Somszor Katarzyna, Bas Onur, Karimi Fatemeh, Shabab Tara, Saidy Navid T, O'Connor Andrea J, Ellis Amanda V, Hutmacher Dietmar, Heath Daniel E
Department of Biomedical Engineering, The University of Melbourne, Victoria 3010, Australia.
Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia.
ACS Macro Lett. 2020 Dec 15;9(12):1732-1739. doi: 10.1021/acsmacrolett.0c00644. Epub 2020 Nov 16.
Biodegradable coronary artery stents are sought-after alternatives to permanent stents. These devices are designed to degrade after the blood vessel heals, leaving behind a regenerated artery. The original generation of clinically available biodegradable stents required significantly thicker struts (∼150 μm) than nondegradable ones to ensure sufficient mechanical strength. However, these thicker struts proved to be a key contributor to the clinical failure of the stents. A current challenge lies in the fabrication of stents that possess both thin struts and adequate mechanical strength. In this contribution, we describe a method for the bottom-up, additive manufacturing of biodegradable composite stents with ultrathin fibers and superior mechanical properties compared to the base polymer. Specifically, we illustrate that melt electrowriting (MEW) can be used to 3D print composite structures with thin struts (60-80 μm) and a high degree of geometric complexity required for stenting applications. Additionally, this technology allows additive manufacture of personalized stents that are customized to a patient's unique anatomy and disease state. Furthermore, we illustrate that polycaprolactone-reduced graphene oxide nanocomposites have superior mechanical properties compared to original polycaprolactone without detriment to the material's cytocompatibility and that customizable stent-like structures can be fabricated from these materials with struts as thin as 60 μm, well below the target value for clinical use of 80 μm.
可生物降解冠状动脉支架是永久性支架备受追捧的替代品。这些装置设计用于在血管愈合后降解，留下再生的动脉。第一代临床可用的可生物降解支架需要比不可降解支架厚得多的支柱（约150微米）以确保足够的机械强度。然而，这些较厚的支柱被证明是支架临床失败的关键因素。当前的一个挑战在于制造既具有细支柱又具有足够机械强度的支架。在本论文中，我们描述了一种自下而上的增材制造方法，用于制造具有超薄纤维且与基础聚合物相比具有优异机械性能的可生物降解复合支架。具体而言，我们表明熔体静电纺丝（MEW）可用于3D打印具有细支柱（60 - 80微米）和支架应用所需高度几何复杂性的复合结构。此外，该技术允许增材制造根据患者独特的解剖结构和疾病状态定制的个性化支架。再者，我们表明聚己内酯 - 还原氧化石墨烯纳米复合材料与原始聚己内酯相比具有优异的机械性能，同时不损害材料的细胞相容性，并且可以用这些材料制造出支柱薄至60微米的可定制支架状结构，远低于临床使用的目标值80微米。
