The micro-alloying effects of Y on the microstructure, mechanical properties, and bio-corrosion behavior of Mg69-xZn27Ca4Yx（x= 0, 1, 2 at.%） alloys were investigated through X-ray diffraction, compressive tests,elec...The micro-alloying effects of Y on the microstructure, mechanical properties, and bio-corrosion behavior of Mg69-xZn27Ca4Yx（x= 0, 1, 2 at.%） alloys were investigated through X-ray diffraction, compressive tests,electrochemical treatments, and immersion tests. The Mg69Zn27Ca4 alloy was found to be absolutely amorphous, and its glass-forming ability decreased with the addition of Y. The Mg68Zn27Ca4Y1 alloy exhibited an ultrahigh compressive strength above 1010 MPa as well as high capacity for plastic strain above 3.1%.Electrochemical and immersion tests revealed that these Y-doped MgeZ neC a alloys had good bio-corrosion resistance in simulated body fluid（SBF） at 37℃. The results of the cytotoxicity test showed high cell viabilities for these alloys, which means good bio-compatibility.展开更多
BACKGROUND： The oncogenesis of hepatocellular carcinoma（HCC） is not clear. The current methods of the pertinent studies are not precise and sensitive. The present study was to use liver cancer cell line to explore ...BACKGROUND： The oncogenesis of hepatocellular carcinoma（HCC） is not clear. The current methods of the pertinent studies are not precise and sensitive. The present study was to use liver cancer cell line to explore the bio-compatibility and cytotoxicity of ternary quantum dots（QDs） probe and to evaluate the possible application of QDs in HCC.METHODS： CuInS_2-ZnS-AFP fluorescence probe was designed and synthesized to label the liver cancer cell HepG 2. The cytotoxicity of CuInS_2-ZnS-AFP probe was evaluated by MTT experiments and flow cytometry. RESULTS： The labeling experiments indicated that CuInS_2-ZnS QDs conjugated with AFP antibody could enter HepG 2 cells effectively and emit intensive yellow fluorescence by ultraviolet excitation without changing cellular morphology. Toxicity tests suggested that the cytotoxicity of CuInS_2-ZnS-AFP probe was significantly lower than that of CdT e-ZnS-AFP probe（t test, F=0.8, T=-69.326, P〈0.001）. For CuInS_2-ZnS-AFP probe, timeeffect relationship was presented in intermediate concentration（〉20%） groups（P〈0.05） and dose-effect relationship was presented in almost all of the groups（P〈0.05）. CONCLUSION： CuInS_2-ZnS-AFP QDs probe had better biocompatibility and lower cytotoxicity compared with CdT e-ZnS-AFP probe, and could be used for imaging the living cells in vitro.展开更多
Bio-inspired porous metallic scaffolds have tremendous potential to be used as artificial bone substitutes.In this work,a radially graded lattice structure (RGLS),which mimics the structures of natural human bones,was...Bio-inspired porous metallic scaffolds have tremendous potential to be used as artificial bone substitutes.In this work,a radially graded lattice structure (RGLS),which mimics the structures of natural human bones,was designed and processed by laser powder bed fusion of martensitic Ti-rich TiNi powder.The asymmetric tension-compression behaviour,where the compressive strength is significantly higher than the tensile strength,is observed in this Ti-rich TiNi material,which echoes the mechanical behaviour of bones.The morphologies,mechanical properties,deformation behaviour,and biological compatibility of RGLS samples were characterised and compared with those in the uniform lattice structure.Both the uniform and RGLS samples achieve a relative density higher than 99%.The graded porosities and pore sizes in the RGLS range from 40%-80% and 330-805 µm,respectively,from the centre to the edge.The chemical etching has significantly removed the harmful partially-melted residual powder particles on the lattice struts.The compressive yield strength of RGLS is 71.5 MPa,much higher than that of the uniform sample (46.5 MPa),despite having a similar relative density of about 46%.The calculated Gibson-Ashby equation and the deformation behaviour simulation by finite element suggest that the dense outer regions with high load-bearing capability could sustain high applied stress,improving the overall strength of RGLS significantly.The cell proliferation study suggests better biological compatibility of the RGLS than the uniform structures.The findings highlight a novel strategy to improve the performance of additively manufactured artificial implants by bio-inspiration.展开更多
基金support of the National Natural Science Foundation of China (No. 51271206), Chinathe National Basic Research Program of China (No. 2013 CB632201), Chinathe Program for New Century Excellent Talents in University (No. NCET-11-0554), China
文摘The micro-alloying effects of Y on the microstructure, mechanical properties, and bio-corrosion behavior of Mg69-xZn27Ca4Yx（x= 0, 1, 2 at.%） alloys were investigated through X-ray diffraction, compressive tests,electrochemical treatments, and immersion tests. The Mg69Zn27Ca4 alloy was found to be absolutely amorphous, and its glass-forming ability decreased with the addition of Y. The Mg68Zn27Ca4Y1 alloy exhibited an ultrahigh compressive strength above 1010 MPa as well as high capacity for plastic strain above 3.1%.Electrochemical and immersion tests revealed that these Y-doped MgeZ neC a alloys had good bio-corrosion resistance in simulated body fluid（SBF） at 37℃. The results of the cytotoxicity test showed high cell viabilities for these alloys, which means good bio-compatibility.
基金supported by grants from the Nation al Natural Science Foundation of China(51272246 and 81172082)
文摘BACKGROUND： The oncogenesis of hepatocellular carcinoma（HCC） is not clear. The current methods of the pertinent studies are not precise and sensitive. The present study was to use liver cancer cell line to explore the bio-compatibility and cytotoxicity of ternary quantum dots（QDs） probe and to evaluate the possible application of QDs in HCC.METHODS： CuInS_2-ZnS-AFP fluorescence probe was designed and synthesized to label the liver cancer cell HepG 2. The cytotoxicity of CuInS_2-ZnS-AFP probe was evaluated by MTT experiments and flow cytometry. RESULTS： The labeling experiments indicated that CuInS_2-ZnS QDs conjugated with AFP antibody could enter HepG 2 cells effectively and emit intensive yellow fluorescence by ultraviolet excitation without changing cellular morphology. Toxicity tests suggested that the cytotoxicity of CuInS_2-ZnS-AFP probe was significantly lower than that of CdT e-ZnS-AFP probe（t test, F=0.8, T=-69.326, P〈0.001）. For CuInS_2-ZnS-AFP probe, timeeffect relationship was presented in intermediate concentration（〉20%） groups（P〈0.05） and dose-effect relationship was presented in almost all of the groups（P〈0.05）. CONCLUSION： CuInS_2-ZnS-AFP QDs probe had better biocompatibility and lower cytotoxicity compared with CdT e-ZnS-AFP probe, and could be used for imaging the living cells in vitro.
基金financially supported by the National Natural Science Foundation of China(52005189)Guangdong Basic and Applied Basic Research Foundation(2019A1515110542 and 2020A1515110699)+1 种基金Guangzhou Foreign Cooperation Projects(2020B1212060049 and 201704030067)Guangdong Academy of Sciences and the University of Birmingham(Contract 17-0551).
文摘Bio-inspired porous metallic scaffolds have tremendous potential to be used as artificial bone substitutes.In this work,a radially graded lattice structure (RGLS),which mimics the structures of natural human bones,was designed and processed by laser powder bed fusion of martensitic Ti-rich TiNi powder.The asymmetric tension-compression behaviour,where the compressive strength is significantly higher than the tensile strength,is observed in this Ti-rich TiNi material,which echoes the mechanical behaviour of bones.The morphologies,mechanical properties,deformation behaviour,and biological compatibility of RGLS samples were characterised and compared with those in the uniform lattice structure.Both the uniform and RGLS samples achieve a relative density higher than 99%.The graded porosities and pore sizes in the RGLS range from 40%-80% and 330-805 µm,respectively,from the centre to the edge.The chemical etching has significantly removed the harmful partially-melted residual powder particles on the lattice struts.The compressive yield strength of RGLS is 71.5 MPa,much higher than that of the uniform sample (46.5 MPa),despite having a similar relative density of about 46%.The calculated Gibson-Ashby equation and the deformation behaviour simulation by finite element suggest that the dense outer regions with high load-bearing capability could sustain high applied stress,improving the overall strength of RGLS significantly.The cell proliferation study suggests better biological compatibility of the RGLS than the uniform structures.The findings highlight a novel strategy to improve the performance of additively manufactured artificial implants by bio-inspiration.
