Singapore Center for 3D Printing and ‡School of Mechanical and Aerospace Engineering, Nanyang Technological University , 50 Nanyang Avenue, 639798 Singapore.
ACS Appl Mater Interfaces. 2017 Jun 14;9(23):20086-20097. doi: 10.1021/acsami.7b04216. Epub 2017 Jun 5.
A robust alginate/methylcellulose (Alg/MC) blend hydrogel, with a strategy to improve adhesion between printed layers, has been fabricated for the first time for three-dimensional (3D) bioprinting. The optimized Alg/MC blend hydrogel exhibits a highly thixotropic property, great extrudability, and stackability. With treatment by a trisodium citrate (TSC) solution, the interfacial bonding between the printed layers is significantly improved. The TSC solution acts as a chelating agent to remove the superficial calcium ions at each layer. Post-cross-linking in a CaCl bath after 3D printing further enhances the adhesion strength between the layers. The key parameters affecting the interfacial strength of the Alg/MC hydrogel are found to be the concentration of TSC, the volume of TSC, and the concentration of CaCl in the bath. The Alg/MC hydrogel with the aid of TSC demonstrates superior printability, high stackability (150 layers can be printed), and high shape fidelity. A good cell viability of >95% is obtained for a freshly 3D-bioprinted Alg/MC construct. The novel Alg/MC hydrogel with the aid of TSC has been shown to have a great potential as an advanced 3D bioprinting material.
一种稳健的海藻酸盐/甲基纤维素（Alg/MC）混合水凝胶，采用一种提高打印层之间附着力的策略，首次被用于三维（3D）生物打印。优化的 Alg/MC 混合水凝胶表现出高度触变性、出色的可挤出性和可堆叠性。经三钠柠檬酸（TSC）溶液处理后，打印层之间的界面结合得到显著改善。TSC 溶液作为螯合剂，去除每层表面的钙离子。3D 打印后在 CaCl 浴中进行后交联进一步增强了层间的附着强度。发现影响 Alg/MC 水凝胶界面强度的关键参数是 TSC 的浓度、TSC 的体积以及浴中 CaCl 的浓度。在 TSC 的辅助下，Alg/MC 水凝胶具有出色的可打印性、高可堆叠性（可打印 150 层）和高形状保真度。新的 3D 生物打印 Alg/MC 结构的细胞活力>95%。具有 TSC 辅助作用的新型 Alg/MC 水凝胶具有作为先进的 3D 生物打印材料的巨大潜力。
