Tuning Superfast Curing Thiol?Norbornene?Functionalized Gelatin Hydrogels for 3D Bioprinting

Photocurable gelatin-based hydrogels have established themselves as powerful bioinks in tissue engineering due to their excellent biocompatibility, biodegradability, light responsiveness, thermosensitivity and bioprinting properties. While gelatin methacryloyl (GelMA) has been the gold standard for many years, thiol-ene hydrogel systems based on norbornene-functionalized (GelNB) a thiolated crosslinker recently gained increasing importance. In this paper, highly reproducible water-based synthesis of GelNB is presented, avoiding use dimethyl sulfoxide (DMSO) organic solvent covering broad range degrees functionalization (DoF: 20% 97%). Mixing with (GelS) results superfast curing photoclick GelNB/GelS. Its superior properties over GelMA, such substantially reduced amounts photoinitiator (0.03% (w/v)), (1–2 s), higher network homogeneity, post-polymerization ability, minimal cross-reactivity cellular components, improved biocompatibility precursors degradation products lead increased survival primary cells 3D bioprinting. Post-printing viability analysis revealed rates > 84% GelNB/GelS varying crosslinking density, while cell GelMA strongly dependent DoF. Hence, semisynthetic easily accessible promising bioink future medical applications other light-based biofabrication techniques.