Korea Artificial Organ Center, College of Medicine, Korea University, Seoul, Korea.
Artif Organs. 2011 Nov;35(11):1132-6. doi: 10.1111/j.1525-1594.2011.01377.x.
Bioprinting is a technology for constructing bioartificial tissue or organs of complex three-dimensional (3-D) structure with high-precision spatial shape forming ability in larger scale than conventional tissue engineering methods and simultaneous multiple components composition ability. It utilizes computer-controlled 3-D printer mechanism or solid free-form fabrication technologies. In this study, sodium alginate hydrogel that can be utilized for large-dimension tissue fabrication with its fast gelation property was studied regarding material-specific printing technique and printing parameters using a multinozzle bioprinting system developed by the authors. A sodium alginate solution was prepared with a concentration of 1% (wt/vol), and 1% CaCl(2) solution was used as cross-linker for the gelation. The two materials were loaded in each of two nozzles in the multinozzle bioprinting system that has a total of four nozzles of which the injection speed can be independently controlled. A 3-D alginate structure was fabricated through layer-by-layer printing. Each layer was formed through two phases of printing, the first phase with the sodium alginate solution and the second phase with the calcium chloride solution, in identical printing pattern and speed condition. The target patterns were lattice shaped with 2-mm spacing and two different line widths. The nozzle moving speed was 6.67 mm/s, and the injection head speed was 10 µm/s. For the two different line widths, two injection needles with inner diameters of 260 and 410 µm were used. The number of layers accumulated was five in this experiment. By varying the nozzle moving speed and the injection speed, various pattern widths could be achieved. The feasibility of sodium alginate hydrogel free-form formation by alternate printing of alginate solution and sodium chloride solution was confirmed in the developed multinozzle bioprinting system.
生物打印是一种构建具有高精度空间形状形成能力的复杂三维（3-D）结构的生物人工组织或器官的技术，其规模大于传统的组织工程方法，并且具有同时组合多种成分的能力。它利用计算机控制的 3-D 打印机机制或立体光固化成型技术。在这项研究中，研究了具有快速凝胶特性的海藻酸钠水凝胶，可用于大尺寸组织制造，针对特定材料的打印技术和打印参数，使用作者开发的多喷嘴生物打印系统。将浓度为 1%（重量/体积）的海藻酸钠溶液制备成溶液，并将 1%的氯化钙溶液用作凝胶的交联剂。将两种材料分别装入多喷嘴生物打印系统的两个喷嘴中，该系统共有四个喷嘴，可独立控制其注射速度。通过逐层打印来制造 3-D 海藻酸盐结构。每层由两个阶段的打印形成，第一阶段使用海藻酸钠溶液，第二阶段使用氯化钙溶液，在相同的打印图案和速度条件下进行。目标图案是具有 2-mm 间距和两种不同线宽的晶格形状。喷嘴移动速度为 6.67 mm/s，注射头速度为 10 µm/s。对于两种不同的线宽，使用内径为 260 和 410 µm 的两个注射针。在本实验中，累积的层数为 5 层。通过改变喷嘴移动速度和注射速度，可以实现各种图案宽度。在开发的多喷嘴生物打印系统中，通过交替打印海藻酸钠溶液和氯化钠溶液，证实了海藻酸钠水凝胶自由形态形成的可行性。
