Multifunctional self-healing and pH-responsive hydrogel dressing based on cationic guar gum and hyaluronic acid for on-demand drug release.

Pathogen invasion and persistent inflammatory storms caused by bacterial infections are the main challenges to the healing of infected wounds. Herein, this study proposed a pH-responsive polysaccharide hydrogel dressing (CG-HA) composed of cationic guar gum (CG) and hyaluronic acid (HA). Additionally, Zn and ferulic acid (FA)/β-cyclodextrin (β-CD) inclusion complexes (FA/β-CD) were co-introduced into the CG-HA hydrogel to form the desired FA/β-CD@CG-HA-Zn hydrogel. The FA/β-CD@CG-HA-Zn hydrogel was constructed based on multiple non-covalent interactions, including electrostatic interactions, coordination bonds and hydrogen bonds, allowing it to conform to irregular wound shapes. Notably, the release rates of FA and Zn at pH 7.5 were faster than those at pH 5.5, indicating that the FA/β-CD@CG-HA-Zn hydrogel exhibited excellent pH responsiveness and enabled intelligent drug release. Moreover, the inclusion of FA and Zn endowed the hydrogel with robust antibacterial activity against S. aureus (97 %), MRSA (94 %), and E. coli (95 %). Finally, the FA/β-CD@CG-HA-Zn hydrogel demonstrated efficacy in promoting wound healing by modulating the immune microenvironment and accelerating vascularization. Thus, the developed self-healing FA/β-CD@CG-HA-Zn hydrogel with pH-triggered on-demand drug release is a promising wound dressing for the management of infected wounds.