Page 444 - IJB-9-4

International Journal of Bioprinting

RESEARCH ARTICLE
Developing a bioink for single-step deposition

and maturation of human epidermis

Ruth Jinfen Chai , Wan Ling Wong , Cyrus Weijie Beh *
1,2
1
1
1 Molecular Engineering Lab, Institute of Molecular and Cell Biology, Singapore 138673, Singapore
2 Institute of Bioengineering and Bioimaging, Singapore 138669, Singapore
(This article belongs to the Special Issue: Related to 3D printing technology and materials)

Abstract
Patients with severe burns, which cause extensive damage to their skin, require
rapid intervention to prevent life-threatening hypothermia, infection, and fluid
loss. Current treatments typically involve surgical excision of the burned skin and
reconstruction of the wound with the aid of skin autografts. However, there is a lack
of donor site in the most severe cases. While alternative treatments such as cultured
epithelial autografts and “spray-on” skin can allow much smaller donor tissues to be
used (and hence reduce donor site morbidity), they present their own challenges
in terms of fragility of the tissues and control of the cell deposition, respectively.
Recent advances in bioprinting technology have led researchers to explore its use to
fabricate skin grafts, which depend on several factors, including appropriate bioinks,
cell types, and printability. In this work, we describe a collagen-based bioink that
allows the deposition of a contiguous layer of the keratinocytes directly onto the
wound. Special attention was given to the intended clinical workflow. For example,

*Corresponding author: since media changes are not feasible once the bioink is deposited onto the patient,
Cyrus Weijie Beh we first developed a media formulation designed to permit a single deposition step
(beh_cyrus@ibb.a-star.edu.sg) and promote self-organization of the cells into the epidermis. Using a collagen-
Citation: Chai RJ, Wong WL, based dermal template populated with dermal fibroblasts, we demonstrated by
Beh CW, 2023, Developing a bioink immunofluorescence staining that the resulting epidermis recapitulates the features
for single-step deposition and of natural skin in expressing p63 (stem cell marker), Ki67 and keratin 14 (proliferation
maturation of human epidermis. Int
J Bioprint, 9(4): 738. markers), filaggrin and keratin 10 (keratinocyte differentiation and barrier function
https://doi.org/10.18063/ijb.738 markers), and collagen type IV (basement membrane protein involved in adherence
Received: September 09, 2022 of the epidermis to the dermis). While further tests are still required to verify its utility
as a burn treatment, based on the results we have achieved thus far, we believe that
Accepted: September 30, 2022
our current protocol can already produce donor-specific model for testing purposes.
Published Online: April 26, 2023
Copyright: © 2023 Author(s). Keywords: Human skin equivalents; Bioprinting; In vitro models; Tissue regeneration;
This is an Open Access article
distributed under the terms of the Skin; Tissue engineering
Creative Commons Attribution
License, permitting distribution,
and reproduction in any medium,
provided the original work is
properly cited. 1. Introduction
Publisher’s Note: Whioce According to the World Health Organization (WHO), burns are a global public health
Publishing remains neutral with issue that is estimated to cause 180,000 deaths yearly . In 2004, more than 11 million
[1]
regard to jurisdictional claims in [1]
published maps and institutional people were burned seriously enough to require medical attention . Patients with severe
affiliations. burns suffer extensive damage to their skin that requires immediate intervention to prevent

Volume 9 Issue 4 (2023) 436 https://doi.org/10.18063/ijb.738