After reconstructing the anterior cruciate ligament(ACL),unsatisfactory bone tendon interface healing may often induce tunnel enlargement at the early healing stage.With good biological features and high formability,M...After reconstructing the anterior cruciate ligament(ACL),unsatisfactory bone tendon interface healing may often induce tunnel enlargement at the early healing stage.With good biological features and high formability,Magnesium-Zinc-Gadolinium(ZG21)wires are developed to bunch the tendon graft for matching the bone tunnel during transplantation.Microstructure,tensile strength,degradation,and cytotoxicity of ZG21 wire are evaluated.The rabbit model is used for assessing the biological effects of ZG21 wire by Micro-CT,histology,and mechanical test.The SEM/EDS,immunochemistry,and in vitro assessments are performed to investigate the underlying mechanism.Material tests demonstrate the high formability of ZG21 wire as surgical suture.Micro-CT shows ZG21 wire degradation accelerates tunnel bone formation,and histologically with earlier and more fibrocartilage regeneration at the healing interface.The mechanical test shows higher ultimate load in the ZG21 group.The SEM/EDS presents ZG21 wire degradation triggered calcium phosphate(Ca-P)deposition.IHC results demonstrate upregulation of Wnt3a,BMP2,and VEGF at the early phase and TGFβ3 and Type II collagen at the late phase of healing.In vitro tests also confirmed the Ca-P in the metal extract could elevate the expression of Wnt3a,βcatenin,ocn and opn to stimulate osteogenesis.Ex vivo tests of clinical samples indicated suturing with ZG21 wire did not weaken the ultimate loading of human tendon tissue.In conclusion,the ZG21 wire is feasible for tendon graft bunching.Its degradation products accelerated intra-tunnel endochondral ossification at the early healing stage and therefore enhanced bone-tendon interface healing in ACL reconstruction.展开更多
To develop a biodegradable membrane with guided bone regeneration(GBR),a Mg-2.0Zn-1.0Gd alloy(wt.%,MZG)membrane with Ca-P coating was designed and fabricated in this study.The microstructure,hydrophilicity,in vitro de...To develop a biodegradable membrane with guided bone regeneration(GBR),a Mg-2.0Zn-1.0Gd alloy(wt.%,MZG)membrane with Ca-P coating was designed and fabricated in this study.The microstructure,hydrophilicity,in vitro degradation,cytotoxicity,antibacterial effect and in vivo regenerative performance for the membrane with and without Ca-P coating were evaluated.After coating,the membrane exhibited an enhance hydrophilicity and corrosion resistance,showed good in vitro cytocompatibility upon MC3T3E-1 cells,and exhibited excellent antibacterial effect against E.coli,Staphylococcus epidermis and Staphylococcus aureus,simultaneously.In vivo experiment using the rabbit calvarial defect model confirmed that Ca-P coated MZG membrane underwent progressive degradation without inflammatory reaction and significantly improved the new bone formation at both 1.5 and 3 months after the surgery.All the results strongly indicate that MZG with Ca-P coating have great potential for clinical application as GBR membranes.展开更多
We prepare a new type of patented biodegradable biomedical Mg-Nd-Zn-Zr(JDBM)alloy system and impose double continuously extrusion(DCE)processing.The lowest processing temperature is 250℃for JDBM-2.1Nd and 310℃for JD...We prepare a new type of patented biodegradable biomedical Mg-Nd-Zn-Zr(JDBM)alloy system and impose double continuously extrusion(DCE)processing.The lowest processing temperature is 250℃for JDBM-2.1Nd and 310℃for JDBM-2.8Nd,which increases with the Nd concentration.The highest yield strength of 541 MPa is achieved in JDBM-2.1 Nd samples when extruded at 250℃and the elongation is about 3.7%.Moreover,the alloy with a lower alloying element content can reach a higher yield strength while that with a higher alloying element content can reach a larger elongation after DCE processing.However,when extruded under the same conditions,the alloy with a higher alloying contents exhibits better tensile properties.展开更多
2D transition metal dichalcogenides(TMDs)have been considered as promising non-precious electrocatalysts for the hydrogen evolution reaction(HER).However,their limited active sites and poor electric conductivity pose ...2D transition metal dichalcogenides(TMDs)have been considered as promising non-precious electrocatalysts for the hydrogen evolution reaction(HER).However,their limited active sites and poor electric conductivity pose a significant hurdle to their HER performance,resulting in a large overpotential.Here,we report the defect engineering in ultrathin tungsten telluride(WTe_(2))nanosheets with semimetal nature to improve hydrogen evolution effectively.We find that the oxygen plasma etching imposes a cutting effect on WTe_(2)nanosheets,resulting in a large number of tungsten vacancies.Particularly,the sample after plasma treatment for 10 min shows a feather-like structure with an overpotential of 251m V at 10 m A/cm~2and a Tafel slope of 94 m V/dec,which is 4 times lower than the Tafel slope of pristine nanosheets.Further first-principles calculations shed light on the evolution of defect-rich WTe_(2)nanosheets and offer rational explanation to their superiority in efficient hydrogen evolution.展开更多
基金Theme-based research scheme of Hong Kong Research Grant Council(RGC Ref:T13-402/17-N)National Natural Science Foundation of China(No.U1804251)。
文摘After reconstructing the anterior cruciate ligament(ACL),unsatisfactory bone tendon interface healing may often induce tunnel enlargement at the early healing stage.With good biological features and high formability,Magnesium-Zinc-Gadolinium(ZG21)wires are developed to bunch the tendon graft for matching the bone tunnel during transplantation.Microstructure,tensile strength,degradation,and cytotoxicity of ZG21 wire are evaluated.The rabbit model is used for assessing the biological effects of ZG21 wire by Micro-CT,histology,and mechanical test.The SEM/EDS,immunochemistry,and in vitro assessments are performed to investigate the underlying mechanism.Material tests demonstrate the high formability of ZG21 wire as surgical suture.Micro-CT shows ZG21 wire degradation accelerates tunnel bone formation,and histologically with earlier and more fibrocartilage regeneration at the healing interface.The mechanical test shows higher ultimate load in the ZG21 group.The SEM/EDS presents ZG21 wire degradation triggered calcium phosphate(Ca-P)deposition.IHC results demonstrate upregulation of Wnt3a,BMP2,and VEGF at the early phase and TGFβ3 and Type II collagen at the late phase of healing.In vitro tests also confirmed the Ca-P in the metal extract could elevate the expression of Wnt3a,βcatenin,ocn and opn to stimulate osteogenesis.Ex vivo tests of clinical samples indicated suturing with ZG21 wire did not weaken the ultimate loading of human tendon tissue.In conclusion,the ZG21 wire is feasible for tendon graft bunching.Its degradation products accelerated intra-tunnel endochondral ossification at the early healing stage and therefore enhanced bone-tendon interface healing in ACL reconstruction.
基金This work was supported by National Natural Sci-ence Foundation of China(No.81600827,No.U1804251,No.81600827 and No.51971134)the National Key R&D program of China(No.2016YFC1102103)+1 种基金the Science and Technology Commission of Shanghai(18441908000)Shanghai Jiao Tong University Biomedi-cal Engineering Research Fund(YG2019ZDA02).Dr.Jiawen Si wants to thank his wife Qifan Hu and daughter Jinnuo Si for their support,care and love over the past years,and say“thank god for sending you to me on angel’s wings”.
文摘To develop a biodegradable membrane with guided bone regeneration(GBR),a Mg-2.0Zn-1.0Gd alloy(wt.%,MZG)membrane with Ca-P coating was designed and fabricated in this study.The microstructure,hydrophilicity,in vitro degradation,cytotoxicity,antibacterial effect and in vivo regenerative performance for the membrane with and without Ca-P coating were evaluated.After coating,the membrane exhibited an enhance hydrophilicity and corrosion resistance,showed good in vitro cytocompatibility upon MC3T3E-1 cells,and exhibited excellent antibacterial effect against E.coli,Staphylococcus epidermis and Staphylococcus aureus,simultaneously.In vivo experiment using the rabbit calvarial defect model confirmed that Ca-P coated MZG membrane underwent progressive degradation without inflammatory reaction and significantly improved the new bone formation at both 1.5 and 3 months after the surgery.All the results strongly indicate that MZG with Ca-P coating have great potential for clinical application as GBR membranes.
基金support by the national key research and development plan(No.2016YFC1102100)the National Natural Science Founda-tion of China(Nos.51501110,51728202,11332013 and 51501115)+1 种基金the Natural Science Foundation of Shang-hai(15ZR1422600)the Shanghai Jiao Tong University Medical-engineering Cross Fund(No.YG2015MS66 and No.YG2014MS62).
文摘We prepare a new type of patented biodegradable biomedical Mg-Nd-Zn-Zr(JDBM)alloy system and impose double continuously extrusion(DCE)processing.The lowest processing temperature is 250℃for JDBM-2.1Nd and 310℃for JDBM-2.8Nd,which increases with the Nd concentration.The highest yield strength of 541 MPa is achieved in JDBM-2.1 Nd samples when extruded at 250℃and the elongation is about 3.7%.Moreover,the alloy with a lower alloying element content can reach a higher yield strength while that with a higher alloying element content can reach a larger elongation after DCE processing.However,when extruded under the same conditions,the alloy with a higher alloying contents exhibits better tensile properties.
基金the National Natural Science Foundation of China(Nos.51728202 and 51909165)the China Postdoctoral Science Foundation(Nos.2020TQ0109 and 2018M630986)+3 种基金the Shenzhen Peacock Plan(No.827-000113)the Science and Technology Planning Project of Guangdong Province(No.2016B050501005)the project Nanotechnology Based Functional Solutions(No.NORTE01-0145-FEDER-000019)Norte Portugal Regional Operational Programme(NORTE2020)under the PORTUGAL 2020。
文摘2D transition metal dichalcogenides(TMDs)have been considered as promising non-precious electrocatalysts for the hydrogen evolution reaction(HER).However,their limited active sites and poor electric conductivity pose a significant hurdle to their HER performance,resulting in a large overpotential.Here,we report the defect engineering in ultrathin tungsten telluride(WTe_(2))nanosheets with semimetal nature to improve hydrogen evolution effectively.We find that the oxygen plasma etching imposes a cutting effect on WTe_(2)nanosheets,resulting in a large number of tungsten vacancies.Particularly,the sample after plasma treatment for 10 min shows a feather-like structure with an overpotential of 251m V at 10 m A/cm~2and a Tafel slope of 94 m V/dec,which is 4 times lower than the Tafel slope of pristine nanosheets.Further first-principles calculations shed light on the evolution of defect-rich WTe_(2)nanosheets and offer rational explanation to their superiority in efficient hydrogen evolution.
