Abstract：
Silk fibroin (SF) is a natural protein extracted fromBombyx morisilkworm thread. From its common use in the textile industry, it emerged as a biomaterial with promising biochemical and mechanical properties for applications in the field of tissue engineering and regenerative medicine. In this study, we evaluate for the first time the effects of SF on cardiac bioink formulations containing cardiac spheroids (CSs). First, we evaluate if the SF addition plays a role in the structural and elastic properties of hydrogels containing alginate (Alg) and gelatin (Gel). Then, we test the printability and durability of bioprinted SF-containing hydrogels. Finally, we evaluate whether the addition of SF controls cell viability and function of CSs in Alg-Gel hydrogels. Our findings show that the addition of 1% (w/v) SF to Alg-Gel hydrogels makes them more elastic without affecting cell viability. However, fractional shortening (FS%) of CSs in SF-Alg-Gel hydrogels increases without affecting their contraction frequency, suggesting an improvement in contractile function in the 3D cultures. Altogether, our findings support a promising pathway to bioengineer bioinks containing SF for cardiac applications, with the ability to control mechanical and cellular features in cardiac bioinks.
摘要：
丝素蛋白（SF）是从家蚕丝线中提取的天然蛋白质。从其在纺织工业中的普遍使用来看，它是一种生物材料，具有有前途的生化和机械性能，可应用于组织工程和再生医学领域。在这项研究中,我们首次评估了SF对含有心脏球体的心脏生物墨水制剂的影响。首先,我们评估SF添加是否在含有藻酸盐（Alg）和明胶（Gel）的水凝胶的结构和弹性特性中起作用。然后，我们测试生物打印的含SF水凝胶的可印刷性和耐久性。最后,我们评估了在Alg-Gel水凝胶中添加SF是否可以控制细胞活力和心脏球体的功能。我们的发现表明，向Alg-Gel水凝胶中添加1％（w/v）SF会使它们更具弹性，而不会影响细胞活力。然而,SF-Alg-Gel水凝胶中心脏球体的缩短分数（FS％）增加而不影响其收缩频率，表明3D培养物中收缩功能的改善。总之,我们的发现支持了一个有希望的途径，将含有SF的生物墨水用于心脏应用，具有控制心脏生物墨水的机械和细胞特征的能力。
