Direct 3D printing of thermosensitive AOP127-oxidized dextran hydrogel with dual dynamic crosslinking and high toughness

3D printing hydrogel is attractive to fabricate biomimetic scaffolds for skin repair. However, hydrogels that can be directly 3D printed with excellent mechanical properties are still limited. Here, a dual crosslinked hydrogel based on dynamic oxime crosslinking and hydrophobic interaction is developed for direct extrusion printing. We apply aminooxy terminated Pluronic F127 (AOP127) and oxidized dextran (ODex) as materials. At a lower temperature (ca. 16 °C), AOP127 and ODex form hydrogel with oxime binding for extrusion printing. At higher temperature (37 °C), the PPO segments of AOP127 physically associate, forming the second crosslinking to toughen the hydrogel. The hydrogel exhibits excellent thermosensitivity and self-healability. By 3D printing of AOP127-ODex-15% hydrogel, the obtained scaffolds show high toughness and excellent cytocompatibility. After coated with fibroin, the composite constructs showed adhesion and proliferation of skin cells. The present hydrogel is promising for fabrication of tough scaffold with natural polysaccharides and synthetic polymers.