Department of Health Science and Technology, ETH Zurich, Zurich, Switzerland.
Present address: Department of Bionanoscience, TU Delft, Delft, The Netherlands.
Biofabrication. 2020 Dec 17;13(1). doi: 10.1088/1758-5090/abc39b.
3D bioprinting has seen a tremendous growth in recent years in a variety of fields such as tissue engineering, drug testing and regenerative medicine, which has led researchers and manufacturers to continuously advance and develop novel bioprinting techniques and materials. Although new bioprinting methods are emerging (e.g. contactless and volumetric bioprinting), micro-extrusion bioprinting remains the most widely used method. Micro-extrusion bioprinting, however, is still largely dependent on the conventional pneumatic extrusion process, which relies heavily on homogenous biomaterial inks and bioinks to maintain a constant material flow rate. Augmenting the functionality of the bioink with the addition of nanoparticles, cells or biopolymers can induce inhomogeneities resulting in uneven material flow during printing and/or clogging of the nozzle, leading to defects in the printed construct. In this work, we evaluated a novel extrusion technique based on a miniaturized progressive cavity pump (PCP) which allows precise control over the volumetric flow rate by positive displacement. We compared the accuracy and precision of this system to the pneumatic extrusion system and tested both systems for their effect on cell viability after extrusion. The PCP achieved a significantly higher accuracy and precision compared to the pneumatic system, while maintaining good viability. These improvements were independent of the bioink composition, printing speed or nozzle size. This study demonstrates the merit of precise extrusion-process control in bioprinting by PCPs and investigates their influence on process-induced cell damage. PCPs are a promising tool for bioprinting and could help provide standardized and validated bioprinted constructs while leaving the researcher more freedom in the design of the bioinks.
3D 生物打印在近年来在组织工程、药物测试和再生医学等领域得到了迅猛的发展，这促使研究人员和制造商不断推进和开发新型生物打印技术和材料。尽管新的生物打印方法不断涌现（例如非接触式和体积式生物打印），但微挤出生物打印仍然是最广泛使用的方法。然而，微挤出生物打印在很大程度上仍然依赖于传统的气动挤出工艺，该工艺严重依赖于均匀的生物材料墨水和生物墨水来保持恒定的材料流速。通过添加纳米颗粒、细胞或生物聚合物来增强生物墨水的功能，可以诱导不均匀性，从而导致打印过程中材料流动不均匀和/或喷嘴堵塞，导致打印结构出现缺陷。在这项工作中，我们评估了一种基于微型连续腔泵（PCP）的新型挤出技术，该技术通过正位移可以精确控制体积流量。我们将该系统与气动挤出系统的准确性和精密度进行了比较，并测试了这两种系统在挤出后对细胞活力的影响。与气动系统相比，PCP 具有更高的准确性和精密度，同时保持良好的细胞活力。这些改进与生物墨水的组成、打印速度或喷嘴尺寸无关。本研究证明了 PCP 在生物打印中精确挤出过程控制的优势，并研究了它们对过程诱导的细胞损伤的影响。PCP 是生物打印的一种有前途的工具，它可以帮助提供标准化和经过验证的生物打印结构，同时为研究人员在生物墨水的设计方面提供更多的自由。
