Sharma Arjun, Smith James A, Kurtz Michael A, Derr Tabitha, DeSantis Paul M, Bock Ryan M, Kurtz Steven M
Implant Research Core, Drexel University School of Biomedical Engineering, Science, and Health Systems, Philadelphia, PA, USA.
Implant Research Core, Drexel University School of Biomedical Engineering, Science, and Health Systems, Philadelphia, PA, USA.
J Mech Behav Biomed Mater. 2025 Nov;171:107141. doi: 10.1016/j.jmbbm.2025.107141. Epub 2025 Jul 17.
Continuous carbon fiber-reinforced polyetherketoneketone (CCF-PEKK) is a thermoplastic composite with properties suitable for trauma plate applications (elastic modulus, strength, radiolucency, and inertness). However, components manufactured by fused filament fabrication (FFF) often display non-uniform (anisotropic) mechanical properties and contain microstructural voids. To address these limitations, we investigated a hybrid-manufacturing approach, combining FFF with continuous carbon fiber reinforcement followed by uniaxial compression molding. Here, we asked: 1. Can layup orientation be tuned to replicate the mechanical stiffness of cortical bone in flexion? 2.) How does the structure of the different layups influence fracture behavior? and 3.) Do silicon nitride (SiN) (a bioactive ceramic with antimicrobial properties) embedded particulate coatings affect flexural or fracture behavior? To answer these research questions, we fabricated CCF-PEKK plates with three fiber layups (0°/90°, +45°/-45°, and 0°/90°/+45°/-45°) with the goal of approaching the flexural modulus of cortical bone (1.7-16.3 GPa). Next, half of the hybrid-specimens were spray-coated with submicron SiN powder. Four-point bending tests demonstrated that fiber orientation significantly influenced flexural modulus and strength. The 0°/90° layup exhibited the highest flexural modulus (67.6 GPa) and strength (1020 MPa), while the +45°/-45° configuration showed the lowest values (15.6 GPa, 217 MPa), but displayed superior load dissipation in axial fiber orientations and was able to reproduce moduli values akin to those of cortical bone range. SEM analysis confirmed uniform SiN coating distribution, with no observable impact on crack initiation or propagation. No difference (p > 0.01) in flexural modulus or strength was observed between the uncoated and coated specimens, suggesting that SiN is not associated with static flexural properties of CCF-PEKK. These findings support the feasibility of hybrid-manufactured CCF-PEKK trauma plates as potential alternatives to conventional metallic implants. Further investigations into the long-term fatigue behavior and bioactivity of SiN coatings are warranted.
连续碳纤维增强聚醚酮酮（CCF-PEKK）是一种热塑性复合材料，其性能适用于创伤接骨板应用（弹性模量、强度、射线可透过性和惰性）。然而，通过熔融长丝制造（FFF）生产的部件通常表现出不均匀（各向异性）的机械性能，并且含有微观结构孔隙。为了解决这些局限性，我们研究了一种混合制造方法，将FFF与连续碳纤维增强相结合，然后进行单轴压缩成型。在此，我们提出以下问题：1. 铺层方向能否调整以复制皮质骨在弯曲时的机械刚度？2. 不同铺层的结构如何影响骨折行为？以及3. 嵌入的氮化硅（SiN）（一种具有抗菌特性的生物活性陶瓷）颗粒涂层是否会影响弯曲或骨折行为？为了回答这些研究问题，我们制造了具有三种纤维铺层（0°/90°、+45°/-45°和0°/90°/+45°/-45°）的CCF-PEKK接骨板，目标是接近皮质骨的弯曲模量（1.7 - 16.3 GPa）。接下来，一半的混合试样用亚微米SiN粉末进行喷涂。四点弯曲试验表明，纤维方向显著影响弯曲模量和强度。0°/90°铺层表现出最高的弯曲模量（67.6 GPa）和强度（1020 MPa），而+45°/-45°构型显示出最低值（15.6 GPa，217 MPa），但在轴向纤维方向上表现出优异的载荷耗散能力，并且能够重现类似于皮质骨范围的模量值。扫描电子显微镜（SEM）分析证实了SiN涂层分布均匀，对裂纹萌生或扩展没有可观察到的影响。在未涂层和涂层试样之间未观察到弯曲模量或强度的差异（p > 0.01），这表明SiN与CCF-PEKK的静态弯曲性能无关。这些发现支持了混合制造的CCF-PEKK创伤接骨板作为传统金属植入物潜在替代品的可行性。有必要对SiN涂层的长期疲劳行为和生物活性进行进一步研究。
