Cooke Megan E, Rosenzweig Derek H
APL Bioeng. 2021 Feb 4;5(1):011502. doi: 10.1063/5.0031475. eCollection 2021 Mar.
Bioprinting is a tool increasingly used in tissue engineering laboratories around the world. As an extension to classic tissue engineering, it enables high levels of control over the spatial deposition of cells, materials, and other factors. It is a field with huge promise for the production of implantable tissues and even organs, but the availability of functional bioinks is a barrier to success. Extrusion bioprinting is the most commonly used technique, where high-viscosity solutions of materials and cells are required to ensure good shape fidelity of the printed tissue construct. This is contradictory to hydrogels used in tissue engineering, which are generally of low viscosity prior to cross-linking to ensure cell viability, making them not directly translatable to bioprinting. This review provides an overview of the important rheological parameters for bioinks and methods to assess printability, as well as the effect of bioink rheology on cell viability. Developments over the last five years in bioink formulations and the use of suspended printing to overcome rheological limitations are then discussed.
生物打印是一种在世界各地的组织工程实验室中越来越常用的工具。作为经典组织工程的延伸，它能够对细胞、材料和其他因素的空间沉积进行高度控制。这是一个在生产可植入组织甚至器官方面有着巨大前景的领域，但功能性生物墨水的可用性是成功的一个障碍。挤出式生物打印是最常用的技术，在这种技术中，需要高粘度的材料和细胞溶液来确保打印组织构建体具有良好的形状保真度。这与组织工程中使用的水凝胶相矛盾，水凝胶在交联之前通常粘度较低以确保细胞活力，这使得它们不能直接用于生物打印。本综述概述了生物墨水的重要流变学参数、评估可打印性的方法以及生物墨水流变学对细胞活力的影响。然后讨论了过去五年生物墨水配方的发展以及使用悬浮打印来克服流变学限制的情况。
