Coaxial nozzle-assisted 3D bioprinting with built-in microchannels for nutrients delivery
Coaxial nozzle-assisted 3D bioprinting with built-in microchannels for nutrients delivery
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DOI：
10.1016/j.biomaterials.2015.05.031
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发表时间：
2015-08-01
期刊：
影响因子：
14
通讯作者：
Ma, Liang
中科院分区：
文献类型：
--
作者：
Gao, Qing;He, Yong;Ma, Liang
本研究提出了一种利用同轴喷嘴对海藻酸钙中空纤维进行三维生物打印的新方法，该方法通过控制交联时间来实现相邻中空纤维的融合，从而形成具有内嵌微通道的高强度水凝胶三维结构。利用Z形平台的三维生物打印系统实现了细胞水凝胶结构的层层制备。通过改变长丝挤出速度或平台移动速度，可以形成弯曲、直、拉伸或断裂的长丝。为了打印三维结构，我们首先在交联过程中调整海藻酸钠和氯化钙溶液的浓度和流量，得到部分交联的长丝。然后，使用带有同轴喷嘴的电动XY工作台来控制邻近的中空丝在熔化的精确位置沉积。然后，连接有Z形平台的Z工作台顺序向下移动，以打印结构层。在印刷过程中，始终保持上两层熔合，下两层固化。最后，Z阶段下移以保持印刷结构浸泡在CaCl2溶液中以实现完全交联。对所得到的融合结构的力学性能进行了研究。使用较高浓度的海藻酸钠溶液和较小的相邻中空纤维之间的距离可以形成高强度结构。此外，对该方法的细胞活力进行了研究，结果表明，L929小鼠成纤维细胞在中空结构中的细胞活力高于在没有内置微通道的藻酸盐结构中的细胞活力。与其他生物打印方法相比，这项研究是一项重要的技术，可以方便地制造具有内置微通道的大型器官。(C)2015爱思唯尔有限公司。保留所有权利。
This study offers a novel 3D bioprinting method based on hollow calcium alginate filaments by using a coaxial nozzle, in which high strength cell-laden hydrogel 3D structures with built-in microchannels can be fabricated by controlling the crosslinking time to realize fusion of adjacent hollow filaments. A 3D bioprinting system with a Z-shape platform was used to realize layer-by-layer fabrication of cell-laden hydrogel structures. Curving, straight, stretched or fractured filaments can be formed by changes to the filament extrusion speed or the platform movement speed. To print a 3D structure, we first adjusted the concentration and flow rate of the sodium alginate and calcium chloride solution in the crosslinking process to get partially crosslinked filaments. Next, a motorized XY stages with the coaxial nozzle attached was used to control adjacent hollow filament deposition in the precise location for fusion. Then the Z stage attached with a Z-shape platform moved down sequentially to print layers of structure. And the printing process always kept the top two layers fusing and the below layers solidifying. Finally, the Z stage moved down to keep the printed structure immersed in the CaCl2 solution for complete crosslinking. The mechanical properties of the resulting fused structures were investigated. High-strength structures can be formed using higher concentrations of sodium alginate solution with smaller distance between adjacent hollow filaments. In addition, cell viability of this method was investigated, and the findings show that the viability of L929 mouse fibroblasts in the hollow constructs was higher than that in alginate structures without built-in microchannels. Compared with other bioprinting methods, this study is an important technique to allow easy fabrication of lager-scale organs with built-in microchannels. (C) 2015 Elsevier Ltd. All rights reserved.