Page 19 - IJB-9-6

International

Journal of Bioprinting

RESEARCH ARTICLE
Computational fluid dynamics for the

optimization of internal bioprinting parameters
and mixing conditions

Gokhan Ates *, Paulo Bartolo *
1,3
1,2
1 Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester,
Manchester, United Kingdom
2 Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang
Technological University, Singapore
3
Department of Mechanical Engineering, Abdullah Gul University, Kayseri, Turkey

Abstract

Tissue engineering requires the fabrication of three-dimensional (3D) multimaterial
structures in complex geometries mimicking the hierarchical structure of biological
tissues. To increase the mechanical and biological integrity of the tissue engineered
structures, continuous printing of multiple materials through a printing head
consisting of a single nozzle is crucial. In this work, numerical analysis was carried
out to investigate the extrusion process of two different shear-thinning biomaterial
solutions (alginate and gelatin) inside a novel single-nozzle dispensing system
consisting of cartridges and a static mixer for varying input pressures, needle
geometries, and outlet diameters. Systematic analysis of the dispensing process was
*Corresponding authors: conducted to describe the flow rate, velocity field, pressure drop, and shear stress
Gokhan Ates
(gokhan.ates@manchester.ac.uk) distribution throughout the printing head. The spatial distribution of the biopolymer
Paulo Bartolo solutions along the mixing chamber was quantitatively analyzed and the simulation
(pbartolo@ntu.edu.sg) results were validated by comparing the pressure drop values with empirical
correlations. The simulation results showed that the proposed dispensing system
Citation: Ates G, Bartolo P, 2023,
Computational fluid dynamics for the enables to fabricate homogenous material distribution across the nozzle outlet. The
optimization of internal bioprinting predicted shear stress along the proposed printing head model is lower than the
parameters and mixing conditions. critical shear values which correspond to negligible cell damage, suggesting that
Int J Bioprint, 9(6): 0219.
https://doi.org/10.36922/ijb.0219 the proposed dispensing system can be used to print cell-laden tissue engineering
constructs.
Received: October 05, 2022
Accepted: December 21, 2022
Published Online: June 22, 2023
Keywords: 3D Printing; Bioprinting; Biomaterials; Computational fluid dynamics;
Copyright: © 2023 Author(s). Extrusion; Tissue engineering
This is an Open Access article
distributed under the terms of the
Creative Commons Attribution
License, permitting distribution
and reproduction in any medium, 1. Introduction
provided the original work is
properly cited. Three-dimensional (3D) bioprinting technology, within the rapidly evolving field
Publisher’s Note: AccScience of biomanufacturing, enables to engineer predesigned, volumetric tissue-like
Publishing remains neutral with structures with a spatially controlled distribution of cells and biomolecules, making it
regard to jurisdictional claims in [1-3]
published maps and institutional a unique tool for a broad range of tissue engineering applications . Bioinks are the
[4]
affiliations. bioprintable materials composed of hydrogels encapsulating cells or cell aggregates .

Volume 9 Issue 6 (2023) 11 https://doi.org/10.36922/ijb.0219