Title
Extrusion-based 3D printing of biodegradable, osteogenic, paramagnetic, and porous FeMn-akermanite bone substitutes
Author
Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics) 
Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics)
Klimopoulou, M. (TU Delft Biomaterials & Tissue Biomechanics)
Dong, J. (TU Delft Biomaterials & Tissue Biomechanics)
Taheri, P. (TU Delft Team Peyman Taheri)
Huan, Z. (Shanghai Institute of Ceramics Chinese Academy of Sciences)
Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics)
Mol, J.M.C. (TU Delft Team Arjan Mol)
Chang, J. (Shanghai Institute of Ceramics Chinese Academy of Sciences)
Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)
Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)
Date
2023
Abstract
The development of biodegradable Fe-based bone implants has rapidly progressed in recent years. Most of the challenges encountered in developing such implants have been tackled individually or in combination using additive manufacturing technologies. Yet not all the challenges have been overcome. Herein, we present porous FeMn-akermanite composite scaffolds fabricated by extrusion-based 3D printing to address the unmet clinical needs associated with Fe-based biomaterials for bone regeneration, including low biodegradation rate, MRI-incompatibility, mechanical properties, and limited bioactivity. In this research, we developed inks containing Fe, 35 wt% Mn, and 20 or 30 vol% akermanite powder mixtures. 3D printing was optimized together with the debinding and sintering steps to obtain scaffolds with interconnected porosity of 69%. The Fe-matrix in the composites contained the γ-FeMn phase as well as nesosilicate phases. The former made the composites paramagnetic and, thus, MRI-friendly. The in vitro biodegradation rates of the composites with 20 and 30 vol% akermanite were respectively 0.24 and 0.27 mm/y, falling within the ideal range of biodegradation rates for bone substitution. The yield strengths of the porous composites stayed within the range of the values of the trabecular bone, despite in vitro biodegradation for 28 d. All the composite scaffolds favored the adhesion, proliferation, and osteogenic differentiation of preosteoblasts, as revealed by Runx2 assay. Moreover, osteopontin was detected in the extracellular matrix of cells on the scaffolds. Altogether, these results demonstrate the remarkable potential of these composites in fulfilling the requirements of porous biodegradable bone substitutes, motivating future in vivo research. Statement of significance: We developed FeMn-akermanite composite scaffolds by taking advantage of the multi-material capacity of extrusion-based 3D printing. Our results demonstrated that the FeMn-akermanite scaffolds showed an exceptional performance in fulfilling all the requirements for bone substitution in vitro, i.e., a sufficient biodegradation rate, having mechanical properties in the range of trabecular bone even after 4 weeks biodegradation, paramagnetic, cytocompatible and most importantly osteogenic. Our results encourage further research on Fe-based bone implants in in vivo.
Subject
Akermanite
Biodegradable
Bone
Extrusion-based 3D printing
Iron-manganese
Scaffold
To reference this document use:
http://resolver.tudelft.nl/uuid:617375c2-27ed-429d-bb8c-a0ffef28e042
DOI
https://doi.org/10.1016/j.actbio.2023.03.033
ISSN
1742-7061
Source
Acta Biomaterialia, 162, 182-198
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2023 N.E. Putra, M.A. Leeflang, M. Klimopoulou, J. Dong, P. Taheri, Z. Huan, E.L. Fratila-Apachitei, J.M.C. Mol, J. Chang, J. Zhou, A.A. Zadpoor