Extrusion-based additive manufacturing of Mg-Zn alloy scaffolds

Journal article (2022)

Authors

J. Dong Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
N. Tümer Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
M.A. Leeflang Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
P. Taheri Team Peyman Taheri - Mechanical, Maritime and Materials Engineering
E.L. Fratila-Apachitei Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
J.M.C. Mol Team Arjan Mol - Mechanical, Maritime and Materials Engineering
A.A. Zadpoor Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
J. Zhou Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering
Research Group
Biomaterials & Tissue Biomechanics (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2022 J. Dong, N. Tümer, M.A. Leeflang, P. Taheri, E.L. Fratila-Apachitei, J.M.C. Mol, A.A. Zadpoor, J. Zhou
DOI: https://doi.org/10.1016/j.jma.2021.11.018
More Info
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Published Date

2022

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Biomechanical Engineering

Research Group

Biomaterials & Tissue Biomechanics

Abstract

Porous biodegradable Mg and its alloys are considered to have a great potential to serve as ideal bone substitutes. The recent progress in additive manufacturing (AM) has prompted its application to fabricate Mg scaffolds with geometrically ordered porous structures. Extrusion-based AM, followed by debinding and sintering, has been recently demonstrated as a powerful approach to fabricating such Mg scaffolds, which can avoid some crucial problems encountered when applying powder bed fusion AM techniques. However, such pure Mg scaffolds exhibit a too high rate of in vitro biodegradation. In the present research, alloying through a pre-alloyed Mg-Zn powder was ultilized to enhance the corrosion resistance and mechanical properties of AM geometrically ordered Mg-Zn scaffolds simultaneously. The in vitro biodegradation behavior, mechanical properties, and electrochemical response of the fabricated Mg-Zn scaffolds were evaluated. Moreover, the response of preosteoblasts to these scaffolds was systematically evaluated and compared with their response to pure Mg scaffolds. The Mg-Zn scaffolds with a porosity of 50.3% and strut density of 93.1% were composed of the Mg matrix and MgZn2 second phase particles. The in vitro biodegradation rate of the Mg-Zn scaffolds decreased by 81% at day 1, as compared to pure Mg scaffolds. Over 28 days of static immersion in modified simulated body fluid, the corrosion rate of the Mg-Zn scaffolds decreased from 2.3 ± 0.9 mm/y to 0.7 ± 0.1 mm/y. The yield strength and Young's modulus of the Mg-Zn scaffolds were about 3 times as high as those of pure Mg scaffolds and remained within the range of those of trabecular bone throughout the biodegradation tests. Indirect culture of MC3T3-E1 preosteoblasts in Mg-Zn extracts indicated favorable cytocompatibility. In direct cell culture, some cells could spread and form filopodia on the surface of the Mg-Zn scaffolds. Overall, this study demonstrates the great potential of the extrusion-based AM Mg-Zn scaffolds to be further developed as biodegradable bone-substituting biomaterials.