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RESEARCH ARTICLE

Coaxial nozzle-assisted electrohydrodynamic printing

for microscale 3D cell-laden constructs

Hongtao Liang, Jiankang He , Jinke Chang, Bing Zhang, Dichen Li
*
State key laboratory for manufacturing systems engineering, Xi’an Jiaotong University, Xi’an, China
Abstract: Cell printing has found wide applications in biomedical fields due to its unique capability in fabricating living
tissue constructs with precise control over cell arrangements. However, it is still challenging to print cell-laden 3D structures
simultaneously with high resolution and high cell viability. Here a coaxial nozzle-assisted electrohydrodynamic cell printing
strategy was developed to fabricate living 3D cell-laden constructs. Critical process parameters such as feeding rate and
stage moving speed were evaluated to achieve smaller hydrogel filaments. The effect of CaCl 2 feeding rate on the printing
of 3D alginate hydrogel constructs was also investigated. The results indicated that the presented strategy can print 3D
hydrogel structures with relatively uniform filament dimension (about 80 μm) and cell distribution. The viability of the
encapsulated cells was over 90%. We envision that the coaxial nozzle-assisted electrohydrodynamic printing will become a
promising cell printing strategy to advance biomedical innovations.
Keywords: electrohydrodynamic printing; cell printing; bioprinting; biofabrication; tissue engineering
* Correspondence to: Jiankang He, State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
jiankanghe@mail.xjtu.edu.cn
Received: October 1, 2017; Accepted: November 13, 2017; Published Online: November 22, 2017

Citation: Liang H, He J, Chang J, et al., 2018, Coaxial nozzle-assisted electrohydrodynamic printing for microscale 3D cell-laden constructs.
Int J Bioprint, 4(1): 127. http://dx.doi.org/10.18063/IJB.v4i1.127
1. Introduction dro dy namically induced material flows [12–18] . Several
process parameters had been investigated to achieve
In the past decades, cell printing has been extensively stable electrohydrodynamic printing process, such as
studied in biomedical fields due to its unique capability applied voltage, moving speed, feeding rate of materials
in precise patterning of biological components such and inter diameter of nozzle [19–26] . Recent explorations
as living cells in a controlled manner [1–3] . Several indicate that biomaterials like living cells and hydrogels
bioprinting techniques have been developed mainly can be electrohydrodynamically printed and maintained
including microextrusion-based printing, inkjet printing their viability [27–30] . For example, Gasperini et al. further
and laser-assisted printing [4–6] . However, there are some fabricated hollow cylindrical cell-laden structures
drawbacks of these existing strategies in fabricating using an electrohydrodynamic bioprinter [31] . Yao et al.
complex three-dimensional (3D) structures with fabricated 3D cell-laden alginate structures with the
relatively high resolution and high cell viability in a help of aerosol crosslinking mechanism by combining
costly effective way. For example, inkjet cell printing electrohydrodynamic printing and traditional extrusion-
employs thermal or piezoelectric effect to print cell- based cell printing [32] . However, the size of these
hydrogel droplets, which affects cell viability and electrohydrodynamically printed hydrogel filaments was
limits low cell concentration [4,7] . Laser-assisted printing commonly larger than 200 μm.
commonly requires costly equipment and cannot We previously developed a novel electrohydrodynamic
fabricate 3D constructs [6,8] . Microextrusion-based cell cell printing strategy that can fabricate cell-laden
printing has the drawbacks of low printing resolution as constructs with microscale resolution (<100 μm) and
well as the side effect of flow-induced shear stress on high cell viability (>95%) . However, alginate filaments
[33]
cell viability [9–11] . were mainly crosslinked by the calcium ions diffused
Electrohydrodynamic jetting or printing recently from the collecting substrate of agarose hydrogel, which
attracts extensive attentions in fabricating high- limited the layer number of the electrohydrodynamically
resolution features based on the principle of elec tro hy- printed hydrogel smaller than 20. Here a coaxial nozzle-

Coaxial nozzle-assisted electrohydrodynamic printing for microscale 3D cell-laden constructs. © 2018 Liang H, 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.
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