Gelatin-Methacryloyl Bioinks: Gelatin Source, Degree of Functionalisation, Thermal State, Photocure and Cell Response

Gelatin methacryloyl (GelMA) is one of the most widely used photocrosslinkable bioinks, yet the name GelMA hides several material variables that can materially change printing and biological outcomes. Gelatin source and bloom strength influence chain length and thermal gelation; degree of functionalisation controls the density of reactive groups; concentration and temperature define the pre-cure physical state; and photoinitiation determines the conversion history experienced by encapsulated cells. This review treats these variables as a coupled state description. It distinguishes printability gained from reversible gelatin gelation from final network properties created by light, and it emphasises that identical nominal GelMA concentration does not imply identical macromolecular or biological state. A qualification framework is proposed around source identity, functionalisation, thermal history, rheology, spectral dose, conversion, swelling, mechanics and cell response. The central objective is to make GelMA results transferable without assuming that a single concentration and exposure time define the material.

ER-322 · Version 0.5.