Heart valve tissue engineering could be an alternative to the current bioprosthetic heart valve that faces limitations especially in pediatric patients. However, heart valve tissue engineering has remained challenging because leaflets - the primary component of a heart valve - have three layers with three diverse orientations - circumferential, random and radial, respectively. In order to mimic the orientations, we first designed three novel collectors to fabricate three nanofibrous layers with those orientations from a polymeric biomaterial in an electrospinning system. Then, we devised a novel direct electrospinning technique to develop a unified trilayered nanofibrous (TN) substrate comprising those oriented layers. The TN substrate supported the growth and orientations of seeded porcine valvular interstitial cells (PVICs) and their deposited collagen fibrils. After one month culture, the obtained trilayered tissue construct (TC) exhibited increased tensile properties over its TN substrate. Most importantly, the developed TC did not show any sign of shrinkage. Gene expression pattern of the PVICs indicated the developing stage of the TC. Their protein expression pattern was quite similar to that of leaflets. STATEMENT OF SIGNIFICANCE: This manuscript talks about development of a novel trilayered nanofibrous substrate mimicking the morphologies of a heart valve leaflet. It also describes culturing of valvular interstitial cells that reside in a leaflet, in the substrate and compares the behavior of the cultured cells with that in native leaflets in terms cell morphology, protein deposition and its orientation, and molecular signature. This study builds the groundwork for our future trilayered, tissue-engineered leaflet development. This research article would be of great interest to investigators and researchers in the field of cardiovascular tissue engineering especially in cardiac valve tissue engineering through biomaterial-based tissue engineering.

中文翻译：

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模仿心脏瓣膜小叶形态的三层纳米纤维基质上瓣膜间质细胞的行为。

心脏瓣膜组织工程可能是当前生物假体心脏瓣膜的替代方案，目前生物假体心脏瓣膜面临着局限性，尤其是在儿科患者中。然而，心脏瓣膜组织工程仍然具有挑战性，因为小叶（心脏瓣膜的主要组成部分）具有三个不同方向的三层：分别为圆周、随机和径向。为了模仿这些方向，我们首先设计了三种新颖的收集器，以在静电纺丝系统中用聚合生物材料制造具有这些方向的三个纳米纤维层。然后，我们设计了一种新颖的直接静电纺丝技术来开发包含这些定向层的统一三层纳米纤维（TN）基材。TN 基质支持接种的猪瓣膜间质细胞 (PVIC) 及其沉积的胶原纤维的生长和方向。培养一个月后，获得的三层组织构建体 (TC) 表现出比 TN 基底更高的拉伸性能。最重要的是，开发出来的TC并没有出现任何收缩的迹象。PVIC 的基因表达模式表明了 TC 的发育阶段。它们的蛋白质表达模式与传单非常相似。意义声明：这篇手稿讨论了一种模仿心脏瓣膜小叶形态的新型三层纳米纤维基材的开发。它还描述了驻留在小叶、基质中的瓣膜间质细胞的培养，并将培养细胞的行为与天然小叶中的细胞形态、蛋白质沉积及其方向以及分子特征进行比较。这项研究为我们未来的三层组织工程传单开发奠定了基础。这篇研究文章将引起心血管组织工程领域的研究者和研究人员的极大兴趣，特别是通过基于生物材料的组织工程进行心脏瓣膜组织工程。