Institute of Biomaterials, University of Erlangen-Nuremberg, Cauerstr.6, 91058, Erlangen, Germany.
Biofabrication. 2020 Jul 9;12(4):045004. doi: 10.1088/1758-5090/ab98e5.
Many different biofabrication approaches as well as a variety of bioinks have been developed by researchers working in the field of tissue engineering. A main challenge for bioinks often remains the difficulty to achieve shape fidelity after printing. In order to overcome this issue, a homogeneous pre-crosslinking technique, which is universally applicable to all alginate-based materials, was developed. In this study, the Young's Modulus after post-crosslinking of selected hydrogels, as well as the chemical characterization of alginate in terms of M/G ratio and molecular weight, were determined. With our technique it was possible to markedly enhance the printability of a 2% (w/v) alginate solution, without using a higher polymer content, fillers or support structures. 3D porous scaffolds with a height of around 5 mm were printed. Furthermore, the rheological behavior of different pre-crosslinking degrees was studied. Shear forces on cells as well as the flow profile of the bioink inside the printing nozzle during the process were estimated. A high cell viability of printed NIH/3T3 cells embedded in the novel bioink of more than 85% over a time period of two weeks could be observed.
许多不同的生物制造方法以及各种各样的生物墨水已经被从事组织工程领域的研究人员开发出来。生物墨水的一个主要挑战通常仍然是打印后难以实现形状保真度。为了克服这个问题，开发了一种通用的预交联技术，该技术普遍适用于所有基于海藻酸盐的材料。在这项研究中，确定了所选水凝胶在交联后的杨氏模量，以及海藻酸盐的化学特性，包括 M/G 比和分子量。使用我们的技术，有可能显著提高 2%（w/v）海藻酸盐溶液的可打印性，而无需使用更高的聚合物含量、填充剂或支撑结构。打印出高度约为 5 毫米的 3D 多孔支架。此外，还研究了不同预交联程度的流变行为。估计了细胞上的剪切力以及在打印过程中生物墨水在打印喷嘴内的流动情况。在两周的时间内，嵌入新型生物墨水中的打印 NIH/3T3 细胞的细胞活力超过 85%。
