Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradati...Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradation,poor biotribology performance,and lack of vascularization and antibacterial activity are not conducive to bone-fixation applications.In this study,an in situ Mg_(2)Ge/Mg-Cu-P composite with a nominal composition of Mg-10Ge-2Cu-0.5P(denoted MGCP)was prepared via phosphorus(P)-modified casting followed by hot extrusion for biodegradable bone-fixation applications.For comparison,an in situ Mg_(2)Ge/Mg-Cu composite(Mg-10Ge-2Cu,denoted MGC)was prepared under the same conditions without P-modification.The hot-extruded(HE)MGCP sample showed significantly improved corrosion resistance with corrosion rates of 2.2 mm/y and 2.51 mm/y as measured by potentiodynamic-polarization and hydrogen-release testing in Dulbecco’s Modified Eagle Medium supplemented with fetal bovine serum(denoted DMEM).The HE MGCP also exhibited notably enhanced mechanical properties and biotribological resistance in DMEM,with an σ_(UTS) of ~304.2 MPa,σ_(TYS) of ~202.5 MPa,elongation of ~12.3%,σ_(UCS) of 769.0 MPa,σ_(CYS) of 208.0 MPa,and Brinell hardness of 105.3 HB,along with smallerσ_(TYS) andσ_(CYS) decreases after 3 d of immersion in Hanks’solution.In comparison to pure titanium and Mg,the HE MGCP demonstrated much greater cytocompatibility,angiogenic capacity,and osteogenic differentiation and mineralization capability.Furthermore,the HE MGCP displayed markedly higher in vitro antibacterial activity,in vivo antibacterial and anti-inflammatory ability,and good biosafety in a rat subcutaneous-implantation model compared to pure titanium and Mg,indicating significant potential for biodegradable bone-fixation applications.展开更多
基金supported by the Zhejiang Public Welfare Technology Application Research Project of China(No.LTGY24H140002,No.LTGY23H140002,No.LGF22H140008)Wenzhou Medical University Basic Scientific Research Expenses Project(KYYW202331)the financial support for this research by the Australian Research Council(ARC)through the Discovery Project(DP240101131).
文摘Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradation,poor biotribology performance,and lack of vascularization and antibacterial activity are not conducive to bone-fixation applications.In this study,an in situ Mg_(2)Ge/Mg-Cu-P composite with a nominal composition of Mg-10Ge-2Cu-0.5P(denoted MGCP)was prepared via phosphorus(P)-modified casting followed by hot extrusion for biodegradable bone-fixation applications.For comparison,an in situ Mg_(2)Ge/Mg-Cu composite(Mg-10Ge-2Cu,denoted MGC)was prepared under the same conditions without P-modification.The hot-extruded(HE)MGCP sample showed significantly improved corrosion resistance with corrosion rates of 2.2 mm/y and 2.51 mm/y as measured by potentiodynamic-polarization and hydrogen-release testing in Dulbecco’s Modified Eagle Medium supplemented with fetal bovine serum(denoted DMEM).The HE MGCP also exhibited notably enhanced mechanical properties and biotribological resistance in DMEM,with an σ_(UTS) of ~304.2 MPa,σ_(TYS) of ~202.5 MPa,elongation of ~12.3%,σ_(UCS) of 769.0 MPa,σ_(CYS) of 208.0 MPa,and Brinell hardness of 105.3 HB,along with smallerσ_(TYS) andσ_(CYS) decreases after 3 d of immersion in Hanks’solution.In comparison to pure titanium and Mg,the HE MGCP demonstrated much greater cytocompatibility,angiogenic capacity,and osteogenic differentiation and mineralization capability.Furthermore,the HE MGCP displayed markedly higher in vitro antibacterial activity,in vivo antibacterial and anti-inflammatory ability,and good biosafety in a rat subcutaneous-implantation model compared to pure titanium and Mg,indicating significant potential for biodegradable bone-fixation applications.
