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

Bioactive Materials

Bingchun Liu¹  Xiaolin Ma¹  Yun Tian¹  Bangzhao Yin²  Zishi Yu²  Shuyuan Min³  Bo Peng³  Caimei Wang⁴  Jinge Liu⁴  Yufeng Zheng⁴  Peng Wen⁴ 

[1] Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China;Engineering Research Center of Bone and Joint Precision Medicine, Ministry of Education, Beijing, 100191, China;Department of Orthopaedics, Peking University Third Hospital, Beijing, 100191, China;The State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China;

关键词: Additive manufacturing;    Biodegradable metal;    Laser powder bed fusion;    Magnesium alloy;    Porous scaffold;    WE43;   

DOI  :  

来源: DOAJ

【 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.

【 授权许可】

Unknown