3D printed, mechanically tunable, composite sodium alginate, gelatin and Gum Arabic (SA-GEL-GA) scaffolds
3D printed, mechanically tunable, composite sodium alginate, gelatin and Gum Arabic (SA-GEL-GA) scaffolds
复制标题
DOI：
10.1016/j.bprint.2021.e00133
复制
发表时间：
2021-06-01
期刊：
影响因子：
--
通讯作者：
Gozen, B. Arda
中科院分区：
文献类型：
--
作者：
Amr, Mahmoud;Dykes, India;Gozen, B. Arda
生物模拟天然组织的机械性能是工程组织支架的关键要求之一，从而需要对这种支架的机械性能具有高水平控制的材料和制造工艺。为了解决这一需求，我们提出了一种由海藻酸钠（SA）、明胶（GEL）和阿拉伯胶（GA）组成的3D可打印复合水凝胶，在本文中称为SA-GEL-GA水凝胶，其机械性能可以通过调节其交联过程来控制。在这里，这三种成分的水溶液被用作生物墨水，以在基于温度控制的挤出打印过程中3D打印多孔支架。然后，3D打印支架通过多步方法交联，实现GEL的凝胶化，SA和GA的离子交联以及所有三种组分的共价交联。在这里，我们表明，SA-GEL-GA水凝胶的固有机械性能可以通过共价交联步骤的持续时间来控制。SA-GEL-GA生物油墨表现出高度温度依赖性流变学，在室温以下具有弹性固体状行为，在28 ℃以上具有粘塑性剪切稀化性质。使用冷却的构建板和加热的打印头，以250 μ π ι的细丝直径打印高分辨率支架，并从100 μ π ι直径的喷嘴挤出。这些支架的压缩弹性模量可以通过支架孔尺寸和共价交联步骤持续时间的组合效应调节到50-250 kPa范围。3D打印和交联支架在水中的含量超过其干重的500%，并且可以干燥并重新缠绕至其干重的400%以上。最后，我们的降解分析表明，增加共价交联持续时间导致降低长期的结构稳定性，由于机械故障的支架。这些结果表明，SA-GEL-GA水凝胶为制造具有仿生机械性能的可定制人工组织支架提供了令人兴奋的机会，特别是对于软组织。
Biomimicking the mechanical properties of native tissues is one of the key requirements of engineering tissue scaffolds, rendering a need for materials and manufacturing processes with a high level of control over the mechanical properties of such scaffolds. To address this need, we present a 3D printable, composite hydrogel consisting of sodium alginate (SA), gelatin (GEL) and gum Arabic (GA), referred to herein as SA-GEL-GA hydrogel, mechanical properties of which can be controlled through tuning its cross-linking process. Here, the aqueous solution of the three constituents is used as the bioink to 3D print porous scaffolds in a temperature-controlled extrusion-based printing process. 3D-printed scaffolds are then crosslinked through a multi-step approach, realizing the gelation of GEL, ionic crosslinking of SA and GA, and covalent cross-linking of all three components. Here, we show that the inherent mechanical properties of SA-GEL-GA hydrogels can be controlled through the duration of the covalent crosslinking step. SA-GEL-GA bioinks exhibit highly temperature-dependent rheology with elastic solid-like behavior below room temperature and a viscoplastic, shear thinning nature above 28 'C. Using a cooled build-plate and heated printhead, high resolution scaffolds were printed with filament diameter of 250 pm and extruded from a 100 pm diameter nozzle. The compressive elastic modulus of these scaffolds can be tuned to the 50-250 kPa range through the combined effect of the scaffold pores size and covalent crosslinking step duration. 3D printed and crosslinked scaffolds carry over 500% of their dry weight in water and can be dried and reswollen to over 400% of their dry weight. Finally, our degradation analysis showed that increased covalent cross-linking duration led to reduced long-term structural stability due to mechanical failure of the scaffolds. These results indicate that SA-GEL-GA hydrogels offer exciting opportunities for manufacturing customizable artificial tissue scaffolds with biomimicking mechanical properties, particularly for soft tissues.