gelma

GelMA, or gelatin methacrylate, is a photopolymerizable hydrogel derived from gelatin that combines the biological activity of gelatin with chemically tunable crosslinking. It is widely used in tissue engineering and biofabrication due to its biocompatibility and ability to support cell adhesion and remodeling.

Synthesis and chemistry: GelMA is produced by reacting gelatin with glycidyl methacrylate under basic conditions, introducing methacryloyl groups onto lysine residues. The resulting material is purified to remove unreacted reagents and is typically lyophilized for storage. The degree of methacrylation, along with GelMA concentration, determines the crosslinking density and thus the mechanical properties of the final hydrogel.

Crosslinking and properties: GelMA hydrogels form through photopolymerization in the presence of a photoinitiator, such as Irgacure 2959 or LAP, when exposed to UV or visible light. The network properties can be tuned by adjusting the DoM and polymer concentration, producing gels with a wide range of stiffness (from soft to relatively stiff) and swelling behavior. The gelatin backbone retains bioactive motifs, including RGD sequences, and is susceptible to matrix metalloproteinase (MMP)–mediated degradation, enabling cell-mediated remodeling.

Applications: GelMA is used in 3D bioprinting, microfabrication of tissue scaffolds, and the creation of organoids and engineered tissues such as cartilage, bone, neural, and cardiac constructs. It is also employed in drug delivery studies and wound-healing models, where tunable mechanical properties and bioactivity are advantageous.

Advantages and limitations: GelMA offers biocompatibility, tunable mechanics, and intrinsic cell-adhesive features. Limitations include batch-to-batch variability of gelatin, potential cytotoxicity from photoinitiators, and the need to optimize crosslinking conditions to balance stability with biological activity.