Page 47 - IJB-7-4

REVIEW ARTICLE

Advances in Filament Structure of 3D Bioprinted

Biodegradable Bone Repair Scaffolds

Chengxiong Lin , Yaocheng Wang , Zhengyu Huang , Tingting Wu , Weikang Xu ,
1
1,2
1
1
1,2
Wenming Wu , Zhibiao Xu *
2
1
1 National Engineering Research Center for Healthcare Devices, Guangdong Provincial Key Laboratory of Medical
Electronic Instruments and Polymer Products, Guangdong Medical Device Research Institute, Guangzhou 510500, China
2 School of Railway Tracks and Transportation, Wuyi University, Jiangmen 529020, China
Abstract: Conventional bone repair scaffolds can no longer meet the high standards and requirements of clinical applications
in terms of preparation process and service performance. Studies have shown that the diversity of filament structures of
implantable scaffolds is closely related to their overall properties (mechanical properties, degradation properties, and biological
properties). To better elucidate the characteristics and advantages of different filament structures, this paper retrieves and
summarizes the state of the art in the filament structure of the three-dimensional (3D) bioprinted biodegradable bone repair
scaffolds, mainly including single-layer structure, double-layer structure, hollow structure, core-shell structure and bionic
structures. The eximious performance of the novel scaffolds was discussed from different aspects (material composition,
ink configuration, printing parameters, etc.). Besides, the additional functions of the current bone repair scaffold, such as
chondrogenesis, angiogenesis, anti-bacteria, and anti-tumor, were also concluded. Finally, the paper prospects the future
material selection, structural design, functional development, and performance optimization of bone repair scaffolds.
Keywords: Bone repair scaffolds; Filament structure; 3D printing; Mechanical properties

*Correspondence to: Zhibiao Xu, School of Railway Tracks and Transportation, Wuyi University, Jiangmen 529020, China; 544260221@qq.com
Received: August 9, 2021; Accepted: September 3, 2021; Published Online: October 13, 2021

Citation: Lin C, Wang Y, Huang Z, et al., 2021, Advances in Filament Structure of 3D Bioprinted Biodegradable Bone Repair Scaffolds. Int J
Bioprint, 7(4):426. http://doi.org/10.18063/ijb.v7i4.426

1. Introduction allografts are prone to inactivation after ultraviolet (UV)
irradiation or freeze-drying treatment, resulting in low
At present, the number of patients with bone defects caused osteoinductivity, the problem of treatment failure due to
by tumors, infections, aging populations, or accidental host immune response [6-8] .
injuries shows an increasing trend. According to statistics, Bone repair scaffolds with wide source, easy
there are about 3 million new cases with bone injury fabrication and good osteogenic activity have provided
worldwide every year, pointing to the huge development new insight for bone defect treatment [9,10] . A good bone
space in the market of bone repair materials . Although repair scaffold should have the following basic properties:
[1]
bone tissue has the ability to recover and regenerate itself, (i) being biocompatible to avoid immune rejection after
bone defects such as fractures and microfractures that implantation in the patient ; (ii) having mechanical
[11]
exceed a critical threshold (usually >2 cm, depending on properties so that the scaffold can be a carrier in the
the anatomical site) cannot renew itself [2-4] . Autologous defect site ; (iii) having interconnected pore structure
[12]
bone transplantation is the “gold standard” for the and proper porosity because bone formation requires
[13]
treatment of bone defects in current clinical practice, but not only a large amount of space to adhere to growth
this treatment involves procedure that removes bone from factors, but also connected pores to supply the necessary
patient which has the problem of limited sources of bone nutrients and oxygen and provide channels for cell
[14]
tissue and the second surgery that brings greater pain to migration and blood vessel growth [15-17] ; and (iv) being
the patient . Compared with autologous bone grafts, biodegradable so that the implanted scaffold will degrade
[5]
© 2021 Lin, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License, permitting distribution and
reproduction in any medium, provided the original work is cited.
43