Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
Biofabrication. 2017 Jul 25;9(3):034103. doi: 10.1088/1758-5090/aa7e96.
Three-dimensional printing of cell-laden hydrogels has evolved as a promising approach on the route to patient-specific or complex tissue-engineered constructs. However, it is still challenging to print structures with both, high shape fidelity and cell vitality. Herein, we used a synthetic nanosilicate clay, called Laponite, to build up scaffolds utilising the extrusion-based method 3D plotting. By blending with alginate and methylcellulose, a bioink was developed which allowed easy extrusion, achieving scaffolds with high printing fidelity. Following extrusion, approximately 70%-75% of printed immortalised human mesenchymal stem cells survived and cell viability was maintained over 21 days within the plotted constructs. Mechanical properties of scaffolds comprised of the composite bioink decreased over time when stored under cell culture conditions. Nevertheless, shape of the plotted constructs was preserved even over longer cultivation periods. Laponite is known for its favourable drug delivery properties. Two model proteins, bovine serum albumin and vascular endothelial growth factor were loaded into the bioink. We demonstrate that the release of both growth factors significantly changed to a more sustained profile by inclusion of Laponite in comparison to an alginate-methylcellulose blend in the absence of Laponite. In summary, addition of a synthetic clay, Laponite, improved printability, increased shape fidelity and was beneficial for controlled release of biologically active agents such as growth factors.
三维打印细胞水凝胶已成为一种很有前途的方法，可用于制造患者特异性或复杂的组织工程构建体。然而，要打印出具有高形状保真度和细胞活力的结构仍然具有挑战性。在此，我们使用了一种名为 Laponite 的合成纳米硅酸盐粘土，利用基于挤出的 3D 绘图方法构建支架。通过与藻酸盐和甲基纤维素混合，开发了一种生物墨水，可实现轻松挤出，从而获得具有高打印保真度的支架。挤出后，大约 70%-75%的打印永生化人间充质干细胞存活下来，并且在绘制的构建体中保持细胞活力超过 21 天。在细胞培养条件下储存时，由复合生物墨水组成的支架的机械性能随时间的推移而降低。尽管如此，即使在更长的培养时间内，绘制的构建体的形状也得以保持。Laponite 以其有利的药物输送性能而闻名。两种模型蛋白，牛血清白蛋白和血管内皮生长因子被加载到生物墨水中。我们证明，与不含 Laponite 的藻酸盐-甲基纤维素混合物相比，将 Laponite 加入生物墨水中可显著改变释放曲线，使其更具持续性。总之，添加合成粘土 Laponite 可提高可打印性、增加形状保真度，并有利于生物活性药物如生长因子的控制释放。
