Effects of local application of methylprednisolone delivered by the C/GP-hydrogel on the recovery of facial nerves

Conclusions: Local administration of MP delivered by the C/GP-MP-hydrogel can improve the recovery of facial nerve following crush injury. The findings suggested that locally injected MP delivered by C/GP-hydrogel might be a promising treatment for facial nerve damage. Objectives: In this study, the aim is to assess the effectiveness of locally administrating methylprednisolone(MP) loaded by chitosan-β-glycerophosphate hydrogel (C/GP-hydrogel) on the regeneration of facial nerve crush injury. Methods: After the crush of left facial nerves, Wistar rats were randomly divided into four different groups. Then, four different therapies were used to treat the damaged facial nerves. At the 1^st, 2^nd, 3^rd, and 4^th week after injury, the functional recovery of facial nerves and the morphological changes of facial nerves were assessed. The expression of growth associated protein-43 (GAP-43) protein in the facial nucleus were also evaluated. Results: Locally injected MP delivered by C/GP-hydrogel effectively accelerated the facial functional recovery. In addition, the regenerated facial nerves in the C/GP-MP group were more mature than those in the other groups. The expression of GAP-43 protein was also improved by the MP, especially in the C/GP-MP group.