摘要
Zinc is generally considered to be one of the most promising materials to be used in biodegradable implants,and many zinc alloys have been optimized to improve implant biocompatibility,degradation,and mechanical properties.However,long-term degradation leads to the prolonged presence of degradation products,which risks foreign body reactions.Herein,we investigated the in vivo biocompatibility and degradation of a biodegradable Zn-Mg-Fe alloy osteosynthesis system in the frontal bone,mandible,and femur in beagles for 1 year.Results of the routine blood,biochemical,trace element,and histological analyses of multiple organs,peripheral blood CD4/CD8a levels,and serum interleukin 2 and 4 levels showed good biocompatibility of the Zn-Mg-Fe alloy.Zinc content analysis revealed zinc accumulation in adjacent bone tissue,but not in the liver,kidney,and spleen,which was related to the degradation of the Zn-Mg-Fe alloy.The alloy demonstrated a uniform slowing degradation rate in vivo.No degradation differences in the frontal bone,mandible,and femur were observed.The degradation products included zinc oxide[ZnO],zinc hydroxide[Zn(OH)_(2)],hydrozincite[Zn_(5)(OH)_(6)(CO_(3))_(2)],and hopeite[Zn_(3)(PO_(4))_(2)⋅4H_(2)O].The good biocompatibility and degradation properties of the Zn-Mg-Fe alloy render it a very attractive osteosynthesis system for clinical applications.
基金
This work was supported by Science and Technology Development Fund[grant number 2020JZ005]
National Key R&D Program of China[grant number 2018YFB1107100]
and Research project of National Key Laboratory[grant number 2018ZA04].
