Shape memory polyacrylamide/gelatin hydrogel with controllable mechanical and drug release properties potential for wound dressing application

Abstract

In this work, various shape memory polyacrylamide/gelatin (PAM-Gels) hydrogels with interpenetrating double networks were synthesized via a facile one-pot method. Taking advantage of the thermal reversible property of physical gelatin network and the constant of chemical crosslinking polyacrylamide network, the prepared PAM-Gels hydrogels showed shape memory function under warm water. Moreover, the shape memory, mechanical, drug release, and swelling properties of the prepared PAM-Gels hydrogels could be tuned by altering the gelatin component content. Notably, the PAM-Gel5 hydrogel containing 5% w/v of gelatin exhibited the most effective enhancements in physicochemical properties, and the highest shape fixity and shape recovery rate were 78.2% and 93.5%, respectively. Meanwhile, it could retain the integrity of its shape even with high water uptake. More importantly, the PAM-Gel5 hydrogel possessed well balanced mechanical properties (e.g. tensile strength was 0.57 MPa and elongation at break was 1556% in tensile test; compression stress was 0.06 MPa and Young's modulus was 0.38 MPa in compression test) among the as-prepared PAM-Gels hydrogels, due to its uniform pore size distribution and smaller pore size. Furthermore, the drug release experiment revealed that the PAM-Gel5 hydrogel showed sustained release characteristics, and the majority of loaded model drug could be released within 24 h under physiological conditions. Additionally, cytotoxicity test suggested the representative PAM-Gel5 hydrogel exhibited good in vitro cytocompatibility. This work provides a viable avenue for developing bio-compatible shape memory hydrogel with acceptable mechanical and drug release properties applied as wound dressing.