Fotolagen

Fotolagen is a term found in some European science texts to refer to light-activated, collagen- or gelatin-based hydrogels used in biomedicine and tissue engineering. These materials are typically produced by chemically modifying collagen or gelatin with photoreactive groups, enabling crosslinking when irradiated with light in the presence of a photoinitiator. The resulting hydrogel forms a three-dimensional network whose mechanical and biochemical properties can be tuned by the polymer concentration, degree of substitution, and light dose.

Chemistry and processing: Common approaches include the methacrylation of gelatin to yield GelMA, which can be crosslinked with UV or visible light using photoinitiators such as Irgacure 2959 or lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP). Some systems use visible-light initiators to reduce cellular damage. The materials are often injectable or suitable for 3D bioprinting.

Applications: Fotolagen hydrogels are used for cell encapsulation, tissue engineering scaffolds, wound dressings, organ-on-a-chip models, and drug screening, due to their biocompatibility and tunable degradation.

Limitations: Potential cytotoxicity of initiators, light-induced damage to cells, and swelling or mechanical instability in physiologic conditions. Standardization of naming and properties varies; more precise terms such as photocrosslinkable gelatin or GelMA are preferred in many contexts.

See also: GelMA, photocrosslinkable hydrogels, photopolymerization.

References: Not included here; this is a general overview and readers should consult current literature on photocrosslinkable collagen-based hydrogels for specific details.