Effects of Gelatin Methacrylate Bio-ink Concentration on Mechano-Physical Properties and Human Dermal Fibroblast Behavior

Abstract

Gelatin-methacryloyl (GelMa) is a very versatile biomaterial widely used in various biomedical applications. The addition of methacryloyl makes it possible to have hydrogels with varying mechanical properties due to its photocuring characteristics. In addition, gelatin is obtained and derived from natural material; thus, it retains various cell-friendly motifs, such as arginine-glycine-aspartic acid, which then provides implanted cells with a friendly environment for proliferation and differentiation. In this study, we fabricated human dermal fibroblast cell (hDF)-laden photocurable GelMa hydrogels with varying physical properties (5%, 10%, and 15%) and assessed them for cellular responses and behavior, including cell spreading, proliferation, and the degree of extracellular matrix remodeling. Under similar photocuring conditions, lower concentrations of GelMa hydrogels had lower mechanical properties than higher concentrations. Furthermore, other properties, such as swelling and degradation, were compared in this study. In addition, our findings revealed that there were increased remodeling and proliferation markers in the 5% GelMa group, which had lower mechanical properties. However, it was important to note that cellular viabilities were not affected by the stiffness of the hydrogels. With this result in mind, we attempted to fabricate 5–15% GelMa scaffolds (20 × 20 × 3 mm3) to assess their feasibility for use in skin regeneration applications. The results showed that both 10% and 15% GelMa scaffolds could be fabricated easily at room temperature by adjusting several parameters, such as printing speed and extrusion pressure. However, since the sol-gel temperature of 5% GelMa was noted to be lower than its counterparts, 5% GelMa scaffolds had to be printed at low temperatures. In conclusion, GelMa once again was shown to be an ideal biomaterial for various tissue engineering applications due to its versatile mechanical and biological properties. This study showed the feasibility of GelMa in skin tissue engineering and its potential as an alternative for skin transplants.

3D-Printed Gelatin Methacryloyl-Based Scaffolds with Potential Application in Tissue Engineering

“…This fact is related to the formation of a more close-packed GelMA network as a consequence of the crosslinking reaction between more methacryloyl groups and initiation centers, as the calculated values of cross-linking density υ indicated ( Figure 12 ). All these results are in good agreement with other studies conducted on hydrogels and GelMA hydrogels [ 29 , 30 ].…”

“…The GelMA precursor solution and, further, its crosslinked formulations were characterized by 1 H-NMR-spectrometry, Fourier-transform infrared spectrometry (ATR-FTIR) for structural characterization, circular dichroism (DC), dynamic light scattering (DLS) to determine the isoelectric point, the contact angle, swelling behavior to determine the hydrophilicity, printability for setting the printing parameters of the injectable formulations, and nanoindentation for testing the mechanical properties. In addition, in order to observe how the methacrylation degree and photoinitiator concentration affect the mechanical properties, the crosslinking density was calculated by rheology [ 28 , 29 ]. Finally, electronic microscopy (SEM) was used to determine the morphology of the obtained materials [ 30 ].…”

Deciphering the Molecular Mechanism of Water Interaction with Gelatin Methacryloyl Hydrogels: Role of Ionic Strength, pH, Drug Loading and Hydrogel Network Characteristics

“…Current scientific literature for water dynamics in GelMA hydrogels is sparse and is limited to the study of the swelling behavior on a macroscopic scale, with the total water content as the main output [37][38][39][40][41]. To date, the molecular interaction and organization between GelMA and water have not been reported.…”

Calcium Silicate-Activated Gelatin Methacrylate Hydrogel for Accelerating Human Dermal Fibroblast Proliferation and Differentiation

“…As can be seen, the degradation rate decreased with increases in the Si concentration, with Si0, Si0.5, and Si1.0 having 53%, 65%, and 72% of their mass remaining after 14 days of incubation. Interestingly, our previous studies reported that pure GelMa hydrogels at concentrations of 5–15% exhibited almost complete degradation after 14 days of incubation [ 15 ]. Compared to pure GelMa hydrogens, Si ion-containing hydrogels are thought to be better suited for long-term wound healing because they can last until optimal wound healing occurs and prevent secondary infections and moisture loss [ 20 ].…”

“…Gelatin is a well-known biomaterial that is commonly used in the fabrication of hydrogels in the form of a gelatin derived from collagen, thus making it possible to retain the natural motifs of the extracellular matrix and providing excellent biocompatibility, biodegradability, and non-toxicity [ 13 , 14 ]. Furthermore, gelatin can be modified with methacryloyl groups (GelMa) to allow photo-crosslinking so as to provide customizable mechanical properties [ 15 ]. The mechanical strength of GelMa could be adjusted by varying the concentration of methacrylol, strength of UV photo-crosslinking, and duration of UV exposure.…”