The study aims to investigate a novel bioink made from Chitosan (Cs)/ poly(gamma‐glutamic acid) (Gamma‐PGA) hydrogel that takes advantage of the two biodegradable and biocompatible polymers meeting most of the requirements for biomedical applications. The bioink could be an alternative to other materials commonly used in 3D‐bioprinting such as gelatin or alginate. Cs/ Gamma‐PGA hydrogel was prepared by double extrusion of Gamma‐PGA and Cs solutions, where 2 × 10⁵ human adult fibroblasts per ml Cs solution had been loaded, through Cellink 3D‐Bioprinter at 37°C. A computer aided design model was used to get 3D‐bioprinting of a four layers grid hydrogel construct with 70% infill. Hydrogel characterization involved rheology, FTIR analysis, stability study (mass loss [ML], fluid uptake [FU]), and cell retaining ability into hydrogel. 3D‐bioprinted hydrogel gelation time resulted to be <60 s, hydrogel structure was maintained up to 36.79 Pa shear stress, FTIR analysis demonstrated Gamma‐PGA/Cs interpolyelectrolyte complex formation. The 3D‐bioprinted hydrogel was stable for 35 days (35% ML) in cell culture medium, with increasing FU. Cell loaded 3D‐bioprinted Cs 6% hydrogel was able to retain 70% of cells which survived to printing process and cell viability was maintained during 14 days incubation.

中文翻译：

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一种新型天然基聚（γ-谷氨酸）/壳聚糖生物墨水的初步研究。

该研究旨在研究一种由壳聚糖（Cs）/聚（γ-谷氨酸）（Gamma-PGA）水凝胶制成的新型生物墨水，它利用两种可生物降解和生物相容性聚合物满足生物医学应用的大部分要求。生物墨水可以替代 3D 生物打印中常用的其他材料，如明胶或藻酸盐。Cs/ Gamma-PGA 水凝胶通过 Gamma-PGA 和 Cs 溶液的双重挤压制备，其中 2 × 10 ⁵已通过 Celllink 3D-Bioprinter 在 37°C 下加载了每毫升 Cs 溶液中的成人成纤维细胞。使用计算机辅助设计模型对填充 70% 的四层网格水凝胶结构进行 3D 生物打印。水凝胶表征涉及流变学、FTIR 分析、稳定性研究（质量损失 [ML]、液体吸收 [FU]）和细胞在水凝胶中的保留能力。3D 生物打印的水凝胶凝胶时间小于 60 秒，水凝胶结构保持高达 36.79 Pa 的剪切应力，FTIR 分析表明 Gamma-PGA/Cs 互聚电解质复合物形成。3D 生物打印水凝胶在细胞培养基中稳定 35 天（35% ML），FU 增加。细胞负载的 3D 生物打印 Cs 6% 水凝胶能够保留 70% 的细胞，这些细胞在打印过程中存活下来，并且在 14 天的孵育期间保持细胞活力。