Title
Additively manufactured biodegradable porous magnesium
Author
Li, Y. (TU Delft Biomaterials & Tissue Biomechanics) 
Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)
Pavanram, P. (Medizinische Fakultat und Universitats Klinikum Aachen)
Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics)
Fockaert, L.I. (TU Delft (OLD) MSE-6)
Pouran, B. (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht)
Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics)
Schröder, K. U. (Institut für Maschinengestaltung und Maschinenelemente)
Mol, J.M.C. (TU Delft (OLD) MSE-6)
Weinans, Harrie (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht)
Jahr, H. (Medizinische Fakultat und Universitats Klinikum Aachen; Maastricht UMC)
Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)
Date
2017
Abstract
An ideal bone substituting material should be bone-mimicking in terms of mechanical properties, present a precisely controlled and fully interconnected porous structure, and degrade in the human body to allow for full regeneration of large bony defects. However, simultaneously satisfying all these three requirements has so far been highly challenging. Here we present topologically ordered porous magnesium (WE43) scaffolds based on the diamond unit cell that were fabricated by selective laser melting (SLM) and satisfy all the requirements. We studied the in vitro biodegradation behavior (up to 4 weeks), mechanical properties and biocompatibility of the developed scaffolds. The mechanical properties of the AM porous WE43 (E = 700-800 MPa) scaffolds were found to fall into the range of the values reported for trabecular bone even after 4 weeks of biodegradation. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), electrochemical tests and μCT revealed a unique biodegradation mechanism that started with uniform corrosion, followed by localized corrosion, particularly in the center of the scaffolds. Biocompatibility tests performed up to 72 h showed level 0 cytotoxicity (according to ISO 10993-5 and -12), except for one time point (i.e., 24 h). Intimate contact between cells (MG-63) and the scaffolds was also observed in SEM images. The study shows for the first time that AM of porous Mg may provide distinct possibilities to adjust biodegradation profile through topological design and open up unprecedented opportunities to develop multifunctional bone substituting materials that mimic bone properties and enable full regeneration of critical-size load-bearing bony defects. Statement of Significance: The ideal biomaterials for bone tissue regeneration should be bone-mimicking in terms of mechanical properties, present a fully interconnected porous structure, and exhibit a specific biodegradation behavior to enable full regeneration of bony defects. Recent advances in additive manufacturing have resulted in biomaterials that satisfy the first two requirements but simultaneously satisfying the third requirement has proven challenging so far. Here we present additively manufactured porous magnesium structures that have the potential to satisfy all above-mentioned requirements. Even after 4 weeks of biodegradation, the mechanical properties of the porous structures were found to be within those reported for native bone. Moreover, our comprehensive electrochemical, mechanical, topological, and biological study revealed a unique biodegradation behavior and the limited cytotoxicity of the developed biomaterials.
Subject
Additive manufacturing
Biocompatibility
Biodegradation
Magnesium scaffolds
Mechanical property
Selective laser melting
To reference this document use:
http://resolver.tudelft.nl/uuid:b5e6e3ed-a25e-4072-b732-98d7cd17b258
DOI
https://doi.org/10.1016/j.actbio.2017.12.008
Embargo date
2018-06-12
ISSN
1742-7061
Source
Acta Biomaterialia, 67 ( Febr. 2018), 378-392
Bibliographical note
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2017 Y. Li, J. Zhou, P. Pavanram, M.A. Leeflang, L.I. Fockaert, B. Pouran, N. Tümer, K. U. Schröder, J.M.C. Mol, Harrie Weinans, H. Jahr, A.A. Zadpoor