Pauly Hannah M, Kelly Daniel J, Popat Ketul C, Trujillo Nathan A, Dunne Nicholas J, McCarthy Helen O, Haut Donahue Tammy L
School of Biomedical Engineering, Colorado State University, Fort Collins, CO, USA.
Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland; Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland; Department of Anatomy, Royal College of Surgeons in Ireland, Dublin 2, Ireland; Advanced Materials and Bioengineering Research Centre, Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland.
J Mech Behav Biomed Mater. 2016 Aug;61:258-270. doi: 10.1016/j.jmbbm.2016.03.022. Epub 2016 Mar 31.
Electrospun nanofibers are a promising material for ligamentous tissue engineering, however weak mechanical properties of fibers to date have limited their clinical usage. The goal of this work was to modify electrospun nanofibers to create a robust structure that mimics the complex hierarchy of native tendons and ligaments. The scaffolds that were fabricated in this study consisted of either random or aligned nanofibers in flat sheets or rolled nanofiber bundles that mimic the size scale of fascicle units in primarily tensile load bearing soft musculoskeletal tissues. Altering nanofiber orientation and geometry significantly affected mechanical properties; most notably aligned nanofiber sheets had the greatest modulus; 125% higher than that of random nanofiber sheets; and 45% higher than aligned nanofiber bundles. Modifying aligned nanofiber sheets to form aligned nanofiber bundles also resulted in approximately 107% higher yield stresses and 140% higher yield strains. The mechanical properties of aligned nanofiber bundles were in the range of the mechanical properties of the native ACL: modulus=158±32MPa, yield stress=57±23MPa and yield strain=0.38±0.08. Adipose derived stem cells cultured on all surfaces remained viable and proliferated extensively over a 7 day culture period and cells elongated on nanofiber bundles. The results of the study suggest that aligned nanofiber bundles may be useful for ligament and tendon tissue engineering based on their mechanical properties and ability to support cell adhesion, proliferation, and elongation.
电纺纳米纤维是用于韧带组织工程的一种很有前景的材料，然而，迄今为止纤维较弱的机械性能限制了它们的临床应用。这项工作的目标是对电纺纳米纤维进行改性，以创建一种强健的结构，模拟天然肌腱和韧带的复杂层次结构。本研究中制备的支架由平板中的随机或排列的纳米纤维或卷状纳米纤维束组成，这些结构模仿了主要承受拉伸负荷的软肌肉骨骼组织中束状单元的尺寸规模。改变纳米纤维的取向和几何形状会显著影响机械性能；最显著的是，排列的纳米纤维片具有最大的模量，比随机纳米纤维片高125%，比排列的纳米纤维束高45%。将排列的纳米纤维片改性形成排列的纳米纤维束还会使屈服应力提高约107%，屈服应变提高140%。排列的纳米纤维束的机械性能处于天然前交叉韧带机械性能的范围内：模量 = 158±32MPa，屈服应力 = 57±23MPa，屈服应变 = 0.38±0.08。在所有表面上培养的脂肪来源干细胞在7天的培养期内保持存活并大量增殖，并且细胞在纳米纤维束上伸长。该研究结果表明，基于其机械性能以及支持细胞黏附、增殖和伸长的能力，排列的纳米纤维束可能对韧带和肌腱组织工程有用。
