Orodispersible hyaluronic acid film delivery for oral wound healing in rats

Background/purpose: Oral wound healing undergoes a dynamic process of oral environment. This study aimed to investigate the effects of hyaluronic acid (HA) film on oral wound healing in a rat model. Materials and methods: A total of 60 rats with tongue wounds (5 mm in diameter) were randomly divided into control (n = 20), HA gel (n = 20), and HA film groups (n = 20). The an-imals were sacrificed on either 3 or 7 days after the experiment. Clinical, histological, and quantitative reverse transcriptase-polymerase chain reaction analysis were performed to eval-uate the healing rate, inflammation, re-epithelialization, and gene expression of wound heal-ing biomarkers. Results: The healing rates of HA gel (84.4 +/- 9.2%) and HA film (74.0 +/- 15.0%) were significantly higher than that of the control (51.7 +/- 16.9%) on day 7 (P < 0.001 and P = 0.002, respectively). Histological analysis revealed no significant differences between the groups on day 3. On day 7, only the HA film showed significant improvement in inflammation (P = 0.038) and re-epithelialization (P = 0.011) compared to the control. Regarding wound healing biomarkers, both HA gel and HA film groups showed lower level of COL1a1 expression on day 3 compared to the control. Conclusion: Within the limits of this study, HA film was found to be effective for oral wound healing, particularly for re-epithelialization. This finding suggests that HA film delivery can be beneficial not only for clinical convenience but also for promoting oral wound healing.(c) 2022 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).