Extrusion-based bioprinting: considerations toward gelatin-alginate bioink
Abstract
Purpose
This study aims to develop a simplified bioink preparation method that can be applied to most hydrogel bioinks used in extrusion-based techniques.
Design/methodology/approach
The parameters of the bioprinting process significantly affect the printability of the bioink and the viability of cells. In turn, the bioink formulation and its physicochemical properties may influence the appropriate range of printing parameters. In extrusion-based bioprinting, the rheology of the bioink affects the printing pressure, cell survival and structural integrity. Three concentrations of alginate-gelatin hydrogel were prepared and printed at three different flow rates and nozzle gauges to investigate the print parameters. Other characterizations were performed to evaluate the hydrogel structure, printability, gelation time, swelling and degradation rates of the bioink and cell viability. An experimental design was used to determine optimal parameters. The analyses included live/dead assays, rheological measurements, swelling and degradation.
Findings
The experimental design results showed that the hydrogel flow rate substantially influenced printing accuracy and pressure. The best hydrogel flow rate in this study was 10 ml/h with a nozzle gauge of 18% and 4% alginate. Three different concentrations of alginate-gelatin hydrogels were found to exhibit shear-thinning behavior during printing. After seven days, 46% of the structure in the 4% alginate-5% gelatin sample remained intact. After printing, the viability of skin fibroblast cells for the optimized sample was 91%.
Originality/value
This methodology offers a straightforward bioink preparation method applicable to the majority of hydrogels used in extrusion-based procedures. This can also be considered a prerequisite for cell printing.
Keywords
Acknowledgements
The authors thank Zist Negar Amirkabir Ltd. for their technical support and Dr Mitra Asadi-Eydivand and Dianoosh Kalhori for their insightful suggestions.
Declarations
Funding declaration: This research received no specific grants from any public, commercial or not-for-profit funding agency.
Conflicts of interest: The authors declare no conflict of interest.
Data availability: The data that support the findings of this study are available from the corresponding authors (solati@aut.ac.ir, keshvari@aut.ac.ir) upon reasonable request.
Ethical approval: No animal or human experiments were conducted in this study. In this study, no tests were performed on humans or animals.
Contributions: The authors confirm their contribution to the study: study conception and design: Mehran Solati-Hashjin and Hamid Keshvari; data collection: Kimia Abedi; analysis and interpretation of results: Kimia Abedi, Hamid Keshvari and Mehran Solati-Hashjin; and draft manuscript preparation: Kimia Abedi and Mehran Solati-Hashiin. All authors have reviewed the results and approved the final version of the manuscript.
Citation
Abedi, K., Keshvari, H. and Solati-Hashjin, M. (2024), "Extrusion-based bioprinting: considerations toward gelatin-alginate bioink", Rapid Prototyping Journal, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/RPJ-06-2023-0207
Publisher
:Emerald Publishing Limited
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