You Yuru, Xu Feng, Liu Lingling, Chen Songyue, Ding Zhengmao, Sun Daoheng
Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361000, China.
Polymers (Basel). 2024 Sep 22;16(18):2664. doi: 10.3390/polym16182664.
A major challenge in myocardial tissue engineering is replicating the heart's highly complex three-dimensional (3D) anisotropic structure. Heart-on-a-chip (HOC) is an emerging technology for constructing myocardial tissue in vitro in recent years, but most existing HOC systems face difficulties in constructing 3D myocardial tissue aligned with multiple cell layers. Electrospun nanofibers are commonly used as scaffolds for cell growth in myocardial tissue engineering, which can structurally simulate the extracellular matrix to induce the aligned growth of myocardial cells. Here, we developed an HOC that integrates multi-layered aligned polycaprolactone (PCL) nanofiber scaffolds inside microfluidic chips, and constructed 3D thick and aligned tissue with a layered seeding approach. By culturing human-induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs) on chip, the myocardial tissue on the two layered nanofibers reached a thickness of ~53 μm compared with ~19 μm for single-layered nanofibers. The obtained myocardial tissue presented well-aligned structures, with densely distributed α-actinin. By the third day post seeding, the hiPSC-CMs contract highly synchronously, with a contraction frequency of 18 times/min. The HOC with multi-layered biomimetic scaffolds provided a dynamic in vitro culture environment for hiPSC-CMs. Together with the layered cell-seeding process, the designed HOC promoted the formation of thick, well-aligned myocardial tissue.
心肌组织工程中的一个主要挑战是复制心脏高度复杂的三维（3D）各向异性结构。芯片心脏（HOC）是近年来体外构建心肌组织的一项新兴技术，但大多数现有的HOC系统在构建具有多层细胞层排列的3D心肌组织方面面临困难。电纺纳米纤维通常用作心肌组织工程中细胞生长的支架，其可以在结构上模拟细胞外基质以诱导心肌细胞的排列生长。在此，我们开发了一种在微流控芯片内部集成多层排列的聚己内酯（PCL）纳米纤维支架的HOC，并采用分层接种方法构建了3D厚且排列整齐的组织。通过在芯片上培养人诱导多能干细胞衍生的心肌细胞（hiPSC-CM），与单层纳米纤维相比，两层纳米纤维上的心肌组织厚度达到约53μm，而单层纳米纤维的厚度约为19μm。所获得的心肌组织呈现出排列良好的结构，α-辅肌动蛋白分布密集。接种后第三天，hiPSC-CM高度同步收缩，收缩频率为18次/分钟。具有多层仿生支架的HOC为hiPSC-CM提供了动态的体外培养环境。与分层细胞接种过程一起，所设计的HOC促进了厚且排列良好的心肌组织的形成。
