Insulin-like growth factor 1 treatment via hydrogels rescues cochlear hair cells from ischemic injury.

This study was designed to investigate the protective effects of recombinant human insulin-like growth factor I (rhIGFI), applied locally via a hydrogel, against ischemic damage of the cochleae in gerbils. A hydrogel was immersed in rhIGFI or saline and was applied on the round window membrane 30 min after the ischemia. Local rhIGFI treatment significantly reduced the elevation of auditory brain responses thresholds at a frequency of 8kHz on days 1, 4, and 7 after ischemia. A histological analysis revealed increased survival of inner hair cells in the animals treated with rhIGFI via the hydrogel 7 days after ischemia. These findings showed that local rhIGFI application using a hydrogel has the potential to protect the cochleae from ischemic injury. NeuroReport 19:1585-1588 (C) 2008 Wolters Kluwer Health Lippincott Williams & Wilkins.