Antibacterial antioxidant polyurethane/curcumin patch with anti-swelling ability for tissue adhesion and treatment of oral ulcers

Oral ulcers severely affect the patient’s mood, diet, and language activities and are mainly treated by topical administration of a patch. However, the currently commercially available patches have a limited treatment effect because of the short action time in the oral cavity. In this study, we present a novel adhesive patch made from trifunctional polycaprolactone crosslinked waterborne polyurethane (CDCPU) loaded with curcumin for treating oral ulcers. The long-chain triol cross-linking points in the polyurethane can limit water entry, while stabilizing the curcumin loading in the emulsion. Meanwhile, the interaction between curcumin and polyurethane improved the anti-swelling (swelling rate of 37.7 ± 4.9 %), water resistance (water absorption rate of 66.6 ± 5.6 %), and mechanical properties of the patch. The adhesion strength of the CDCPU patch to porcine oral mucosa and skin was 11.3 ± 1.7 kPa and 14.7 ± 2.5 kPa, respectively. The addition of curcumin provides the CDCPU patch with effective antibacterial and antioxidant functions. Moreover, the CDCPU patch was effective in promoting mucosal epithelialization and ulcer healing in a rat oral ulcer model. The development of this adhesive patch provides a new strategy for the treatment of oral ulcers.