Scientists from the University of Wuerzberg in Germany and the University of Otago Christchurch in New Zealand conducted an in-depth analysis of GelAGE synthesis. Standard UV-initiation was further compared with a recently described visible-light-initiator system for GelAGE hydrogel formation.
The study, conducted by Sarah Bertlein, Gabriella Brown, Khoon S. Lim, Tomasz Jungst, Thomas Boeck, Torsten Blunk, Joerg Tessmar, Gary J. Hooper and Tim B. F. Woodfield, demonstrated that GelAGE may serve as a platform bioink for several biofabrication technologies by fabricating constructs with high shape fidelity via lithography-based (digital light processing) 3D printing and extrusion-based 3D bioprinting, the latter supporting long-term viability postprinting of encapsulated chondrocytes.
Bioprinting can be defined as the art of combining materials and cells to fabricate designed, hierarchical 3D hybrid constructs. Suitable materials, so called bioinks, have to comply with challenging rheological processing demands and rapidly form a stable hydrogel postprinting in a cytocompatible manner.
Gelatin is often adopted for this purpose, usually modified with (meth-)acryloyl functionalities for postfabrication curing by free radical photopolymerization, resulting in a hydrogel that is cross-linked via nondegradable polymer chains of uncontrolled length.
The application of allylated gelatin (GelAGE) as a thiol–ene clickable bioink for distinct biofabrication applications is reported. Curing of this system occurs via dimerization and yields a network with flexible properties that offer a wider biofabrication window than (meth-)acryloyl chemistry, and without additional nondegradable components.