Recently, decellularized extracellular matrix-based bio-ink (dECM bio-ink) derived from animal organs is attracting attention because of its excellent biocompatibility. However, its poor 3D printability and weak mechanical properties remain a challenge. Here, we developed a new dECM bio-ink with enhanced 3D printability and mechanical properties. dECM micro-particles of about 13.4 μm in size were prepared by decellularizing a porcine liver followed by freeze-milling. The new bio-ink, named as dECM powder-based bio-ink (dECM pBio-ink), was prepared by loading the dECM micro-particles into a gelatin mixture. The usefulness of the dECM pBio-ink was evaluated by assessing its mechanical properties, printability, and cytocompatibility. The results showed that its mechanical properties and 3D printability were greatly improved. Its elastic modulus increased by up to 9.17 times that of the conventional dECM bio-ink. Micro-patterns with living cells were successfully achieved with 93% cell viability. Above all, the new bio-ink showed superior performance in stacking of layers for 3D printing, whereas the conventional bio-ink could not maintain its shape. Finally, we demonstrated that the dECM pBio-ink possessed comparable cytocompatibility with the conventional dECM bio-ink through in vitro tests with endothelial cells and primary mouse hepatocytes.

中文翻译：

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脱细胞的基于细胞外基质的生物墨水，具有增强的3D可打印性和机械性能。

近年来，源自动物器官的脱细胞的基于细胞外基质的生物墨水（dECM生物墨水）因其出色的生物相容性而受到关注。然而，其较差的3D可打印性和较弱的机械性能仍然是一个挑战。在这里，我们开发了一种新型的dECM生物墨水，该墨水具有增强的3D可打印性和机械性能。通过使猪肝脱细胞，然后进行冷冻研磨，制备尺寸为约13.4μm的dECM微粒。通过将dECM微粒装入明胶混合物中来制备新的生物墨水，称为基于dECM粉末的生物墨水（dECM pBio-ink）。通过评估dECM pBio墨水的机械性能，可印刷性和细胞相容性来评估其实用性。结果表明，其机械性能和3D可印刷性得到了极大的改善。其弹性模量增加了传统dECM生物墨水的9.17倍。具有活细胞的微模式已成功实现，细胞活力为93％。最重要的是，新的生物墨水在3D打印的层堆叠中显示出卓越的性能，而传统的生物墨水无法保持其形状。最后，我们通过内皮细胞和原代小鼠肝细胞的体外测试证明了dECM pBio-ink具有与传统dECM生物墨水相当的细胞相容性。