Keratin and hyaluronic acid-based microneedle patches with hop extract: An alternative strategy in oral ulcer treatment.

Oral ulcers are a prevalent manifestation of various oral diseases, often resulting in notable pain and discomfort, potentially leading to infection or even malignancy without proper intervention. However, the effectiveness of local therapeutic drugs is limited owing to their short residence time in the oral cavity, with the unique environment such as saliva flow and mechanical actions of lips and tongue, leading to difficulty in penetrating the mucosal and pseudomembrane barriers. Herein, keratin and hyaluronic acid-based microneedle patches loaded with hop extract (KMNs@HE) have been developed for the treatment of oral ulcers. The prepared microneedle patches exhibit a well-arranged microarray and good mechanical properties, which successfully penetrate the pseudomembrane barrier of buccal mucosa ulcer of SD rats. It also shows good antimicrobial activity, acceptable biocompatibility, with a sustained release profile of hop extract for 12 h. Histopathological analysis reveals that the KMNs@HE promotes collagen formation and ameliorates inflammation by downregulating the protein expression of TNF-α and IL-6, thereby accelerating the healing process in the SD rat ulcer model. The developed KMNs@HE has the potential to enhance the comfort and effectiveness of oral ulcer treatment, offering a promising avenue for future research in the treatment of oral mucosal diseases.