Page 100 - IJB-6-4

ORIGINAL ARTICLE

Rational Design of a Triple-Layered Coaxial Extruder

System: in silico and in vitro Evaluations Directed

Toward Optimizing Cell Viability

Christian Silva *, Carlos J. Cortés-Rodriguez , Jonas Hazur , Supachai Reakasame , Aldo R. Boccaccini 2
2
2
1
1
1 Department of Mechanical Engineering and Mechatronics, School of Engineering, Universidad Nacional de Colombia,
Bogotá 111321, Colombia
2 Department of Materials Science and Engineering, Institute of Biomaterials, University of Erlangen-Nuremberg, Erlangen
91058, Germany

Abstract: Biofabrication is a rapidly evolving field whose main goal is the manufacturing of three-dimensional (3D) cell-laden
constructs that closely mimic tissues and organs. Despite recent advances on materials and techniques directed toward the
achievement of this goal, several aspects such as tissue vascularization and prolonged cell functionality are limiting bench-to-
bedside translation. Extrusion-based 3D bioprinting has been devised as a promising biofabrication technology to overcome these
limitations, due to its versatility and wide availability. Here, we report the development of a triple-layered coaxial nozzle for use in
the biomanufacturing of vascular networks and vessels. The design of the coaxial nozzle was first optimized toward guaranteeing
high cell viability upon extrusion. This was done with the aid of in silico evaluations and their subsequent experimental validation
by investigating the bioprinting of an alginate-based bioink. Results confirmed that the values for pressure distribution predicted
by in silico experiments resulted in cell viabilities above 70% and further demonstrated the effect of layer thickness and extrusion
pressure on cell viability. Our work paves the way for the rational design of multi-layered coaxial extrusion systems to be used in
biofabrication approaches to replicate the very complex structures found in native organs and tissues.
Keywords: Three-dimensional bioprinting, Coaxial nozzle, Vascularized tissues, Tissue-engineered vessels, Biomaterials

*Corresponding Author: Christian Silva, Department of Mechanical Engineering and Mechatronics, School of Engineering, Universidad
Nacional de Colombia, Bogotá 111321, Colombia; casilvaca@unal.edu.co
Received: May 12, 2020; Accepted: June 22, 2020; Published Online: July 24, 2020
Citation: Silva C, Cortés-Rodriguez C, Hazur J, et al., 2020, Rational Design of a Triple-Layered Coaxial Extruder System:
in silico and in vitro Evaluations Directed Toward Optimizing Cell Viability, Int J Bioprint, 6(4): 282. DOI: 10.18063/ijb.v6i4.282.

1 Introduction technique for achieving 3D structures of sufficient
complexity, since it can work with a broad range of
Three-dimensional (3D) bioprinting is an additive cell densities and printable materials [4,5] . Moreover,
manufacturing technology that permits the the versatility and affordability provided by EBB
spatiotemporal patterning of hydrogels embedded
with cells, namely bioinks, into 3D structures [1,2] . systems have contributed to its positioning as the
Its goal is to fabricate cell-laden constructs that most popular biofabrication technology among
mimic tissues and organs, where cell viability is researchers worldwide for applications that range
preserved and overall physiological functionality from cancer research and drug testing to tissue
[6]
is replicated [1,3] . Among its several techniques, engineering .
extrusion-based bioprinting (EBB) has emerged Replicating complex internal tissue structures
as the most promising additive manufacturing is, however, still a challenge for the available

© 2020 Silva, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International
License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the
original work is properly cited.
96