Visible Light Photoinitiation of Cell-Adhesive Gelatin Methacryloyl Hydrogels for Stereolithography 3D Bioprinting

Abstract

We present the first cell-attachable and visible-light-crosslinkable bioinks based on gelatin methacryloyl (GelMA) with eosin Y (EY) photoinitiation for stereolithography three-dimensional (3D) bioprinting. To develop a visible-light-crosslinkable hydrogel, we systematically studied five combinations of GelMA and EY photoinitiator with various concentrations. Their mechanical properties, microstructures, and cell viability and confluency after encapsulation were investigated rigorously to elucidate the effects of the EY and GelMA macromer concentrations on the characteristics of the hydrogel. Experimental results show that the compressive Young's modulus and pore size are positively affected by the concentration of EY, whereas the mass swelling ratio and cell viability are negatively affected. Increasing the concentration of GelMA helps in improving the compressive Young's modulus and cell attachment. We further employed the developed visible-light-based stereolithography bioprinting system to print the patterned cell-laden hydrogels to demonstrate the bioprinting applications of the developed hydrogel. We observed good cell proliferation and the formation of a 3D cellular network inside the printed pattern at day 5, which proves the great feasibility of using EY-GelMA as the bioinks for biofabrication and tissue engineering.

Biofabrication of Gelatin Tissue Scaffolds with Uniform Pore Size via Microbubble Assembly

“…Pore size and size distribution as well as interconnectivity are critical parameters for cellular bioactivity . Porous character of scaffold material governs the cell penetration, nutrient transport along with degradation profile, mechanical behavior, angiogenesis, and differentiation . The influence of pore homogeneity on aforementioned features remains a much lesser studied parameter compared with overall porosity or bulk properties of the scaffold materials.…”

“…[31] Porous character of scaffold material governs the cell penetration, nutrient transport along with degradation profile, mechanical behavior, angiogenesis, and differentiation. [32][33][34] The influence of pore homogeneity on aforementioned features remains a much lesser studied parameter compared with overall porosity or bulk properties of the scaffold materials. The T-junction microfluidic setup has been used to fabricate microbubbles and particles with a very low polydispersity index.…”

Engineered 3D Polymer and Hydrogel Microenvironments for Cell Culture Applications

“…However, the compressive modulus changed from 0.5 MPa to 18 MPa [328]. The use of Eosin Y as a photoinitiator allowed SLA printing of GelMA using visible light [329]. Lastly, a recent development in inkjet printing of GelMA microdroplets was studied, where the use of electrostatic attraction allowed printing of 100 µm droplets of GelMA rapidly and smoothly, with minimal damage to encapsulated cells [330].…”

The Role of Photochemical Reactions in the Development of Advanced Soft Materials for Biomedical Applications

“…Initially, systems were based in the use of UV‐initiated polymerizations to form the 3D molds. The disadvantage of these methods is that the UV light can cause damage to the surrounding biological materials, hampering their utilization in some applications . In order to address this issue, the fabrication of cell‐laden hydrogels avoiding the use of UV initiators has been carried out.…”