Fu Jiayin, Chuah Yon Jin, Ang Wee Tong, Zheng Nan, Wang Dong-An
Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457.
Biomater Sci. 2017 May 30;5(6):1156-1173. doi: 10.1039/c7bm00266a.
Myocardiocyte derived from pluripotent stem cells, such as induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs), is a promising cell source for cardiac tissue engineering. Combined with microfluidic technologies, a heart-on-a-chip is very likely to be developed and function as a platform for high throughput drug screening. Polydimethylsiloxane (PDMS) silicone elastomer is a widely-used biomaterial for the investigation of cell-substrate interactions and biochip fabrication. However, the intrinsic PDMS surface hydrophobicity inhibits cell adhesion on the PDMS surface, and PDMS surface modification is required for effective cell adhesion. Meanwhile, the formulation of PDMS also affects the behaviors of the cells. To fabricate PDMS-based biochips for ESC pluripotency maintenance and cardiac differentiation, PDMS surface modification and formulation were optimized in this study. We found that a polydopamine (PD) with gelatin coating greatly improved the ESC adhesion, proliferation and cardiac differentiation on its surface. In addition, different PDMS substrates varied in their surface properties, which had different impacts on ESCs, with the 40 : 1 PDMS substrate being more favorable for ESC adhesion and proliferation as well as embryoid body (EB) attachment than the other PDMS substrates. Moreover, the ESC pluripotency was best maintained on the 5 : 1 PDMS substrate, while the cardiac differentiation of the ESCs was optimal on the 40 : 1 PDMS substrate. Based on the optimized coating method and PDMS formulation, biochips with two different designs were fabricated and evaluated. Compared to the single channels, the multiple channels on the biochips could provide larger areas and accommodate more nutrients to support improved ESC pluripotency maintenance and cardiac differentiation. These results may contribute to the development of a real heart-on-a-chip for high-throughput drug screening in the future.
源自多能干细胞（如诱导多能干细胞（iPSC）和胚胎干细胞（ESC））的心肌细胞是心脏组织工程中一种很有前景的细胞来源。与微流控技术相结合，很有可能开发出芯片心脏并将其用作高通量药物筛选的平台。聚二甲基硅氧烷（PDMS）硅橡胶是一种广泛用于研究细胞与基质相互作用及生物芯片制造的生物材料。然而，PDMS固有的表面疏水性会抑制细胞在PDMS表面的黏附，因此需要对PDMS表面进行改性以实现有效的细胞黏附。同时，PDMS的配方也会影响细胞的行为。在本研究中，为制备用于ESC多能性维持和心脏分化的基于PDMS的生物芯片，对PDMS表面改性和配方进行了优化。我们发现，涂有明胶的聚多巴胺（PD）极大地改善了ESC在其表面的黏附、增殖和心脏分化。此外，不同的PDMS底物表面性质不同，对ESC的影响也不同，40∶1的PDMS底物比其他PDMS底物更有利于ESC的黏附、增殖以及胚状体（EB）的附着。此外，ESC多能性在5∶1的PDMS底物上维持得最好，而ESC的心脏分化在40∶1的PDMS底物上最为理想。基于优化的涂层方法和PDMS配方，制备并评估了两种不同设计的生物芯片。与单通道相比，生物芯片上的多通道可以提供更大的面积并容纳更多营养物质，以支持改善ESC多能性维持和心脏分化。这些结果可能有助于未来开发用于高通量药物筛选的真正的芯片心脏。
