Singapore Centre for 3D Printing (SC3DP), Mechanical and Aerospace Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore 639798, Singapore.
J R Soc Interface. 2020 Jul;17(168):20200294. doi: 10.1098/rsif.2020.0294. Epub 2020 Jul 15.
Aligned cells provide direction-dependent mechanical properties that influence biological and mechanical function in native tissues. Alignment techniques such as casting and uniaxial stretching cannot fully replicate the complex fibre orientation of native tissue such as the heart. In this study, bioprinting is used to direct the orientation of cell alignment. A 0°-90° grid structure was printed to assess the robustness of the support-assisted bioprinting technique. The variation in the angles of the grid pattern is designed to mimic the differences in fibril orientation of native tissues, where angles of cell alignment vary across the different layers. Through bioprinting of a cell-hydrogel mixture, C2C12 cells displayed directed alignment along the longitudinal axis of printed struts. Cell alignment is induced through firstly establishing structurally stable constructs (i.e. distinct 0°-90° structures) and secondly, allowing cells to dynamically remodel the bioprinted construct. Herein reports a method of inducing a macroscale level of controlled cell alignment with angle variation. This was not achievable both in terms of methods (i.e. conventional alignment techniques such as stretching and electrical stimulation) and magnitude (i.e. hydrogel features with less than 100 µm features).
排列整齐的细胞提供了依赖于方向的机械性能，这些性能会影响天然组织中的生物学和机械功能。铸造和单轴拉伸等定向技术无法完全复制天然组织（如心脏）中复杂的纤维排列。在这项研究中，生物打印被用于指导细胞定向排列。打印了一个 0°-90°的网格结构，以评估支撑辅助生物打印技术的稳健性。网格图案角度的变化旨在模拟天然组织中纤维排列的差异，其中细胞排列的角度在不同层之间变化。通过细胞-水凝胶混合物的生物打印，C2C12 细胞沿着打印支柱的纵轴呈现定向排列。细胞的定向排列是通过首先建立结构稳定的构建体（即明显的 0°-90°结构），然后允许细胞动态重塑生物打印的构建体来实现的。本文报告了一种诱导具有角度变化的宏观水平的受控细胞排列的方法。这在方法（即拉伸和电刺激等传统定向技术）和数量级（即小于 100 µm 的水凝胶特征）上都无法实现。
