Page 180 - IJB-10-4

International

Journal of Bioprinting

RESEARCH ARTICLE
Manufacturing and degrading features of

3D-printed porous spinal interbody fusion cages

Zhiwei Jiao , Pengfei Chi , Hanlin Zou , Yuan Yu , Weimin Yang , Hao Liu ,
1
1,2
3,4
1,2
1
1
Dong Chen , and Haibo Zou *
3
3
1 College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology,
Beijing, China
2 State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology,
Beijing, China
3
Spine Division of Orthopaedic Department, China-Japan Friendship Hospital, Beijing, China
4 Department of Orthopedics, Capital Medical University, Beijing, China
Abstract
Spinal fusion operations are often utilized to address disc degeneration, vertebral
slippage, instability, and trauma, and interbody fusion cages have been widely
employed in these procedures. The fundamental aim of an interbody fusion cage
is to give immediate interbody support, height, and biomechanical stability of the
spinal space to enable bone development in the fused area. With the aim to address
shortcomings of the currently commonly used clinical spinal interbody fusion cages,
such as non-osteogenic activity, non-resorbability, biomechanical mismatch, etc.,
composites made of polycaprolactone (PCL) were prepared in this study, with the
*Corresponding author: addition of hydroxyapatite (HA) that possesses both osteoinductive properties and
Haibo Zou enhanced mechanical strength as a functional filler. An innovative bi-directional
(dr.haibozou@gmail.com) variable meso-structure scheme is proposed. The porous degradable spinal interbody
Citation: Jiao Z, Chi P, Zou H, fusion cage was manufactured by using polymer melt differential three-dimensional
et al. Manufacturing and degrading (3D) printing technology. The study of the cage’s 3D structural characteristics on
features of 3D-printed porous spinal
interbody fusion cages. the degradation properties and the influence of the degradation process on its
Int J Bioprint. 2024;10(4):1996. mechanical properties was carried out. Preliminary cell viability assays were also
doi: 10.36922/ijb.1996 conducted. This study showed that the compressive strength of the cages increases
Received: October 9, 2023 with the aperture diameter and the number of crossing layers of the beams, and the
Accepted: February 5, 2024 compressive modulus is positively associated with the number of crossing layers of
Published Online: March 5, 2024 the beams. The degradation rate of the cage grew with the reduction of its filling rate
Copyright: © 2024 Author(s). and the rise of the number of crossing layers of the beams, i.e., the degradation rate
This is an Open Access article increased with the expansion of the internal aperture. The cage with a 60% internal
distributed under the terms of the
Creative Commons Attribution filling rate and containing 1 or 2 crossing layers of beams is more suited for spinal
License, permitting distribution, fusion, and with a pore size between 450 and 490 μm, the fundamental structure
and reproduction in any medium, of the cage can be preserved while maintaining strong support performance
provided the original work is
properly cited. throughout degradation. In addition, the 3D printing process in this study does not
cause an increase in cytotoxicity, making it a feasible bioprinting method.
Publisher’s Note: AccScience
Publishing remains neutral with
regard to jurisdictional claims in
published maps and institutional Keywords: Spinal interbody fusion cage; 3D printing; Meso-structure; Degradable;
affiliations. Polycaprolactone; Hydroxyapatite

Volume 10 Issue 4 (2024) 172 doi: 10.36922/ijb.1996