、逆向建模、拓扑优化和数学建模。此外，还介绍了几种典型增材制造技术的当前特点，包括选择性激光烧结、熔融沉积建模（FDM）和电子束熔炼（EBM），特别是它们的优缺点。特别是，选择性激光烧结由于其加热速率高和保温时间短，能够获得具有纳米级晶粒的支架。然而，这一特性通常会导致致密化不足。FDM可以制造具有相对较高孔隙结构精度但机械强度相对较低的支架。具有高束-材料耦合效率的EBM可以加工高熔点金属，但它的分辨率低且表面质量差。此外，还讨论了用于改善综合性能的常见后处理，主要侧重于热处理和表面处理。最后，本综述还讨论了骨组织工程增材制造支架的未来发展方向。
