Dynamically Cross-Linked Granular Hydrogels for 3D Printing and Therapeutic Delivery

This study developed granular hydrogels with enhanced structural stability through reversible interparticle cross-linking using dynamic covalent bonds. By fragmenting photo-cross-linked bulk hydrogels into aldehyde or hydrazide-functionalized microgels, interparticle cross-linking was achieved via reversible hydrazone bonds. This provided the hydrogels with shear-thinning and self-healing properties, making them suitable for injectability and 3D printing. The resulting hydrogels exhibited high mechanical stability and improved porosity, facilitating sustained release of growth factors and enhanced cell recruitment. The findings demonstrate the potential of these hydrogels as effective biomaterials for tissue engineering and therapeutic delivery scaffolds.