Customizable hydrospongel based on chitosan microfibers.

Customizable and viscoelastic porous biomaterials are highly desired as implant scaffold for repairing large-volume defects. Herein, we report customizable chitosan microfibers (CMFs)-based hydrospongels with mechanical properties comparable to soft tissues. The CMFs formed under high-speed shearing during crystallization of chitosan, and then they are crosslinked through covalent bond and hydrogen bond to form hydrospongels. The relatively high rigidity of CMFs provided hydrospongels with bulk elasticity at small deformation like hydrogel, and rapid reabsorb water in porous structures similar to sponge, endows excellent self-recovery property to hydrospongels after a large compression deformation. The optimized hydrospongel chemical crosslinked by glycerol triglycidyl ether (GTE) exhibits rapid recovery (1 s) owing to the synergistic effect of strong covalent and hydrogen bonds in porous structure. CMFs suspension has obvious shearing thinning property and can self-support its architecture after extrusion, realizing customizable capability to fabricate various 2D and 3D architectures. In vitro hemolysis test, cell test and CCK-8 assay demonstrate that hydrospongel has excellent hemocompatibility, cytocompatibility and non-toxicity. In vivo subcutaneous implantation of hydrospongel in rats reveal biodegradability and no inflammatory reaction. These properties provide a facile approach to fabricate green and mass-producible hydrospongel as an implant scaffold for biomedical applications.