Coburn Brandon, Salary Roozbeh Ross
Department of Mechanical & Industrial Engineering, Marshall University, Huntington, WV 25755, USA.
Department of Biomedical Engineering, Marshall University, Huntington, WV 25755, USA.
Bioengineering (Basel). 2025 Apr 14;12(4):416. doi: 10.3390/bioengineering12040416.
The patient-specific treatment of bone fractures using porous osteoconductive scaffolds has faced significant clinical challenges due to insufficient mechanical strength and bioactivity. These properties are essential for osteogenesis, bone bridging, and bone regeneration. Therefore, it is crucial to develop and characterize biocompatible, biodegradable, and mechanically robust scaffolds for effective bone regeneration. The objective of this study is to systematically investigate the mechanical performance of SimuBone, a medical-grade biocompatible and biodegradable material, using 10 distinct triply periodic minimal surface (TPMS) designs with various internal structures. To assess the material's tensile properties, tensile structures based on ASTM D638-14 (Design IV) were fabricated, while standard torsion structures were designed and fabricated to evaluate torsional properties. Additionally, this work examined the compressive properties of the 10 TPMS scaffold designs, parametrically designed in the Rhinoceros 3D environment and subsequently fabricated using fused deposition modeling (FDM) additive manufacturing. The FDM fabrication process utilized a microcapillary nozzle (heated to 240 °C) with a diameter of 400 µm and a print speed of 10 mm/s, depositing material on a heated surface maintained at 60 °C. It was observed that SimuBone had a shear modulus of 714.79 ± 11.97 MPa as well as an average yield strength of 44 ± 1.31 MPa. Scaffolds fabricated with horizontal material deposition exhibited the highest tensile modulus (5404.20 ± 192.30 MPa), making them ideal for load-bearing applications. Also, scaffolds with large voids required thicker walls to prevent collapse. The scaffold design demonstrated high vertical stiffness but moderate horizontal stiffness, indicating anisotropic mechanical behavior. The scaffold design balanced mechanical stiffness and porosity, making it a promising candidate for bone tissue engineering. Overall, the outcomes of this study pave the way for the design and fabrication of scaffolds with optimal properties for the treatment of bone fractures.
由于机械强度和生物活性不足，使用多孔骨传导支架对骨折进行个性化治疗面临重大临床挑战。这些特性对于骨生成、骨桥接和骨再生至关重要。因此，开发和表征具有生物相容性、可生物降解且机械性能强劲的支架以实现有效的骨再生至关重要。本研究的目的是系统地研究SimuBone（一种医用级生物相容性和可生物降解材料）的机械性能，该材料采用10种具有不同内部结构的独特三重周期极小曲面（TPMS）设计。为了评估该材料的拉伸性能，制作了基于ASTM D638 - 14（设计IV）的拉伸结构，同时设计并制作了标准扭转结构以评估扭转性能。此外，这项工作研究了在Rhinoceros 3D环境中进行参数化设计并随后使用熔融沉积建模（FDM）增材制造技术制作的10种TPMS支架设计的压缩性能。FDM制造工艺使用直径为400 µm的微毛细管喷嘴（加热至240°C），打印速度为10 mm/s，将材料沉积在保持在60°C的加热表面上。观察到SimuBone的剪切模量为714.79±11.97 MPa，平均屈服强度为44±1.31 MPa。采用水平材料沉积制作的支架表现出最高的拉伸模量（5404.20±192.30 MPa），使其成为承重应用的理想选择。此外，具有大孔隙的支架需要更厚的壁以防止坍塌。该支架设计显示出高垂直刚度但水平刚度适中，表明其具有各向异性的机械行为。该支架设计在机械刚度和孔隙率之间取得了平衡，使其成为骨组织工程的有前途的候选材料。总体而言，本研究的结果为设计和制造具有最佳性能的骨折治疗支架铺平了道路。
