The present study investigates Mg-SiO2 nanocomposites as biodegradable implants for orthopedic and maxillofacial applications.The effect of presence and progressive addition of hollow silica nanoparticles(0.5,1,and 1....The present study investigates Mg-SiO2 nanocomposites as biodegradable implants for orthopedic and maxillofacial applications.The effect of presence and progressive addition of hollow silica nanoparticles(0.5,1,and 1.5)vol.%on the microstructural,mechanical,degradation,and biocompatibility response of pure Mg were investigated.Results suggest that the increased addition of hollow silica nanoparticles resulted in a progressive increase in yield strength and ultimate compressive strength with Mg-1.5 vol.%SiO2 exhibiting superior enhancement.The response of Mg-SiO2 nanocomposites under the influence of Hanks’balanced salt solution revealed that the synthesized composites revealed lower corrosion rates,indicating rapid dynamic passivation when compared with pure Mg.Furthermore,cell adhesion and proliferation of osteoblast cells were noticeably higher than pure Mg with the addition of 1 vol.%SiO2 nanoparticle.The biocompatibility and the in vitro biodegradation of the Mg-SiO2 nanocomposites were influenced by the SiO2 content in pure Mg with Mg-0.5 vol.%SiO2 nanocomposite exhibiting the best corrosion resistance and biocompatibility when compared with other nanocomposites.Enhancement in mechanical,corrosion,and biocompatibility characteristics of Mg-SiO2 nanocomposites developed in this study are also compared with properties of other metallic biomaterials used in alloplastic mandibular reconstruction in a computational model.展开更多
Near dense Mg 0.5 wt.% Zr（0,1,2.5 and 4） wt.% La alloys were successfully synthesized by disintegrated melt deposition technique followed by hot extrusion and were characterized for their microstructural, ignition, ...Near dense Mg 0.5 wt.% Zr（0,1,2.5 and 4） wt.% La alloys were successfully synthesized by disintegrated melt deposition technique followed by hot extrusion and were characterized for their microstructural, ignition, hardness, tensile and compression properties. Combined effects of Zr and La assisted in significant grain refinement of Mg and Mg 0.5 wt.% Zr 4 wt.% La exhibited an average grain size as low as ~2.75 μm. High ignition temperature of ~645 oC was realized with Mg 0.5 wt.% Zr（1,2.5 and 4） wt.% La alloys. Microhardness value as high as ~103 Hv was observed with Mg 0.5 wt.% Zr 4 wt.% La alloy. Under room temperature tensile and compression loading, significant improvements in the strength properties of pure Mg with the addition of 0.5 wt.% Zr（0, 1, 2.5 and 4） wt.% La was observed. Mg 0.5 wt.% Zr 4 wt.% La exhibited the maximum 0.2% tensile and compression yield strengths of ~283 MPa and ~264 MPa, respectively. The tensile and compression fracture strain values of synthesized pure Mg were found to be unaffected with the addition of 0.5 wt.% Zr. But the tensile fracture strain reduced with the addition of La while the compressive fracture strain was unaffected. Minimal tensile-compression asymmetry（~1） was exhibited by Mg 0.5 wt.% Zr（1 and 2.5） wt.% La alloys.展开更多
基金This work was supported by the Singapore Ministry of Education Academic Research Funding grant number WBS#R-265-000-684-114.
文摘The present study investigates Mg-SiO2 nanocomposites as biodegradable implants for orthopedic and maxillofacial applications.The effect of presence and progressive addition of hollow silica nanoparticles(0.5,1,and 1.5)vol.%on the microstructural,mechanical,degradation,and biocompatibility response of pure Mg were investigated.Results suggest that the increased addition of hollow silica nanoparticles resulted in a progressive increase in yield strength and ultimate compressive strength with Mg-1.5 vol.%SiO2 exhibiting superior enhancement.The response of Mg-SiO2 nanocomposites under the influence of Hanks’balanced salt solution revealed that the synthesized composites revealed lower corrosion rates,indicating rapid dynamic passivation when compared with pure Mg.Furthermore,cell adhesion and proliferation of osteoblast cells were noticeably higher than pure Mg with the addition of 1 vol.%SiO2 nanoparticle.The biocompatibility and the in vitro biodegradation of the Mg-SiO2 nanocomposites were influenced by the SiO2 content in pure Mg with Mg-0.5 vol.%SiO2 nanocomposite exhibiting the best corrosion resistance and biocompatibility when compared with other nanocomposites.Enhancement in mechanical,corrosion,and biocompatibility characteristics of Mg-SiO2 nanocomposites developed in this study are also compared with properties of other metallic biomaterials used in alloplastic mandibular reconstruction in a computational model.
基金Project supported by Singapore Ministry of Education Academic Research Fund Tier 2(R265000498112)
文摘Near dense Mg 0.5 wt.% Zr（0,1,2.5 and 4） wt.% La alloys were successfully synthesized by disintegrated melt deposition technique followed by hot extrusion and were characterized for their microstructural, ignition, hardness, tensile and compression properties. Combined effects of Zr and La assisted in significant grain refinement of Mg and Mg 0.5 wt.% Zr 4 wt.% La exhibited an average grain size as low as ~2.75 μm. High ignition temperature of ~645 oC was realized with Mg 0.5 wt.% Zr（1,2.5 and 4） wt.% La alloys. Microhardness value as high as ~103 Hv was observed with Mg 0.5 wt.% Zr 4 wt.% La alloy. Under room temperature tensile and compression loading, significant improvements in the strength properties of pure Mg with the addition of 0.5 wt.% Zr（0, 1, 2.5 and 4） wt.% La was observed. Mg 0.5 wt.% Zr 4 wt.% La exhibited the maximum 0.2% tensile and compression yield strengths of ~283 MPa and ~264 MPa, respectively. The tensile and compression fracture strain values of synthesized pure Mg were found to be unaffected with the addition of 0.5 wt.% Zr. But the tensile fracture strain reduced with the addition of La while the compressive fracture strain was unaffected. Minimal tensile-compression asymmetry（~1） was exhibited by Mg 0.5 wt.% Zr（1 and 2.5） wt.% La alloys.
