1 Department of Basic Medical Science, Purdue University College of Veterinary Medicine and Department of Biomedical Engineering, Weldon School of Engineering, Purdue University , West Lafayette, Indiana.
2 Department of Orthopaedic Surgery, Duke University , Durham, North Carolina.
Tissue Eng Part A. 2017 Sep;23(17-18):958-967. doi: 10.1089/ten.TEA.2016.0470.
Various biomaterial technologies are promising for tissue engineering, including electrospinning, but commercial scale-up of throughput is difficult. The goal of the study was to evaluate meltblown fabrics as candidate scaffolds for rotator cuff tendon tissue engineering. Meltblown poly(lactic acid) fabrics were produced with several polymer crystallinities and airflow velocities [500(low), 900(medium) or 1400(high) mair/h/m fabric]. Fiber diameter, alignment, and baseline bidirectional tensile mechanical properties were evaluated. Attachment and spreading of human adipose-derived stem cells (hASCs) were evaluated over 3 days immediately following seeding. After initial screening, the fabric with the greatest Young's modulus and yield stress was selected for 28-day in vitro culture and for evaluation of tendon-like extracellular matrix production and development of mechanical properties. As expected, airflow velocity of the polymer during meltblowing demonstrated an inverse relationship with fiber diameter. All fabrics exhibited fiber alignment parallel to the direction of collector rotation. All fabrics demonstrated mechanical anisotropy at baseline. Cells attached, proliferated, and spread on all fabrics over the initial three-day culture period. Consistent with the observed loss of integrity of the unseeded biomaterial, hASC-seeded scaffolds demonstrated a significant decrease in Young's modulus over 28 days of culture. However, dsDNA, sulfated glycosaminoglycan, and collagen content increased significantly over 28 days. Histology and polarized light microscopy demonstrated collagen deposition and alignment throughout the thickness of the scaffolds. While fiber diameters approximated an order of magnitude greater than those previously reported for electrospun scaffolds intended for tendon tissue engineering, they were still within the range of collagen fiber diameters found in healthy tendon. The extent of matrix production and alignment was similar to that previously observed for multilayered electrospun scaffolds. While the Young's modulus of scaffolds after 28 days of culture was lower than native rotator cuff tendon, it approximated that reported previously following culture of electrospun scaffolds and was on the same order of magnitude as of current Food and Drug Administration-approved patches for rotator cuff augmentation. Together, these data suggest that with minor polymer and parameter modifications, meltblown scaffolds could provide an economical, high-throughput production alternative method to electrospinning for use in rotator cuff tendon tissue engineering.
各种生物材料技术在组织工程中具有应用前景，包括静电纺丝，但商业规模扩大的产量是困难的。本研究的目的是评估熔喷织物作为肩袖肌腱组织工程候选支架。使用几种聚合物结晶度和气流速度[500（低）、900（中）或 1400（高）mair/h/m 织物]生产熔喷聚乳酸织物。评估纤维直径、排列和基本双向拉伸力学性能。接种后立即评估人脂肪来源干细胞（hASC）的附着和扩展情况，持续 3 天。经过初步筛选，选择杨氏模量和屈服应力最大的织物进行 28 天体外培养，并评估腱样细胞外基质的产生和力学性能的发展。正如预期的那样，聚合物在熔喷过程中的气流速度与纤维直径呈反比关系。所有织物的纤维均沿收集器旋转方向平行排列。所有织物在基线时均表现出各向异性。细胞在最初的 3 天培养期间附着、增殖并在所有织物上扩展。与观察到的未接种生物材料完整性丧失一致，hASC 接种支架在培养 28 天后杨氏模量显著降低。然而，dsDNA、硫酸化糖胺聚糖和胶原蛋白含量在 28 天内显著增加。组织学和偏光显微镜显示胶原蛋白在支架的整个厚度上沉积和排列。尽管纤维直径与先前报道的用于肌腱组织工程的静电纺丝支架相当，但仍在健康肌腱中发现的胶原蛋白纤维直径范围内。基质产生和排列的程度与先前观察到的多层静电纺丝支架相似。尽管培养 28 天后支架的杨氏模量低于天然肩袖肌腱，但它与先前报道的静电纺丝支架培养后的杨氏模量相近，与目前食品和药物管理局批准的肩袖增强补丁的杨氏模量相近。综上所述，这些数据表明，通过对聚合物和参数进行微小修改，熔喷支架可以为肩袖肌腱组织工程提供一种经济高效、高通量的生产替代静电纺丝方法。
