Both of the long-term fidelity and cell viability of three-dimensional (3D)-bioprinted constructs are essential to precise soft tissue repair. However, the shrinking/swelling behavior of hydrogels brings about inadequate long-term fidelity of constructs, and bioinks containing excessive polymer are detrimental to cell viability. Here, we obtained a facile hydrogel by introducing 1% aldehyde hyaluronic acid (AHA) and 0.375% N-carboxymethyl chitosan (CMC), two polysaccharides with strong water absorption and water retention capacity, into classic gelatin (GEL, 5%)–alginate (ALG, 1%) ink. This GEL–ALG/CMC/AHA bioink possesses weak temperature dependence due to the Schiff base linkage of CMC/AHA and electrostatic interaction of CMC/ALG. We fabricated integrated constructs through traditional printing at room temperature and in vivo simulation printing at 37°C. The printed cell-laden constructs can maintain subaqueous fidelity for 30 days after being reinforced by 3% calcium chloride for only 20 s. Flow cytometry results showed that the cell viability was 91.38 ± 1.55% on day 29, and the cells in the proliferation plateau at this time still maintained their dynamic renewal with a DNA replication rate of 6.06 ± 1.24%. This work provides a convenient and practical bioink option for 3D bioprinting in precise soft tissue repair.

中文翻译：

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用于 3D 生物打印的简便、多功能水凝胶生物墨水有利于长期水下保真度、细胞活力和增殖

三维 (3D) 生物打印结构的长期保真度和细胞活力对于精确的软组织修复至关重要。然而，水凝胶的收缩/膨胀行为会导致结构的长期保真度不足，并且含有过量聚合物的生物墨水不利于细胞活力。在这里，我们通过将 1% 醛基透明质酸 (AHA) 和 0.375% N-羧甲基壳聚糖 (CMC) 这两种具有强吸水和保水能力的多糖引入经典明胶 (GEL, 5%)-藻酸盐中，获得了一种简便的水凝胶。 (ALG, 1%) 墨水。由于 CMC/AHA 的席夫碱键和 CMC/ALG 的静电相互作用，这种 GEL-ALG/CMC/AHA 生物墨水具有较弱的温度依赖性。我们通过在室温下的传统打印和在 37°C 的体内模拟打印来制造集成结构。打印的载有细胞的结构在用 3% 的氯化钙加固 20 秒后，可以在水下保持 30 天。流式细胞仪结果显示，第29天细胞活力为91.38±1.55%，此时处于增殖平台的细胞仍保持动态更新，DNA复制率为6.06±1.24%。这项工作为精确软组织修复中的 3D 生物打印提供了一种方便实用的生物墨水选择。此时处于增殖平台的细胞仍保持动态更新，DNA复制率为6.06±1.24%。这项工作为精确软组织修复中的 3D 生物打印提供了一种方便实用的生物墨水选择。此时处于增殖平台的细胞仍保持动态更新，DNA复制率为6.06±1.24%。这项工作为精确软组织修复中的 3D 生物打印提供了一种方便实用的生物墨水选择。