3D-Printed Gelatin Methacrylate Scaffolds with Controlled Architecture and Stiffness Modulate the Fibroblast Phenotype towards Dermal Regeneration

Abstract

Impaired skin wound healing due to severe injury often leads to dysfunctional scar tissue formation as a result of excessive and persistent myofibroblast activation, characterised by the increased expression of α-smooth muscle actin (αSMA) and extracellular matrix (ECM) proteins. Yet, despite extensive research on impaired wound healing and the advancement in tissue-engineered skin substitutes, scar formation remains a significant clinical challenge. This study aimed to first investigate the effect of methacrylate gelatin (GelMA) biomaterial stiffness on human dermal fibroblast behaviour in order to then design a range of 3D-printed GelMA scaffolds with tuneable structural and mechanical properties and understand whether the introduction of pores and porosity would support fibroblast activity, while inhibiting myofibroblast-related gene and protein expression. Results demonstrated that increasing GelMA stiffness promotes myofibroblast activation through increased fibrosis-related gene and protein expression. However, the introduction of a porous architecture by 3D printing facilitated healthy fibroblast activity, while inhibiting myofibroblast activation. A significant reduction was observed in the gene and protein production of αSMA and the expression of ECM-related proteins, including fibronectin I and collagen III, across the range of porous 3D-printed GelMA scaffolds. These results show that the 3D-printed GelMA scaffolds have the potential to improve dermal skin healing, whilst inhibiting fibrosis and scar formation, therefore potentially offering a new treatment for skin repair.

Recombinant Human Collagen-Based Bioinks for the 3D Bioprinting of Full-thickness Human Skin Equivalent

“…There was no significant difference among three groups for the expression of a-SMA. Similar trends on expression of the Col-I and a-SMA have been reported by literature where hydrogels with stiffness comparable to ours have been used[ 43 , 44 ]. These results illustrated that 7.5 wt% GelMA could comprehensively support the cellular activities of the encapsulated skin fibroblasts; therefore, it was selected in constructing the in vitro dermis.…”

A Review on the Design of Hydrogels With Different Stiffness and Their Effects on Tissue Repair

“…Different synthesis methods can obtain hydrogels with different stiffness, and the different stiffness of hydrogels led to various cell behaviors. Different stiffness hydrogels can affect the behavior of stem cells, MSCs, fibroblasts ( Ibañez et al, 2021 ), macrophages, and other cells, thereby affecting the process of tissue repair or bone defect. In particular, hydrogels affect the phenotype of macrophages through changes in stiffness ( Lv et al, 2015 ), leading to changes in tissue inflammatory environment and angiogenesis, and ultimately promoting wound healing.…”

Polyphenol derived bioactive carbon quantum dot-incorporated multifunctional hydrogels as an oxidative stress attenuator for antiaging and in vivo wound-healing applications

“…48 The flaky and macroporous morphology of the GelMA scaffold can improve the swelling efficiency and facilitate fibroblast proliferation toward wound healing. 49–52 The peaks in the FT-IR spectra of the freeze-dried GelMA and GelMA-G and GelMA-Y composites were similar because of the low amounts of CQDs incorporated in the hydrogel matrices and lack of chemical interactions between the CQDs and the matrices (Fig. S6, ESI†).…”