PhotoGel is lyophilized, sterile, medium degree of methacrylation (~50%) methacrylated gelatin. PhotoGel provides 3D gelatin hydrogels with the unique attributes to be prepared at various concentrations and photocrosslinked (requires a photoinitiator) to provide various gel stiffness. The PhotoGel kit consists of purified methacrylated porcine gelatin and a photoinitiator. The gelatin is type A 300 bloom. PhotoGel is produced from methacrylated gelatin where the gelatin has been modified by reacting the free amines, primarily the ε-amines groups of the lysine residues as well as the a-amines groups on the N-termini. The photoinitiator consists of LAP which allows visible light crosslinking of the gelatin at 405 nm.