Facile Fabrication of Biocompatible Gelatin-Based Self-Healing Hydrogels

The self-healing hydrogels are extremely attractive in biological and biomedical fields. The imine bond obtained by the Schiff base reaction is a commonly used dynamic covalent bond to fabricate self-healing hydrogels. Gelatin is a commonly used natural macromolecule in the biomedical field with excellent biocompatibility, biodegradability, and nonimmunogenicity. However, the gelatin-based hydrogels with self-healing ability are rarely reported based on imine bonds. Herein, we present a facile approach to fabricate a gelatin hydrogel with self-healing ability based on the Schiff base reaction. The gelatin was first reacted with ethylenediamine to increase the content of amino groups. Then dialdehyde carboxymethyl cellulose was used to cross-link amino-gelatin to fabricate the self-healing hydrogel. The results showed that the fabricated hydrogel exhibited good self-healing ability as expected because of the formed dynamic imine bonds between amino-gelatin and dialdehyde carboxymethyl cellulose. The hydrogel also presented good fatigue resistance and self-recovery capacity. Moreover, the self-healing hydrogel possessed ideal hemocompatibility and cytocompatibility. In sum, the fabricated self-healing hydrogel has application prospects in biomedical fields, such as injectable cell and drug carrier and injectable tissue engineering scaffold.