Fatigue and quasi-static mechanical behavior of bio-degradable porous biomaterials based on magnesium alloys

Fatigue and quasi-static mechanical behavior of bio-degradable porous biomaterials based on magnesium alloys

Hedayati, R. (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht)
Ahmadi, S.M. (TU Delft (OLD) MSE-5)
Lietaert, K. (3D Systems – LayerWise NV; Katholieke Universiteit Leuven)
Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics)
Li, Y (TU Delft BT/Biocatalysis)
Amin Yavari, S. (University Medical Center Utrecht)
Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)

2018

Magnesium and its alloys have the intrinsic capability of degrading over time in vivo without leaving toxic degradation products. They are therefore suitable for use as biodegradable scaffolds that are replaced by the regenerated tissues. One of the main concerns for such applications, particularly in load-bearing areas, is the sufficient mechanical integrity of the scaffold before sufficient volumes of de novo tissue is generated. In the majority of the previous studies on the effects of biodegradation on the mechanical properties of porous biomaterials, the change in the elastic modulus has been studied. In this study, variations in the static and fatigue mechanical behavior of porous structures made of two different Mg alloys (AZ63 and M2) over different dissolution times ( 6, 12, and 24 h) have been investigated. The results showed an increase in the mechanical properties obtained from stress-strain curve (elastic modulus, yield stress, plateau stress, and energy absorption) after 6-12 h and a sharp decrease after 24 h. The initial increase in the mechanical properties may be attributed to the accumulation of corrosion products in the pores of the porous structure before degradation has considerably proceeded. The effects of mineral deposition was more pronounced for the elastic modulus as compared to other mechanical properties. That may be due to insufficient integration of the deposited particles in the structure of the magnesium alloys. While the bonding of the parts being combined in a composite-like material is of great importance in determining its yield stress, the effects of bonding strength of both parts is much lower in determining the elastic modulus. The results of the current study also showed that the dissolution rates of the studied Mg alloys were too high for direct use in human body.

Biodegradation
Fatigue
Magnesium alloy
Mechanical properties
Porous biomaterials

http://resolver.tudelft.nl/uuid:915b1d07-1108-4c39-8e1b-31ae10ba6c8c

https://doi.org/10.1002/jbm.a.36380

1549-3296

Journal of Biomedical Materials Research. Part A, 106 (7), 1798-1811

Institutional Repository

journal article

© 2018 R. Hedayati, S.M. Ahmadi, K. Lietaert, N. Tümer, Y Li, S. Amin Yavari, A.A. Zadpoor