Department of Biomedical Engineering, University of Memphis, 330 Engineering Technology, 3806 Norriswood Ave, Memphis, TN, 38152, USA; Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center, 956 Court Ave, Suite E226, Memphis, TN, 38163, USA.
Department of Biomedical Engineering, University of Memphis, 330 Engineering Technology, 3806 Norriswood Ave, Memphis, TN, 38152, USA.
J Mech Behav Biomed Mater. 2022 Jun;130:105207. doi: 10.1016/j.jmbbm.2022.105207. Epub 2022 Mar 29.
The ideal "off the shelf" tissue engineering, small-diameter (SD) vascular graft hinges on designing a scaffold to act as a template that facilitates transmural ingrowth of capillaries to regenerate an endothelized neointimal surface. Towards this goal, we explored two types of near-field electrospun (NFES) polydioxanone (PDO) architectures, as SD vascular graft scaffolds. The first architecture type consisted of a 200 × 200 μm and 500 × 500 μm grid geometry with random fiber infill, while the second architecture consisted of aligned fibers written in a 45°/45° and 20°/70° offset from the long axis written, both on a 4 mm diameter cylindrical mandrel. These vascular graft scaffolds were evaluated for their effective pore size, mechanical properties, and platelet-material interactions compared to traditionally electrospun (TES) scaffolds and Gore-Tex® vascular grafts. It was found that effective pore size, given by 9.9 and 97 μm microsphere filtration through the scaffold wall for NFES scaffolds, was significantly more permeable compared to TES scaffolds and Gore-Tex® vascular grafts. Furthermore, ultimate tensile strength, percent elongation, suture retention, burst pressure, and Young's modulus were all tailorable compared to TES scaffold characterization. Lastly, platelet adhesion was attenuated on NFES scaffolds compared to TES scaffold which approximates the low level of platelet adhesion measured on Gore-Tex®, with all samples showing minimal platelet activation given by P-selectin surface expression. Together, these results suggest a highly tailorable process for the creation of the next generation of small-diameter vascular grafts.
理想的“现成”组织工程小直径（SD）血管移植物取决于设计一种支架作为模板，促进毛细血管跨壁生长以再生内皮化的新生内膜表面。为此，我们探索了两种近场静电纺丝（NFES）聚对二氧环己酮（PDO）结构，作为 SD 血管移植物支架。第一种结构类型由 200×200μm 和 500×500μm 的网格几何形状和随机纤维填充组成，而第二种结构由在 4mm 直径圆柱芯上以 45°/45°和 20°/70°的角度从长轴写入的对齐纤维组成。与传统静电纺丝（TES）支架和 Gore-Tex®血管移植物相比，评估了这些血管移植物支架的有效孔径、机械性能和血小板-材料相互作用。发现有效孔径，通过支架壁的 9.9 和 97μm 微球过滤，与 TES 支架和 Gore-Tex®血管移植物相比，NFES 支架的渗透性显著更高。此外，与 TES 支架相比，拉伸强度、伸长率、缝线保持力、爆裂压力和杨氏模量均具有可调节性。最后，与 TES 支架相比，血小板黏附在 NFES 支架上减弱，这与在 Gore-Tex®上测量到的低水平血小板黏附相似，所有样品的 P-选择素表面表达均表明血小板激活最小。总之，这些结果表明，下一代小直径血管移植物的制造具有高度可调节的过程。
