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REVIEW ARTICLE

Additive manufacturing of bone scaffolds

Youwen Yang 1,2† , Guoyong Wang , Huixin Liang , Chengde Gao , Shuping Peng , Lida Shen and
1†
3
2
3
4
Cijun Shuai 1,2,5 *
1 Jiangxi University of Science and Technology, Nanchang 330013, China
2 State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China
3 College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, 210016 Nanjing, China
4 Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya School of Medicine, Central South
University, Changsha 410013, China
5 Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, China
†These authors contributed equally to this work.

Abstract: 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.

Keywords: Additive manufacturing; bone scaffolds; scaffolds design; post-treatments

*Correspondence to: Cijun Shuai, Central South University, China; shuai@csu.edu.cn
Received: June 09, 2018; Accepted: July 09, 2018; Published Online: December 12, 2018
Citation: Yang Y, Wang G, Liang H, et al., 2019, Additive manufacturing of bone scaffolds. Int J Bioprint, 5(1): 148. http://dx/doi.
org/10.18063/IJB.v5i1.148

1. Introduction in clinical surgeries to aid in the healing of these large
segmental bone defects. Data from the center for disease
Bone tissue is able to subject to biological remodeling control show that bone is the second most commonly
through a dynamic process of the absorption of mature graft tissue, with more than 2 million surgical operations
bone tissue by osteoclasts and subsequent generation of utilizing bone grafts annually . Autografts taken from the
[5]
new bone induced by osteoblasts [1,2] . Nevertheless, the patient-self are considered as the gold standard for bone
body usually cannot fulfill the self-repairing as a large repair . However, the size of the autograft is very limited.
[6]
segmental bone defect occurs, in which the bone defect Moreover, harvesting the autograft inevitably causes an
exceeds a critical size of about 10 mm . In this condition, additional surgical trauma associated with a serious risk
[3]
an external intervention is required to aid in the self- of morbidity at the donor site. Allografts taken from other
repairing by means of building bridges on the bone defect persons are an alternative and are in larger supply as
site . Therefore, bone grafts are extensively required compared with the autografts. However, they usually lead
[4]
Additive manufacturing of bone scaffolds. © 2019 Shuai. This is an Open-Access article distributed under the terms of the Attribution-NonCommercial
4.0 International 4.0 (CC BY-NC 4.0), which permits all non-commercial use, distribution, and reproduction in any medium, provided the original work is
properly cited.
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