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RESEARCH ARTICLE

Extrusion-Based Bioprinting through Glucose-Mediated

Enzymatic Hydrogelation

Enkhtuul Gantumur, Masaki Nakahata, Masaru Kojima and Shinji Sakai*
Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka
560-8531, Japan

Abstract: We report an extrusion-based bioprinting approach, in which stabilization of extruded bioink is achieved through
horseradish peroxidase (HRP)-catalyzed cross-linking consuming hydrogen peroxide (H O ) supplied from HRP and glucose.
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The bioinks containing living cells, HRP, glucose, alginate possessing phenolic hydroxyl (Ph) groups, and cellulose nanofiber
were extruded to fabricate 3D hydrogel constructs. Lattice- and human nose-shaped 3D constructs were successfully printed
and showed good stability in cell culture medium for over a week. Mouse 10T1/2 fibroblasts enclosed in the printed constructs
remained viable after 7 days of culture. It was also able to switch a non-cell-adhesive surface of the printed construct to cell-
adhesive surface for culturing cells on it through a subsequent cross-linking of gelatin possessing Ph moieties. These results
demonstrate the possibility of utilizing the presented cross-linking method for 3D bioprinting.
Keywords: Enzymatic hydrogelation, Horseradish peroxidase, Glucose, Alginate, Cellulose nanofiber, Bioink, Extrusion-
based bioprinting

*Corresponding Author: Shinji Sakai, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka
University, Toyonaka, Osaka 560-8531, Japan; sakai@cheng.es.osaka-u.ac.jp

Received: November 18, 2019; Accepted: January 02, 2020; Published Online: January 21, 2020
Citation: Gantumur E, Nakahata M, Kojima M, et al., 2020, Extrusion-based bioprinting through glucose-mediated enzymatic
hydrogelation. Int J Bioprint, 6(1):250. DOI: 10.18063/ijb.v6i1.250.

1 Introduction Besides, the available bioprinting strategies
[12]
including inkjet-based [13,14] , laser-assisted [15,16] ,
Fabrication of three-dimensional (3D) tissues and stereolithography-based [17,18] , extrusion-based
has been a subject of interest in the fields of bioprinting is the most extensively adopted
[19]
tissue engineering and regenerative medicine for strategy due to its simplicity, printing precision, and
over the past decades. The classic biofabrication a variety of applicable biomaterials. In extrusion
techniques, such as solid or soft material-based bioprinting, viscous solutions are extruded from
scaffolding [1-3] and self-assembling of cell sheets a nozzle as inks on a substrate surface based on
or spheroids , have limitations to mimic the the digital design. The extruded inks must be
[4]
structure and function of the natural tissues that stabilized into solid hydrogels before spreading
are well-organized with multicellular population, for getting the constructs with designed shapes. In
a variety of extracellular matrix, growth factors, general, the stabilization is accomplished through
and bioactive compounds . Recent trend in the cross-linking of polymers in the inks resulting
[5]
the fields is 3D bioprinting, [6-8] which enables in hydrogelation. Various cross-linking methods
the deposition of living cells with biomaterials have been applied to the extrusion bioprinting [20,21] .
(i.e., bioinks) at micrometer precision to replicate To fabricate a structure having a complicated
the microarchitecture of targeted tissue [9-11] . structure like natural tissues, we believe that it

© 2020 Gantumur, 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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