Biodegradable magnesium alloy WE43 porous scaffolds fabricated by laser powder bed fusion for orthopedic applications:Process optimization,in vitro and in vivo investigation  

作　　者：Jinge Liu Bingchun Liu Shuyuan Min Bangzhao Yin Bo Peng Zishi Yu Caimei Wang Xiaolin Ma Peng Wen Yun Tian Yufeng Zheng 

机构地区：[1]The State Key Laboratory of Tribology,Tsinghua University,Beijing,100084,China [2]Department of Mechanical Engineering,Tsinghua University,Beijing,100084,China [3]Department of Orthopaedics,Peking University Third Hospital,Beijing,100191,China [4]School of Materials Science and Engineering,Peking University,Beijing,100871,China [5]Engineering Research Center of Bone and Joint Precision Medicine,Ministry of Education,Beijing,100191,China [6]Beijing AKEC Medical Co.,Ltd.,Beijing,102200,China

出　　处：《Bioactive Materials》2022年第10期301-319,共19页生物活性材料（英文）

基　　金：funded by the National Key Research and Development Program of China(2018YFE0104200);National Natural Science Foundation of China(51875310,52175274,82172065)and AO Foundation(AOTAP21-47).

摘　　要：Laser powder bed fusion(L-PBF)of magnesium(Mg)alloy porous scaffolds is expected to solve the dual challenges from customized structures and biodegradable functions required for repairing bone defects.However,one of the key technical difficulties lies in the poor L-PBF process performance of Mg,contributed by the high susceptibility to oxidation,vaporization,thermal expansion,and powder attachment etc.This work investigated the influence of L-PBF energy input and scanning strategy on the formation quality of porous scaffolds by using WE43 powder,and characterized the microstructure,mechanical properties,biocompatibility,biodegradation and osteogenic effect of the as-built WE43 porous scaffolds.With the customized energy input and scanning strategy,the relative density of struts reached over 99.5%,and the geometrical error between the designed and the fabricated porosity declined to below 10%.Massive secondary phases including intermetallic precipitates and oxides were observed.The compressive strength(4.37-23.49 MPa)and elastic modulus(154.40-873.02 MPa)were comparable to those of cancellous bone.Good biocompatibility was observed by in vitro cell viability and in vivo implantation.The biodegradation of as-built porous scaffolds promoted the osteogenic effect,but the structural integrity devastated after 12 h by the immersion tests in Hank’s solution and after 4 weeks by the implantation in rabbits’femur,indicating an excessively rapid degradation rate.

关 键 词：Additive manufacturing Biodegradable metal Laser powder bed fusion Magnesium alloy Porous scaffold WE43 

分 类 号：R318[医药卫生—生物医学工程] R68[医药卫生—基础医学]