3D printing and characterization of a soft and biostable elastomer with high flexibility and strength for biomedical applications
3D printing and characterization of a soft and biostable elastomer with high flexibility and strength for biomedical applications
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DOI：
10.1016/j.jmbbm.2020.103649
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发表时间：
2020-04-01
影响因子：
3.9
通讯作者：
Kang, Sung Hoon
中科院分区：
文献类型：
--
作者：
Bachtiar, Emilio O.;Erol, Ozan;Kang, Sung Hoon
3D打印的最新进展通过以低成本、可定制和小批量制造的方式制造复杂和功能设备，使生物医学工程发生了革命性的变化。软弹性体对于生物医学应用尤其重要，因为它们可以提供与组织相似的机械性能，并具有更好的生物相容性。然而，具有3D可打印性的生物相容弹性体很少，对生物相容3D可打印弹性体的材料性能知之甚少。在这里，我们报告了一种新的3D打印框架，以最小的缺陷打印出柔软的、生物相容的、生物稳定的聚碳酸酯基氨基甲酸酯有机硅(PCU-sil)。我们对材料的流变性和热性能进行了系统的表征，以指导3D打印工艺，并确定了一系列工艺条件。通过参数研究确定最佳打印参数，如打印速度、温度和层高，旨在最小化孔隙率，同时最大化3D打印样品的几何精度，如通过microCT评估的那样。我们还对3D打印结构在准静态和循环载荷下的力学性能、降解行为和生物相容性进行了表征。3D打印材料的杨氏模数为6.9+/-0.85 Mpa，破坏应变为457+/-37.7%，同时表现出良好的细胞存活率。最后，打印了顺应性和独立式结构，包括患者特定的心脏模型和分叉动脉结构，以展示3D打印材料的多功能性。我们预计，这项工作中提出的3D打印框架不仅将为PCU-sil开辟新的可能性，还将为其他软的、生物兼容的和热塑性聚合物在各种生物医学应用中开辟新的可能性，这些应用需要结合生物相容性的高柔韧性和强度，如血管植入物、心脏瓣膜和导管。
Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about the material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via microCT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young's modulus of 6.9 +/- 0.85 MPa and a failure strain of 457 +/- 37.7% while exhibiting good cell viability. Finally, compliant and freestanding structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not only for PCU-Sil, but also for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters.