Three-dimensional (3D) printing is a promising method to prepare scaffolds for tissue regeneration. Collagen and chitosan composites are superior materials for tissue engineering scaffold but rarely printed due to their poor printability. Here, we prepared a series of tunable hybrid collagen/chitosan bioinks with significantly improved printability through hydrogen bond interaction and printed them into scaffolds by carefully controlling the temperature. Rheological tests proved the printable bioinks had sound shear thinning behavior, dramatical viscosity variation with temperature, and the gelation temperature from 7 to 10 °C. Chitosan could decrease the swelling ratio of the printed scaffolds, while their degradation rate increased with collagen proportion and the values of Young's modulus and tensile strength increased with chitosan proportion. Moreover, the scaffolds containing 2% (m/v) collagen and 2% (m/v) chitosan had a homogeneous and compact honeycomb-like structure, demonstrating the strengthening effect of chitosan. Cell viability assay presented vigorous cell growth on the surface of scaffolds, meanwhile, live cells were also found inside and at the bottom of the scaffolds, indicating the migration of cells. Therefore, chitosan can improve the printability of collagen and the hybrid collagen/chitosan bioinks can be printed into scaffolds with regulated properties, thus can fit different applications in tissue engineering.

三维（3D）打印是一种制备组织再生支架的有前途的方法。胶原蛋白和壳聚糖复合材料是用于组织工程支架的优质材料，但由于其可印刷性差而很少印刷。在这里，我们制备了一系列可调的胶原蛋白/壳聚糖杂化生物墨水，通过氢键相互作用显着改善了可印刷性，并通过仔细控制温度将它们印刷到支架中。流变学试验证明可印刷的生物油墨具有良好的剪切稀化行为，粘度随温度急剧变化，并且胶凝温度为7至10°C。壳聚糖可以降低印刷支架的溶胀率，而降解速率则随胶原比例和Young'值的增加而增加。s模量和拉伸强度随壳聚糖比例的增加而增加。而且，含有2％（m / v）胶原蛋白和2％（m / v）壳聚糖的支架具有均匀且致密的蜂窝状结构，证明了壳聚糖的增强作用。细胞生存力测定显示了支架表面上的旺盛细胞生长，同时，在支架内部和底部也发现了活细胞，表明细胞迁移。因此，壳聚糖可以改善胶原蛋白的可印刷性，并且可以将混合的胶原蛋白/壳聚糖生物油墨印刷到具有调节特性的支架中，从而可以适合组织工程中的不同应用。细胞生存力测定显示了支架表面上的旺盛细胞生长，同时，在支架内部和底部也发现了活细胞，表明细胞迁移。因此，壳聚糖可以改善胶原蛋白的可印刷性，并且可以将混合的胶原蛋白/壳聚糖生物油墨印刷到具有调节特性的支架中，从而可以适合组织工程中的不同应用。细胞生存力测定显示了支架表面上的旺盛细胞生长，同时，在支架内部和底部也发现了活细胞，表明细胞迁移。因此，壳聚糖可以改善胶原蛋白的可印刷性，并且可以将混合的胶原蛋白/壳聚糖生物油墨印刷到具有调节特性的支架中，从而可以适合组织工程中的不同应用。