Hydrogels comprised of alginate and gelatin have demonstrated potential as biomaterials in three dimensional (3D) bioprinting applications. However, as with all hydrogel-based biomaterials used in extrusion-based bioprinting, many parameters influence their performance and there is limited data characterising the behaviour of alginate-gelatin (Alg-Gel) hydrogels.

Here we investigated nine Alg-Gel blends by varying the individual constituent concentrations. We tested samples for printability and print accuracy, compressive behaviour and change over time, and viability of encapsulated mesenchymal stem cells in bioprinted constructs.

Printability tests showed a decrease in strand width with increasing concentrations of Alg-Gel. However due to the increased viscosity associated with the higher Alg-Gel concentrations, the minimum width was found to be 0.32 mm before blends became too viscous to print. Similarly, printing accuracy was increased in higher concentrations, exceeding 90% in some blends. Mechanical properties were assessed through uniaxial compression testing and it was found that increasing concentrations of both Alg and Gel resulted in higher compressive modulus. We also deemed 15 min crosslinking in calcium chloride to be sufficient. From our data, we propose a blend of 7%Alg-8%Gel that yields high printability, mechanical strength and stiffness, and cell viability. However, we found the compressive behaviour of Alg-Gel to reduce rapidly over time and especially when incubated at 37 °C.

Here we have reported relevant data on Alg-Gel hydrogels for bioprinting. We tested for biomaterial properties and show that these hydrogels have many desirable characteristics that are highly tunable. Though further work is needed before practical use in vivo can be achieved.

由藻酸盐和明胶组成的水凝胶已显示出在三维（3D）生物打印应用中作为生物材料的潜力。但是，与基于挤出的生物打印中使用的所有基于水凝胶的生物材料一样，许多参数会影响其性能，并且表征藻酸盐-明胶（Alg-Gel）水凝胶行为的数据有限。

在这里，我们通过改变各个成分的浓度研究了九种Alg-Gel共混物。我们测试了样品的可印刷性和印刷准确性，压缩行为和随时间的变化以及生物印刷结构中封装的间充质干细胞的生存能力。

适印性测试表明，随着Alg-Gel浓度的增加，线宽减小。然而，由于与较高的Alg-Gel浓度相关的粘度增加，在共混物变得太粘而无法印刷之前，发现最小宽度为0.32 mm。同样，在更高的浓度下，打印精度也有所提高，在某些混合物中，超过90％。通过单轴压缩试验评估机械性能，发现增加Alg和Gel的浓度会导致较高的压缩模量。我们还认为在氯化钙中15分钟交联就足够了。根据我们的数据，我们提出了7％Alg-8％Gel的混合物，可产生高印刷性，机械强度和刚度以及细胞活力。然而，

在这里，我们已经报道了用于生物印刷的Alg-Gel水凝胶的相关数据。我们测试了生物材料的性能，并表明这些水凝胶具有许多可调节的理想特性。尽管需要进一步的工作才能实现体内的实际应用。