A multifunctional hydrogel based on nature polysaccharide fabricated by Schiff base reaction

A multifunctional hydrogel derived from carboxymethyl chitosan (CMCS) and oxidized hyaluronic acid (OHA), was fabricated by Schiff base reaction between the amino groups of CMCS and aldehyde groups in OHA. The aldehyde groups of OHA were prepared through the oxidation of hydroxy groups of hyaluronic acid (HA) by NaIO4, and the oxidation degree of OHA can be adjusted by varying amount of NaIO4. Furthermore, the gelation time, mechanical strength, swelling and deswelling properties of gels are different with varying the concentration of precursor solution. This hydrogel shows an excellent swelling capacity of 6000 % for the abounded hydroxyl groups in chains. For the dynamic action of Schiff base action, it also showed a good self-healing capacity to be healed in three minutes around 25 degrees C. In addition, OHA-CMCS gel had good water or heating induced shape memory property. Moreover, hydrogels with complex structures were fabricated by 3D printing. In a word, the versatility of OHA-CMCS gel makes it could have a widely application for biomedical and 4D printing applications.