Genipin-crosslinked pectin hydrogels: A dual strategy for enhanced 3D printability and stability

The development of polysaccharide-based biomaterial inks with tailored physicochemical properties and dynamic responsiveness currently attracts a lot of scientific interest. Pectin, a natural and biocompatible polysaccharide, shows great promise for a wide range of biomedical applications, but its limited mechanical strength and printability constrain its application in 3D extrusion bioprinting. This study introduces a strategy to overcome these drawbacks via amine modification and genipin crosslinking, producing hydrogels with improved mechanical stability under physiological conditions. Pectin hydrogels formed at various amine:genipin ratios (1:0.6 to 1:3) exhibited elastic moduli values in the range of 3-5 KPa under physiological conditions, with crosslinking efficiency reaching a plateau. Biomaterial inks comprising crosslinked pectin particles were dispersed in a reactive aqueous pectin solution, thus enabling precise 3D extrusion of scaffolds with up to 7 layers, maintaining structural integrity post-lyophilization. The 3D printed pectin hydrogels showed enhanced porosity and swelling kinetics, particularly in response to pH changes, while maintaining high hydrolytic stability and non-cytotoxicity. This approach provides a promising platform for developing dynamic, pectin-based bioinks in bio applications requiring of extrusion based additive manufacturing techniques.