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RESEARCH ARTICLE
Optimizing nozzle design in extrusion-based 3D bioprinting to minimize mechanical stress and enhance cell viability
Lorenzo Lombardi1 ,
Annachiara Scalzone2,3* ,
Chiara Ausilio1 ,
Piergiorgio Gentile2,4* ,
Daniele Tammaro1
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1 Department of Chemical, Materials and Production Engineering, Polytechnic School and Basic Sciences, University of Naples Federico II, Naples, Campania,
Italy
2 School of Engineering, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle upon Tyne, Tyne and Wear,
United Kingdom
3 Center for Advanced Biomaterials for Health Care, Italian Institute of Technology, Naples, Campania,
Italy
4 Center for Biomaterials and Tissue Engineering, Polytechnic University of Valencia, Valencia, Valencia,
Spain
IJB, 025190182 https://doi.org/10.36922/IJB025190182
Received: 5 May 2025 | Accepted: 16 June 2025 | Published online: 16 June 2025
© 2025 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 ( https://creativecommons.org/licenses/by/4.0/ )
Abstract
Extrusion-based three-dimensional bioprinting is a widely used technique for fabricating cell-laden constructs in tissue engineering and regenerative medicine. However, the mechanical stresses experienced by cells during the printing process can negatively affect their viability. This study examines the influence of nozzle geometry—specifically contraction angle and outlet diameter—on stress distribution and its effects on cell survival. Through a combination of experimental analysis and theoretical modeling, the impacts of nozzle design on the balance between shear and extensional stresses during bioprinting are explored. The findings highlight the importance of optimizing nozzle parameters to minimize mechanical damage and enhance post-printing cell viability. The proposed model provides a framework for guiding nozzle design, offering insights into the development of customized bioprinting strategies that enhance construct fidelity and biological functionality. These results contribute to advancing bioprinting techniques for applications in tissue engineering and regenerative medicine.
Graphical abstract
Keywords
Customized nozzles
Extensional stress
Extrusion bioprinting
Funding
None.
Conflict of interest
The authors declare they have no competing interests.
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