State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China; Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
Department of Dental Materials, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing Key Laboratory of Digital Stomatology, Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, NMPA Key Laboratory for Dental Materials, Beijing 100081, China.
Biomater Adv. 2023 Oct;153:213571. doi: 10.1016/j.bioadv.2023.213571. Epub 2023 Jul 31.
Alloying and structural design provide flexibility to modulate performance of biodegradable porous implants manufactured by laser powder bed fusion (L-PBF). Herein, bulk Zn-0.8Li-0.1Mg was first fabricated to indicate the influence of the ternary alloy system on strengthening effect. Porous scaffolds with different porosities, including 60 % (P60), 70 % (P70) and 80 % (P80), were designed and fabricated to study the influence of porosity on mechanical properties, in vitro degradation behavior, biocompatibility and osteogenic ability. Pure Zn (Zn-P70) scaffolds with a porosity of 70 % were utilized for the comparison. The results showed Zn-0.8Li-0.1Mg bulks had an ultimate tensile strength of 460.78 ± 5.79 MPa, which was more than 3 times that of pure Zn ones and was the highest value ever reported for Zn alloys fabricated by L-PBF. The compressive strength (CS) and elastic modulus (E) of scaffolds decreased with increasing porosities. The CS of P70 scaffolds was 24.59 MPa, more than 2 times that of Zn-P70. The weight loss of scaffolds during in vitro immersion increased with increasing porosities. Compared with Zn-P70, a lower weight loss, better biocompatibility and improved osteogenic ability were observed for P70 scaffolds. P70 scaffolds also exhibited the best biocompatibility and osteogenic ability among all the used porosities. Influence mechanism of alloying elements and structural porosities on mechanical behaviors, in vitro biodegradation behavior, biocompatibility and osteogenic ability of scaffolds were discussed using finite element analysis and the characterization of degradation products. The results indicated that the proper design of alloying and porosity made Zn-0.8Li-0.1Mg scaffolds promising for biodegradable applications.
合金化和结构设计为通过激光粉末床融合 (L-PBF) 制造的可生物降解多孔植入物的性能调节提供了灵活性。在此，首次制备了块状 Zn-0.8Li-0.1Mg，以表明三元合金体系对强化效果的影响。设计并制备了具有不同孔隙率的多孔支架，包括 60%（P60）、70%（P70）和 80%（P80），以研究孔隙率对力学性能、体外降解行为、生物相容性和成骨能力的影响。使用孔隙率为 70%的纯 Zn（Zn-P70）支架进行比较。结果表明，Zn-0.8Li-0.1Mg 块状物的极限拉伸强度为 460.78 ± 5.79 MPa，是纯 Zn 的 3 倍以上，是 L-PBF 制造的 Zn 合金的最高值。支架的抗压强度（CS）和弹性模量（E）随孔隙率的增加而降低。P70 支架的 CS 为 24.59 MPa，是 Zn-P70 的 2 倍以上。支架在体外浸泡过程中的重量损失随孔隙率的增加而增加。与 Zn-P70 相比，P70 支架具有更低的重量损失、更好的生物相容性和改善的成骨能力。在所有使用的孔隙率中，P70 支架表现出最好的生物相容性和成骨能力。使用有限元分析和降解产物的表征讨论了合金元素和结构孔隙率对支架力学性能、体外生物降解行为、生物相容性和成骨能力的影响机制。结果表明，合金化和孔隙率的适当设计使 Zn-0.8Li-0.1Mg 支架在可生物降解应用中具有广阔的前景。
