HYPOTHESIS: Local application of recombinant human insulin-like growth factor 1 (rhIGF-1) via a biodegradable hydrogel after onset of noise-induced hearing loss (NIHL) can attenuate functional and histologic damage. BACKGROUND: The biodegradable gelatin hydrogel makes a complex with drugs by static electric charges and releases drugs by degradation of gelatin polymers. We previously demonstrated the efficacy of local rhIGF-1 application via hydrogels before noise exposure for prevention of NIHL. METHODS: First, we used an enzyme-linked immunosorbent assay to measure human IGF-1 concentrations in the cochlear fluid after placing a hydrogel containing rhIGF-1 onto the round window membrane of guinea pigs. Second, the functionality and the histology of guinea pig cochleae treated with local rhIGF-1 application at different concentrations after noise exposure were examined. Control animals were treated with a hydrogel immersed in physiologic saline alone. RESULTS: The results revealed sustained delivery of rhIGF-1 into the cochlear fluid via the hydrogel. The measurement of auditory brainstem responses demonstrated that local rhIGF-1 treatment significantly reduced the threshold elevation from noise. Histologic analysis exhibited increased survival of outer hair cells by local rhIGF-1 application through the hydrogel. CONCLUSION: These findings indicate that local rhIGF-1 treatment via gelatin hydrogels is effective for treatment of NIHL.
HYPOTHESIS: Local application of recombinant humaninsulin-like growth factor 1 (rhIGF-1) via a biodegradable hydrogel after onset of noise-induced hearing loss (NIHL) can attenuate functional and histologic damage. BACKGROUND: The biodegradable gelatin hydrogel makes a complex with drugs by static electric charges and releases drugs by degradation of gelatin polymers. We previously demonstrated the efficacy of local rhIGF-1 application via hydrogels before noise exposure for prevention of NIHL. METHODS: First, we used an enzyme-linked immunosorbent assay to measure humanIGF-1 concentrations in the cochlear fluid after placing a hydrogel containing rhIGF-1 onto the round window membrane of guinea pigs. Second, the functionality and the histology of guinea pig cochleae treated with local rhIGF-1 application at different concentrations after noise exposure were examined. Control animals were treated with a hydrogel immersed in physiologic saline alone. RESULTS: The results revealed sustained delivery of rhIGF-1 into the cochlear fluid via the hydrogel. The measurement of auditory brainstem responses demonstrated that local rhIGF-1 treatment significantly reduced the threshold elevation from noise. Histologic analysis exhibited increased survival of outer hair cells by local rhIGF-1 application through the hydrogel. CONCLUSION: These findings indicate that local rhIGF-1 treatment via gelatin hydrogels is effective for treatment of NIHL.
Authors: Seiji B Shibata; Sarah R Cortez; James A Wiler; Donald L Swiderski; Yehoash Raphael Journal: Hum Gene Ther Date: 2012-02-08 Impact factor: 5.695
Authors: Andrew A McCall; Erin E Leary Swan; Jeffrey T Borenstein; William F Sewell; Sharon G Kujawa; Michael J McKenna Journal: Ear Hear Date: 2010-04 Impact factor: 3.570
Authors: Jeffrey L Hendricks; Jennifer A Chikar; Mark A Crumling; Yehoash Raphael; David C Martin Journal: Hear Res Date: 2008-06-07 Impact factor: 3.208