AccScience Publishing / IJB / Online First / DOI: 10.36922/ijb.1974

Man vs. machine: Automated bioink mixing device improves reliability and reproducibility of bioprinting results compared to human operators

Dongwei Wu1 Shumin Pang2 Viola Röhrs1 Johanna Berg1 Ahmed S. M. Ali1 Yikun Mei1 Mathias Ziersch1 Beatrice Tolksdorf1 Jens Kurreck1*
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1 Chair of Applied Biochemistry, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
2 Chair of Advanced Ceramic Materials, Institute of Material Science and Technology, Technische Universität Berlin, Berlin, Germany
Submitted: 5 October 2023 | Accepted: 14 December 2023 | Published: 12 February 2024
© 2024 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( )

The bioink mixing process is highly relevant to the bioink quality, which is the basis for reproducible extrusion-based three-dimensional (3D) bioprinting (EBB). Currently, most bioinks mixed by skilled human operators show variations in terms of cell homogeneity and biological properties as well as other properties. For preparation of many types of bioinks, striking the balance between homogeneity and cell viability remains a major challenge. This study investigates the relationship between bioink homogeneity and mixing parameters, particularly mixing speed and number of exchanges, utilizing a customized automated device. We found that up to a certain point, increasing the rate of mixing led to a better distribution of cells within the bioink, but beyond that point, there was a detrimental effect on cell viability. In contrast, the mixing number had less impact on the physiological properties of the cells in the bioink. Furthermore, a comparison between skilled human and machine bioink mixing revealed that the machine consistently provided better outcomes in terms of bioink homogeneity, cell distribution, and cell viability, highlighting the advantages and importance of standardizing the bioink mixing process. The methodology and approaches in this study can improve the reproducibility and reliability of EBB bioink and may thereby advance the field of 3D bioprinting in various applications.

Hydrogel mixing
Mixing device
Cell viability
This research was supported by the Chinese Scholarship Council (CSC; fellowship No. 201906780024 to D.W., and fellowship No. 201906780023 to S.P.). Financial support from the Einstein Foundation Berlin (Einstein Center 3R, EZ-2020-597-2) is gratefully acknowledged.
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Conflict of interest
The authors declare no conflicts of interest.
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International Journal of Bioprinting, Electronic ISSN: 2424-8002 Print ISSN: 2424-7723, Published by AccScience Publishing