3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark - Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Guimarães, Portugal.
ICVS/3B's-PT Associate Laboratory, Braga, Portugal.
Adv Healthc Mater. 2016 Jun;5(11):1364-75. doi: 10.1002/adhm.201501048. Epub 2016 Apr 5.
Anisotropically aligned electrospun nanofibrous scaffolds based on natural/synthetic polymer blends have been established as a reasonable compromise between biological and biomechanical performance for tendon tissue engineering (TE) strategies. However, the limited tensile properties of these biomaterials restrict their application in this field due to the load-bearing nature of tendon/ligament tissues. Herein, the use of cellulose nanocrystals (CNCs) as reinforcing nanofillers in aligned electrospun scaffolds based on a natural/synthetic polymer blend matrix, poly-ε-caprolactone/chitosan (PCL/CHT) is reported. The incorporation of small amounts of CNCs (up to 3 wt%) into tendon mimetic nanofiber bundles has a remarkable biomaterial-toughing effect (85% ± 5%, p < 0.0002) and raises the scaffolds mechanical properties to tendon/ligament relevant range (σ = 39.3 ± 1.9 MPa and E = 540.5 ± 83.7 MPa, p < 0.0001). Aligned PCL/CHT/CNC nanocomposite fibrous scaffolds meet not only the mechanical requirements for tendon TE applications but also provide tendon mimetic extracellular matrix (ECM) topographic cues, a key feature for maintaining tendon cell's morphology and behavior. The strategy proposed here may be extended to other anisotropic aligned nanofibrous scaffolds based on natural/synthetic polymer blends and enable the full exploitation of the advantages provided by their tendon mimetic fibrous structures in tendon TE.
基于天然/合成聚合物共混物的各向异性取向静电纺纳米纤维支架已被确立为肌腱组织工程（TE）策略中生物和生物力学性能之间的合理折衷。然而，由于肌腱/韧带组织的承载性质，这些生物材料的拉伸性能有限，限制了它们在该领域的应用。本文报道了将纤维素纳米晶体（CNC）用作基于天然/合成聚合物共混物基质的定向静电纺丝支架中的增强型纳米填料，该基质为聚己内酯/壳聚糖（PCL/CHT）。少量 CNCs（高达 3wt%）的掺入对肌腱模拟纳米纤维束具有显著的生物材料增韧效果（85%±5%，p<0.0002），并将支架的机械性能提高到肌腱/韧带相关的范围（σ=39.3±1.9MPa和 E=540.5±83.7MPa，p<0.0001）。定向 PCL/CHT/CNC 纳米复合材料纤维支架不仅满足肌腱 TE 应用的机械要求，而且还提供肌腱模拟细胞外基质（ECM）形貌线索，这是维持肌腱细胞形态和行为的关键特征。这里提出的策略可以扩展到其他基于天然/合成聚合物共混物的各向异性定向纳米纤维支架，并充分利用其肌腱模拟纤维结构在肌腱 TE 中的优势。
