AccScience Publishing / IJB / Volume 11 / Issue 4 / DOI: 10.36922/IJB025160154
RESEARCH ARTICLE

3D printing of the keloid scar using tunable GelMA-based bioinks for skin fibrosis modeling

Laurensia Danis Anggradita1,2† Murugaiyan Manimohan3† Sung Sik Hur1† Taekyun Kim1,2 Wonjong Seon1,2 Mohamed Aboobucker Sithique3 Seung Min Nam4* Yongsung Hwang1,2*
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1 Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Chungnam 31151, Republic of Korea
2 Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan, Chungnam 31151, Republic of Korea
3 PG & Research Department of Chemistry, Islamiah College, Thiruvalluvar University, Vaniyambadi, Tamil Nadu 635752, India.
4 Department of Plastic and Reconstructive Surgery, Soonchunhyang University College of Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Gyeonggi 14584, Republic of Korea
†These authors contributed equally to this work.
IJB 2025, 11(4), 446–461; https://doi.org/10.36922/IJB025160154
Received: 19 April 2025 | Accepted: 23 July 2025 | Published online: 23 July 2025
© 2025 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract

The development of mechanically tunable and cytocompatible hydrogels is critical for advancing three-dimensional (3D) bioprinting in tissue engineering. Here, we report a composite bioink composed of gelatin methacrylate (GelMA), methylcellulose, sodium alginate, and laponite-RDS. This formulation supports extrusion-based printing without ionic crosslinkers, mimics the extracellular matrix (ECM), and maintains stable viscoelasticity under physiological conditions (37°C, pH 7.4). Electrostatic and hydrogen bonding interactions among the charged polymers enhance pre-gel viscosity, shear-thinning behavior, and print fidelity. To evaluate its potential in disease modeling, patient-derived keloid fibroblasts were encapsulated in 3D-bioprinted constructs using two GelMA-based formulations with different stiffness levels, such as soft (G4A1M1R1, 2.1 kPa) and stiff (G5A1M1R1, 7.9 kPa), chosen to replicate the mechanical properties of normal dermis and keloid tissue, respectively. Both constructs exhibited excellent cell viability after three days, confirming cytocompatibility. Furthermore, matrix stiffness significantly regulated fibrotic gene expression. The stiffer hydrogel induced higher expression of COL1, MMP2, and IL6, suggesting enhanced myofibroblast activation and ECM remodeling. Immunofluorescence staining further confirmed elevated protein levels of α-SMA, FSP1, and actin stress fibers (F-actin) in the stiff construct, consistent with keloid pathology. Taken together, these results demonstrate that the GelMA-based bioink enables stiffness-dependent modulation of fibrotic responses, offering a simplified yet relevant 3D model of fibrotic skin. This platform may provide a useful basis for future studies on keloid progression and preliminary antifibrotic drug screening.  

Graphical abstract
Keywords
Bioinks
Bioprinting
Keloid
Shape fidelity
Skin fibrosis
Viscoelastic properties
Funding
This work was supported by the Soonchunhyang University Research Fund and the National Research Foundation of Korea funded by the Ministry of Science and ICT (MSIT) (grant numbers: RS-2019-NR040068, RS-2023-00284258, and 2017R1D1AB03029770).
Conflict of interest
The authors declare they have no competing interests.
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International Journal of Bioprinting, Electronic ISSN: 2424-8002 Print ISSN: 2424-7723, Published by AccScience Publishing