Cochlear gene delivery through an intact round window membrane in mouse

Cochlear gene transfer studies in animal models have utilized mainly two de livery methods: direct injection through the round window membrane (RWM) or intracochlear infusion through a cochleostomy. However, the surgical traum a, inflammation, and hearing loss associated with these methods Lead us to investigate a less invasive delivery method. Herein, we studied the feasibi lity of a vector transgene-soaked gelatin sponge, Gelfoam, for transgene de livery into the mouse cochlea through an intact RWM, The Gelfoam absorbed w ith liposomes and adenovirus, but not with adeno-associated virus (AAV), wa s successful in mediating transgene expression across an intact RWM in a va riety of cochlear tissues. The Gelfoam technique proved to be an easy, atra umatic, and effective, but vector-dependent, method of delivering transgene s through an intact RWM, Compared with the more invasive gene delivery meth ods, this technique represents a safer and a more clinically viable route o f cochlear gene delivery in humans.