The as-extruded Mg？Sn？Ca alloys were prepared and investigated for orthopedic applications via using optical microscopy, scanning electron microscopy, X-ray diffraction, as well as tensile, immersion and electrochem...The as-extruded Mg？Sn？Ca alloys were prepared and investigated for orthopedic applications via using optical microscopy, scanning electron microscopy, X-ray diffraction, as well as tensile, immersion and electrochemical tests. The results showed that, with the addition of 1% Sn and the Ca content of 0.2%？0.5%, the microstructure of the as-extruded Mg？Sn？Ca alloys became homogenous, which led to increased mechanical properties and improved corrosion resistance. Further increase of Ca content up to 1.5% improved the strength, but deteriorated the ductility and corrosion resistance. For the alloy containing 0.5% Ca, when the Sn content increased from 1% to 3%, the ultimate tensile strength increased with a decreased corrosion resistance, and the lowest yield strength and ductility appeared with the Sn content of 2%. These behaviors were determined by Sn/Ca mass ratio. The analyses showed that as-extruded Mg？1Sn？0.5Ca alloy was promising as a biodegradable orthopedic implant.展开更多
Long-segment defects remain a major problem in clinical treatment of tubular tissue reconstruction.The design of tubular scaffold with desired structure and functional properties suitable for tubular tissue regenerati...Long-segment defects remain a major problem in clinical treatment of tubular tissue reconstruction.The design of tubular scaffold with desired structure and functional properties suitable for tubular tissue regeneration remains a great challenge in regenerative medicine.Here,we present a reliable method to rapidly fabricate tissueengineered tubular scaffold with hierarchical structure via 4-axis printing system.The fabrication process can be adapted to various biomaterials including hydrogels,thermoplastic materials and thermosetting materials.Using polycaprolactone(PCL)as an example,we successfully fabricated the scaffolds with tunable tubular architecture,controllable mesh structure,radial elasticity,good flexibility,and luminal patency.As a preliminary demonstration of the applications of this technology,we prepared a hybrid tubular scaffold via the combination of the 4-axis printed elastic poly(glycerol sebacate)(PGS)bio-spring and electrospun gelatin nanofibers.The scaffolds seeded with chondrocytes formed tubular mature cartilage-like tissue both via in vitro culture and subcutaneous implantation in the nude mouse,which showed great potential for tracheal cartilage reconstruction.展开更多
基金Project(2013CB632200)supported by the National Basic Research Program of ChinaProjects(51474043,51531002)supported by the National Natural Science Foundation of China+1 种基金Projects(CSTC2013JCYJC60001,KJZH14101)supported by Chongqing Municipal Government,ChinaProject(2015M581350)supported by the China Postdoctoral Science Foundation
文摘The as-extruded Mg？Sn？Ca alloys were prepared and investigated for orthopedic applications via using optical microscopy, scanning electron microscopy, X-ray diffraction, as well as tensile, immersion and electrochemical tests. The results showed that, with the addition of 1% Sn and the Ca content of 0.2%？0.5%, the microstructure of the as-extruded Mg？Sn？Ca alloys became homogenous, which led to increased mechanical properties and improved corrosion resistance. Further increase of Ca content up to 1.5% improved the strength, but deteriorated the ductility and corrosion resistance. For the alloy containing 0.5% Ca, when the Sn content increased from 1% to 3%, the ultimate tensile strength increased with a decreased corrosion resistance, and the lowest yield strength and ductility appeared with the Sn content of 2%. These behaviors were determined by Sn/Ca mass ratio. The analyses showed that as-extruded Mg？1Sn？0.5Ca alloy was promising as a biodegradable orthopedic implant.
基金supported by the National Key Research and Development Program of China (2018YFB1105602 and 2017YFC1103900)the National Natural Science Foundation of China (21574019, 81320108010, 81571823 and 81871502)+4 种基金the Natural Science Foundation of Shanghai (18ZR1401900)the Fundamental Research Funds for the Central Universities, DHU Distinguished Young Professor Program (LZA2019001)the Science and Technology Commission of Shanghai (17DZ2260100 and 15DZ1941600)the Program for Shanghai Outstanding Medical Academic Leaderthe Program of Shanghai Technology Research Leader
文摘Long-segment defects remain a major problem in clinical treatment of tubular tissue reconstruction.The design of tubular scaffold with desired structure and functional properties suitable for tubular tissue regeneration remains a great challenge in regenerative medicine.Here,we present a reliable method to rapidly fabricate tissueengineered tubular scaffold with hierarchical structure via 4-axis printing system.The fabrication process can be adapted to various biomaterials including hydrogels,thermoplastic materials and thermosetting materials.Using polycaprolactone(PCL)as an example,we successfully fabricated the scaffolds with tunable tubular architecture,controllable mesh structure,radial elasticity,good flexibility,and luminal patency.As a preliminary demonstration of the applications of this technology,we prepared a hybrid tubular scaffold via the combination of the 4-axis printed elastic poly(glycerol sebacate)(PGS)bio-spring and electrospun gelatin nanofibers.The scaffolds seeded with chondrocytes formed tubular mature cartilage-like tissue both via in vitro culture and subcutaneous implantation in the nude mouse,which showed great potential for tracheal cartilage reconstruction.
