Morphological and mechanical characterization of 3D printed PLA scaffolds with controlled porosity for trabecular bone tissue replacement
Morphological and mechanical characterization of 3D printed PLA scaffolds with controlled porosity for trabecular bone tissue replacement
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DOI：
10.1016/j.msec.2020.111528
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发表时间：
2021-01-01
影响因子：
7.9
通讯作者：
Guedes, M.
中科院分区：
文献类型：
--
作者：
Baptista, R.;Guedes, M.
骨移植仍然是治疗骨科创伤或疾病的金标准方法。当这种解决方案是不可能的，支架是骨组织工程提供的可能性。为了支持再生过程，受损的骨组织被移除并被多孔支架结构替代。近年来，增材制造在生产具有所需性能的支架结构方面显示出巨大的潜力。在目前的工作中，使用最佳的制造参数3D打印了具有不同设计的PLA支架。通过将细丝偏移量从571 μ m改变到1333 μ m，获得具有三种不同孔隙率值的支架。在单调和动态压缩条件下，共测试了12种设计。数值分析显示与实验结果有很好的相关性，可以更好地评估支架的力学行为。在四个不同的应变水平上测量应力松弛，评估植入后支架的行为和随时间的静态响应。总体而言，正交设计提供了更好的性能，由于改善的材料沉积。对于低孔隙率的支架，在4%变形下松弛300 s后，平衡应力达到24 MPa，得到的平衡模量为428 MPa。总的来说，所获得的结果表明，使用PLA的3D打印可以应用于制造用于骨小梁置换的支架。
Bone transplant is still the gold standard approach when dealing with orthopedic trauma or disease. When this solution is not possible, scaffolding is a possibility provided by bone tissue engineering. To support the regeneration process, damaged bone tissue is removed and replaced by porous scaffold structures. In recent years, additive manufacturing has shown huge potential to produce scaffold structures with the required performance. In the current work, PLA scaffolds with different designs were 3D printed, using optimal manufacturing parameters. Scaffolds with three different porosity values were obtained by changing the filament offset from 571 to 1333 mu m. A total of twelve designs were tested under monotonic and dynamic compression conditions. Numerical analysis showed good correlation with experimental results, allowing for a better assessment of scaffold mechanical behavior. Stress relaxation was measured on four different strain levels, assessing scaffold's behavior after implantation and consequent static response over time. Overall, orthogonal design provided better performance, due to improved material deposition. With lower porosity scaffolds equilibrium stress reached 24 MPa after 300 s relaxation time under 4% deformation, and the obtained equilibrium modulus was 428 MPa. Overall, attained results show that 3D printing with PLA can be applied in the manufacture of scaffolds for trabecular bone replacement.