Tropoelastin-Coated Tendon Biomimetic Scaffolds Promote Stem Cell Tenogenic Commitment and Deposition of Elastin-Rich Matrix
Tropoelastin-Coated Tendon Biomimetic Scaffolds Promote Stem Cell Tenogenic Commitment and Deposition of Elastin-Rich Matrix
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DOI：
10.1021/acsami.9b04616
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发表时间：
2019-06-05
影响因子：
9.5
通讯作者：
Gomes, Manuela E.
中科院分区：
文献类型：
--
作者：
Almeida, Helena;Domingues, Rui M. A.;Gomes, Manuela E.
重建生物物理和生物化学天然微环境的肌腱组织工程策略具有更大的实现再生的潜力。在这里，我们开发了肌腱仿生支架，使用聚-ε-己内酯，壳聚糖和纤维素纳米晶体的机械性能纱线，从纳米到宏观尺度重建固有的肌腱层次结构。然后通过聚多巴胺（PDA）连接用弹性蛋白原（TROPO）包被这些细胞，以模拟天然细胞外基质（ECM）组成和弹性。PDA和TROPO涂层都降低了表面硬度，而不掩蔽下面的基材。我们发现，人类脂肪来源的干细胞（hASCs）接种到这些TROPO仿生支架更迅速地获得他们的梭形形态和高纵横比肌腱细胞的特点。免疫细胞化学显示，PDA和TROPO包被的表面促进了hASC向生腱谱系的分化，肌腱相关标志物巩膜轴蛋白和腱调节蛋白的持续表达长达21天的培养。此外，这些表面能够沉积肌腱样ECM，并得到I型和III型胶原蛋白、腱生蛋白和核心蛋白聚糖表达的支持。基因表达分析显示，与对照组相比，在TROPO存在下成骨和纤维化标志物下调，表明适当的ECM沉积。值得注意的是，由于明显的弹性蛋白合成和沉积，暴露于TROPO的分化细胞获得了弹性蛋白生成谱，与PDA涂覆和未涂覆的条件相比，有助于形成更模拟的基质。总之，我们的仿生基质结合生物物理和生物线索调节干细胞的行为，增强其长期tenogenic承诺和生产的弹性蛋白丰富的ECM。
Tendon tissue engineering strategies that recreate the biophysical and biochemical native microenvironment have a greater potential to achieve regeneration. Here, we developed tendon biomimetic scaffolds using mechanically competent yarns of poly-epsilon-caprolactone, chitosan, and cellulose nanocrystals to recreate the inherent tendon hierarchy from a nano-to-macro scale. These were then coated with tropoelastin (TROPO) through polydopamine (PDA) linking, to mimic the native extracellular matrix (ECM) composition and elasticity. Both PDA and TROPO coatings decreased surface stiffness without masking the underlying substrate. We found that human adipose-derived stem cells (hASCs) seeded onto these TROPO biomimetic scaffolds more rapidly acquired their spindle-shape morphology and high aspect ratio characteristic of tenocytes. Immunocytochemistiy shows that the PDA and TROPO-coated surfaces boosted differentiation of hASCs toward the tenogenic lineage, with sustained expression of the tendon-related markers scleraxis and tenomodulin up to 21 days of culture. Furthermore, these surfaces enabled the deposition of a tendon-like ECM, supported by the expression of collagens type I and III, tenascin, and decorin. Gene expression analysis revealed a downregulation of osteogenic and fibrosis markers in the presence of TROPO when compared with the control groups, suggesting proper ECM deposition. Remarkably, differentiated cells exposed to TROPO acquired an elastogenic profile due to the evident elastin synthesis and deposition, contributing to the formation of a more mimetic matrix in comparison with the PDA-coated and uncoated conditions. In summary, our biomimetic substrates combining biophysical and biological cues modulate stem cell behavior potentiating their long-term tenogenic commitment and the production of an elastin-rich ECM.