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PERSPECTIVE

Roles of support materials in 3D bioprinting –

Present and future

*
Ratima Suntornnond , Jia An and Chee Kai Chua
Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological Universi-
ty, Singapore 639798, Singapore

Abstract: Bioprinting has been introduced as a new technique in tissue engineering for more than a decade. However,
characteristics of bioprinted part are still distinct from native human tissue and organ in terms of both shape fidelity and
functionality. Recently, the combination of at least two hydrogels or “multi-materials/multi-nozzles” bioprinting enables
simultaneous deposition of both model and support materials, thus advancing the complexity of bioprinted shapes from
2.5D lattice into micro-channeled 3D structure. In this article, a perspective on the roles of second bioinks or support
materials is presented and future outlook of sacrificial materials is discussed.
Keywords: hydrogel, support materials, bioprinting, additive manufacturing, tissue engineering

*Correspondence to: Ratima Suntornnond, Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang
Technological University, Singapore; Email: ratima001@e.ntu.edu.sg

Received: November 4, 2016; Accepted: December 7, 2016; Published Online: January 4, 2017
Citation: Suntornnond R, An J and Chua C K, 2017, Roles of support materials in 3D bioprinting – 3resent and future. International
Journal of Bioprinting, vol.3(1): 83–86. http://dx.doi.org/10.18063/IJB.2017.01.006.

1. Introduction hydrogels are low at the human body temperature
B printing of cell-hydrogel suspensions without any
(or before crosslinking stage). This may favor direct
ioprinting is an emerging technology that
shows potential for regenerative medicine and
change in environment or equipment such as temper-
[1–3]
other biomedical applications
. Unlike oth-
er 3D printing techniques which print non-living ma- ature control unit [2,8] , but it is difficult to print them
into 3D shapes without using strength enhancement
terials, bioprinting incorporates living materials dur- strategy (e.g. chemical crosslinking or adding thick-
ing the printing process. However, the bioprinted ener). A second reason is that there is a lack of suffi-
structures are still different from complex native hu- cient support materials suitable for bioink. Support,
man tissue or organ. One reason is that “Bioink” also known as sacrificial material or structure, is
which mostly refers to hydrogels has a relatively low a basic but important concept in 3D printing. It allows
mechanical integrity compared to other 3D printing the fabrication of overhang features and complex in-
materials such as metals, ceramics and polymers [4–7] . ternal structures. Similarly, in 3D bioprinting, it is
Some of the hydrogels are highly biocompatible and difficult to print 3D complex shapes and geometries
even able to promote tissue growth and tissue forma- without using support. Therefore, at the current
tion, but hydrogels that have good biocompatibility stage, bioprinting of complex hollow structures that
usually have low printability and low mechanical can completely mimic human’s vascular systems or
strength before and during printing. For example, col- hollow organs such as heart or kidney is very chal-
lagen and gelatin-methacrylate (GelMA) has good bio- lenging. Single material printing will not be sufficient
compatibility, but their printability is poor and the to provide all the required properties (including bio-
mechanical strength is low. The viscosities of both compatibility, mechanical integrity and printability) [1–9]

Roles of support materials in 3D bioprinting — 3resent and future. © 2017 Ratima Suntornnond, 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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