Additively manufactured functionally graded biodegradable porous zinc

Journal article (2020)

Authors

Y. Li Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
P. Pavanram University Hospital RWTH Aachen
J. Zhou Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Karel Lietaert Katholieke Universiteit Leuven, 3D Systems – LayerWise NV
F.S.L. Bobbert Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Yusuke Kubo University Hospital RWTH Aachen
M.A. Leeflang Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Sander A. Leeflang Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
H. Jahr University Hospital RWTH Aachen, Maastricht University Medical Center
A. A. Zadpoor Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
A.A. Zadpoor Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Amir A. Zadpoor Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Amir Abbas Zadpoor Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Research Group
Biomaterials & Tissue Biomechanics (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2020 Y. Li, P. Pavanram, J. Zhou, K. Lietaert, F.S.L. Bobbert, Yusuke Kubo, M.A. Leeflang, H. Jahr, A.A. Zadpoor
DOI: https://doi.org/10.1039/c9bm01904a
More Info
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Published Date

2020

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Biomechanical Engineering

Research Group

Biomaterials & Tissue Biomechanics

Abstract

Topological design provides additively manufactured (AM) biodegradable porous metallic biomaterials with a unique opportunity to adjust their biodegradation behavior and mechanical properties, thereby satisfying the requirements for ideal bone substitutes. However, no information is available yet concerning the effect of topological design on the performance of AM porous zinc (Zn) that outperforms Mg and Fe in biodegradation behavior. Here, we studied one functionally graded and two uniform AM porous Zn designs with diamond unit cell. Cylindrical specimens were fabricated from pure Zn powder by using a powder bed fusion technique, followed by a comprehensive study on their static and dynamic biodegradation behaviors, mechanical properties, permeability, and biocompatibility. Topological design, indeed, affected the biodegradation behavior of the specimens, as evidenced by 150% variations in biodegradation rate between the three different designs. After in vitro dynamic immersion for 28 days, the AM porous Zn had weight losses of 7-12%, relying on the topological design. The degradation rates satisfied the desired biodegradation time of 1-2 years for bone substitution. The mechanical properties of the biodegraded specimens of all the groups maintained within the range of those of cancellous bone. As opposed to the trends observed for other biodegradable porous metals, after 28 days of in vitro biodegradation, the yield strengths of the specimens of all the groups (σy = 7-14 MPa) increased consistently, as compared to those of the as-built specimens (σy = 4-11 MPa). Moreover, AM porous Zn showed excellent biocompatibility, given that the cellular activities in none of the groups differed from the Ti controls for up to 72 h. Using topological design of AM porous Zn for controlling its mechanical properties and degradation behavior is thus clearly promising, thereby rendering flexibility to the material to meet a variety of clinical requirements.