Magnesium(Mg)–based alloys are becoming attractive materials for medical applications as temporary bone implants for support of fracture healing,e.g.as a suture anchor.Due to their mechanical properties and biocompat...Magnesium(Mg)–based alloys are becoming attractive materials for medical applications as temporary bone implants for support of fracture healing,e.g.as a suture anchor.Due to their mechanical properties and biocompatibility,they may replace titanium or stainless-steel implants,commonly used in orthopedic field.Nevertheless,patient safety has to be assured by finding a long-term balance between metal degradation,osseointegration,bone ultrastructure adaptation and element distribution in organs.In order to determine the implant behavior and its influence on bone and tissues,we investigated two Mg alloys with gadolinium contents of 5 and 10 wt percent in comparison to permanent materials titanium and polyether ether ketone.The implants were present in rat tibia for 10,20 and 32 weeks before sacrifice of the animal.Synchrotron radiation-based micro computed tomography enables the distinction of features like residual metal,degradation layer and bone structure.Additionally,X-ray diffraction and X-ray fluorescence yield information on parameters describing the bone ultrastructure and elemental composition at the bone-to-implant interface.Finally,with element specific mass spectrometry,the elements and their accumulation in the main organs and tissues are traced.The results show that Mg-xGd implants degrade in vivo under the formation of a stable degradation layer with bone remodeling similar to that of Ti after 10 weeks.No accumulation of Mg and Gd was observed in selected organs,except for the interfacial bone after 8 months of healing.Thus,we confirm that Mg-5Gd and Mg-10Gd are suitable material choices for bone implants.展开更多
基金This publication is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sk lodowska-Curie grant,agreement No 811226Röntgen-Angström Cluster in project SynchroLoad(05K16CGA)+5 种基金Swedish Research Council 2015-06109German Bundesministerium für Bildung und Forschung in project MgBone(05K16CGB)We acknowledge DESY(Hamburg,Germany),a member of the Helmholtz Association HGF,for the provision of experimental facilities.Parts of this research were carried out at PETRA IIIThe authors would like to thank Diamond Light Source for beamtime(proposal MG25078)Miguel Gomez Gonzalez and Julia Parker for assistance during the experiment at the I14 beamline and during the data analysisThis research was carried out in collaboration with the Quantitative Bio Element Analysis and Mapping(QBEAM)Center at Michigan State University and The National Research Resource for Quantitative Elemental Mapping for the Life Sciences(QE-Map)under Grant P41 GM135018(as well as Grant S10OD026786)from the National Institute of General Medical Sciences of the National Institutes of Health.
文摘Magnesium(Mg)–based alloys are becoming attractive materials for medical applications as temporary bone implants for support of fracture healing,e.g.as a suture anchor.Due to their mechanical properties and biocompatibility,they may replace titanium or stainless-steel implants,commonly used in orthopedic field.Nevertheless,patient safety has to be assured by finding a long-term balance between metal degradation,osseointegration,bone ultrastructure adaptation and element distribution in organs.In order to determine the implant behavior and its influence on bone and tissues,we investigated two Mg alloys with gadolinium contents of 5 and 10 wt percent in comparison to permanent materials titanium and polyether ether ketone.The implants were present in rat tibia for 10,20 and 32 weeks before sacrifice of the animal.Synchrotron radiation-based micro computed tomography enables the distinction of features like residual metal,degradation layer and bone structure.Additionally,X-ray diffraction and X-ray fluorescence yield information on parameters describing the bone ultrastructure and elemental composition at the bone-to-implant interface.Finally,with element specific mass spectrometry,the elements and their accumulation in the main organs and tissues are traced.The results show that Mg-xGd implants degrade in vivo under the formation of a stable degradation layer with bone remodeling similar to that of Ti after 10 weeks.No accumulation of Mg and Gd was observed in selected organs,except for the interfacial bone after 8 months of healing.Thus,we confirm that Mg-5Gd and Mg-10Gd are suitable material choices for bone implants.
