The Experts below are selected from a list of 13569 Experts worldwide ranked by ideXlab platform
Prashant N Kumta - One of the best experts on this subject based on the ideXlab platform.
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are the low ductility and ...
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are their low ductility and fast corrosion rates. Several studies have validated that introduction of Li into the magnesium alloys will significantly improve the ductility while alloying with Al will improve the corrosion resistance and strength. In the present study, we studied the effects of alloying different amounts of Li and Al on the Mg-Li-Al-Zn (LAZ) quaternary alloy system. Rods were made from four different LAZ alloys, namely, LAZ611, LAZ631, LAZ911, and LAZ931 following melting, casting, and then extrusion. Systematic assessment of mechanical properties, in vitro corrosion, cytotoxicity, and in vivo degradation including local and systemic toxicity conducted demonstrated the beneficial effects of Li and Al on the mechanical properties. Our results specifically suggest that alloying with Li significantly improved the ductility while Al enhanced the strength of the LAZ alloys. Four of the LAZ alloys exhibited different corrosion rates in Hank's balanced salt solution depending on the chemical composition. Indirect in vitro cytotoxicity tests also showed lower cytotoxicity for the alloys exhibiting higher corrosion resistance. In vivo corrosion rates in the mouse subcutaneous model showed different corrosion rates compared to the in vitro tests. Nevertheless, all of the four LAZ alloys displayed no local and systemic toxicity based on the histology analysis. This research study, therefore, demonstrated the benefits of using Li and Al as alloying elements in LAZ alloys and the potential use of LAZ alloys for Vascular Stent application.
Daoli Zhao - One of the best experts on this subject based on the ideXlab platform.
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are the low ductility and ...
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are their low ductility and fast corrosion rates. Several studies have validated that introduction of Li into the magnesium alloys will significantly improve the ductility while alloying with Al will improve the corrosion resistance and strength. In the present study, we studied the effects of alloying different amounts of Li and Al on the Mg-Li-Al-Zn (LAZ) quaternary alloy system. Rods were made from four different LAZ alloys, namely, LAZ611, LAZ631, LAZ911, and LAZ931 following melting, casting, and then extrusion. Systematic assessment of mechanical properties, in vitro corrosion, cytotoxicity, and in vivo degradation including local and systemic toxicity conducted demonstrated the beneficial effects of Li and Al on the mechanical properties. Our results specifically suggest that alloying with Li significantly improved the ductility while Al enhanced the strength of the LAZ alloys. Four of the LAZ alloys exhibited different corrosion rates in Hank's balanced salt solution depending on the chemical composition. Indirect in vitro cytotoxicity tests also showed lower cytotoxicity for the alloys exhibiting higher corrosion resistance. In vivo corrosion rates in the mouse subcutaneous model showed different corrosion rates compared to the in vitro tests. Nevertheless, all of the four LAZ alloys displayed no local and systemic toxicity based on the histology analysis. This research study, therefore, demonstrated the benefits of using Li and Al as alloying elements in LAZ alloys and the potential use of LAZ alloys for Vascular Stent application.
Shaokang Guan - One of the best experts on this subject based on the ideXlab platform.
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multifunctional mgf2 polydopamine coating on mg alloy for Vascular Stent application
Journal of Materials Science & Technology, 2015Co-Authors: Xiaoli Liu, Shaokang Guan, Jing Liu, Yufeng Zheng, Zhen Zhen, Yudong Zheng, Yan ChengAbstract:Mg alloy is of great potential in the application of Vascular Stent due to its degradation in physical environment and proper mechanical property. However its mechanical integrity does not meet the clinical requirement due to relatively fast degradation. Besides, in order to accelerate the re-endothelialization of Mg-based Stents, it needs surface modification to improve the attachment, growth and adhesion of endothelial cells (ECs). To solve the main obstacles, an anti-corrosion and quick endothelialization coating was prepared on novel Mg–Zn–Y‒Nd alloy via a simple two-step immersion method in the present study, first in hydrofluoric acid (HF) then in dopamine tris–Hydrochloric acid (tris–HCl) solution. The coating was uniform and thin, which consisted of two layers—the upper was polydopamine (PDA) layer and the lower was MgF2 layer. The alloy with the coating demonstrated dramatic corrosion resistance enhancement in vitro by immersion test and electrochemical test. Moreover the HF-PDA-treated Mg alloy exhibited great performance of cell adhesion and proliferation. The coating created a favorable environment for ECs to have a competitive advantage over Vascular smooth muscle cells (VSMCs), which was preferable for re-endothelialization. The results suggest that HF-PDA-treated Mg–Zn–Y‒Nd alloy has great potential in the application of Vascular Stent and the surface coating method is of great application value in biodegradable Mg alloy Stent due to its simplicity and effectiveness.
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the microstructure and properties of cyclic extrusion compression treated mg zn y nd alloy for Vascular Stent application
Journal of The Mechanical Behavior of Biomedical Materials, 2012Co-Authors: Shijie Zhu, Liguo Wang, Qian Liu, Gaochao Yue, Shaokang GuanAbstract:Abstract Magnesium alloys are promising candidate materials for cardioVascular Stents due to their good biocompatibility and degradation properties in the human body. However, in vivo tests also show that improvement in their mechanical properties and corrosion resistance is necessary before wide application. In this study, cyclic extrusion compression (CEC) was used to enhance the mechanical properties and corrosion resistance of Mg–Zn–Y–Nd alloy. The results show that the grain size was greatly refined to 1 μ m after CEC treatment. The second phase distributed along the grain boundaries with grid shape and nano-sized particles uniformly distributed in grains. The elongation ( δ ), ultimate tensile strength (UTS) and yield strength (YS) of the CEC treatment samples were 30.2%, 303 MPa and 185 MPa respectively. The CEC treated samples showed homogeneous corrosion because of the grain refinement and the homogeneous distribution of nano-sized second phase. The corrosion current density of the alloy decreased from 2.8 × 10 − 4 A/cm 2 to 6.6 × 10 − 5 A/cm 2 after CEC treatment. Therefore, improved mechanical properties, uniform corrosion and reduced corrosion rate could be achieved by CEC.
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microstructure and corrosion properties of as sub rapid solidification mg zn y nd alloy in dynamic simulated body fluid for Vascular Stent application
Journal of Materials Science: Materials in Medicine, 2010Co-Authors: Liguo Wang, Shaokang GuanAbstract:Magnesium alloy Stent has been employed in animal and clinical experiment in recent years. It has been verified to be biocompatible and degradable due to corrosion after being implanted into blood vessel. Mg–Y–Gd–Nd alloy is usually used to construct an absorbable magnesium alloy Stent. However, the corrosion resistant of as cast Mg–Y–Gd–Nd alloy is poor relatively and the control of corrosion rate is difficult. Aiming at the requirement of endoVascular Stent in clinic, a new biomedical Mg–Zn–Y–Nd alloy with low Zn and Y content (Zn/Y atom ratio 6) was designed, which exists quasicrystals to improve its corrosion resistance. Additionally, sub-rapid solidification processing was applied for preparation of corrosion-resisting Mg–Zn–Y–Nd and Mg–Y–Gd–Nd alloys. Compared with the as cast sample, the corrosion behavior of alloys in dynamic simulated body fluid (SBF) (the speed of body fluid: 16 ml/800 ml min−1) was investigated. The results show that as sub-rapid solidification Mg–Zn–Y–Nd alloy has the better corrosion resistance in dynamic SBF due to grain refinement and fine dispersion distribution of the quasicrystals and intermetallic compounds in α-Mg matrix. In the as cast sample, both Mg–Zn–Y–Nd and Mg–Y–Gd–Nd alloys exhibit poor corrosion resistance. Mg–Zn–Y–Nd alloy by sub-rapid solidification processing provides excellent corrosion resistance in dynamic SBF, which open a new window for biomedical materials design, especially for Vascular Stent application.
William R Heineman - One of the best experts on this subject based on the ideXlab platform.
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are the low ductility and ...
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are their low ductility and fast corrosion rates. Several studies have validated that introduction of Li into the magnesium alloys will significantly improve the ductility while alloying with Al will improve the corrosion resistance and strength. In the present study, we studied the effects of alloying different amounts of Li and Al on the Mg-Li-Al-Zn (LAZ) quaternary alloy system. Rods were made from four different LAZ alloys, namely, LAZ611, LAZ631, LAZ911, and LAZ931 following melting, casting, and then extrusion. Systematic assessment of mechanical properties, in vitro corrosion, cytotoxicity, and in vivo degradation including local and systemic toxicity conducted demonstrated the beneficial effects of Li and Al on the mechanical properties. Our results specifically suggest that alloying with Li significantly improved the ductility while Al enhanced the strength of the LAZ alloys. Four of the LAZ alloys exhibited different corrosion rates in Hank's balanced salt solution depending on the chemical composition. Indirect in vitro cytotoxicity tests also showed lower cytotoxicity for the alloys exhibiting higher corrosion resistance. In vivo corrosion rates in the mouse subcutaneous model showed different corrosion rates compared to the in vitro tests. Nevertheless, all of the four LAZ alloys displayed no local and systemic toxicity based on the histology analysis. This research study, therefore, demonstrated the benefits of using Li and Al as alloying elements in LAZ alloys and the potential use of LAZ alloys for Vascular Stent application.
Zhongyun Dong - One of the best experts on this subject based on the ideXlab platform.
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are the low ductility and ...
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effect of lithium and aluminum on the mechanical properties in vivo and in vitro degradation and toxicity of multiphase ultrahigh ductility mg li al zn quaternary alloys for Vascular Stent application
ACS Biomaterials Science & Engineering, 2020Co-Authors: Daoli Zhao, Boeun Lee, Abhijit Roy, Raymon Yao, Shauna Chen, Zhongyun Dong, William R Heineman, Prashant N KumtaAbstract:Magnesium alloys are the most widely studied biodegradable metals for biodegradable Vascular Stent application. Two major issues with current magnesium alloy based Stents are their low ductility and fast corrosion rates. Several studies have validated that introduction of Li into the magnesium alloys will significantly improve the ductility while alloying with Al will improve the corrosion resistance and strength. In the present study, we studied the effects of alloying different amounts of Li and Al on the Mg-Li-Al-Zn (LAZ) quaternary alloy system. Rods were made from four different LAZ alloys, namely, LAZ611, LAZ631, LAZ911, and LAZ931 following melting, casting, and then extrusion. Systematic assessment of mechanical properties, in vitro corrosion, cytotoxicity, and in vivo degradation including local and systemic toxicity conducted demonstrated the beneficial effects of Li and Al on the mechanical properties. Our results specifically suggest that alloying with Li significantly improved the ductility while Al enhanced the strength of the LAZ alloys. Four of the LAZ alloys exhibited different corrosion rates in Hank's balanced salt solution depending on the chemical composition. Indirect in vitro cytotoxicity tests also showed lower cytotoxicity for the alloys exhibiting higher corrosion resistance. In vivo corrosion rates in the mouse subcutaneous model showed different corrosion rates compared to the in vitro tests. Nevertheless, all of the four LAZ alloys displayed no local and systemic toxicity based on the histology analysis. This research study, therefore, demonstrated the benefits of using Li and Al as alloying elements in LAZ alloys and the potential use of LAZ alloys for Vascular Stent application.
