title: Efficient cochlear gene transfection in guinea-pigs with adeno-associated viral vectors by partial digestion of round window membrane.
abstract: The auditory portion of the inner ear, the cochlea, is an ideal organ for local gene transfection owing to its relative isolation. Various carriers have been tested for cochlear gene transfection. To date, viral vectors appear to have much higher transfection efficacy than non-viral mechanisms. Among these vectors, recombinant adeno-associated virus (rAAV) vectors have several advantages such as being non-pathogenic and the ability to produce prolonged gene expression in various cell types. However, rAAV vectors cannot pass through the intact round window membrane (RWM), otherwise a very attractive approach to access the human inner ear. In this study, performed in guinea-pigs, we describe a method to increase the permeability of RWM to rAAV vectors by partial digestion with collagenase solution. Elevated delivery of rAAV across the partially digested RWM increased transfection efficacy to a satisfactory level, even though it was still lower than that achieved by direct cochleostomy injection. Functional tests (auditory brainstem responses) showed that this enzymatic manipulation did not cause permanent hearing loss if applied appropriately. Morphological observations suggested that the damage to RWM caused by partial digestion healed within four weeks. Taken together, these findings suggest that partial digestion of the RWM is a safe and effective method for increasing the transfection of cochlear sensory cells with rAAV.
authors.affiliation: Department of Otolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Murphy
authors.forename: D
authors.initials: D
authors.lastname: Taaffe
authors.forename: S
authors.initials: S
authors.lastname: Yin
authors.forename: L
authors.initials: L
authors.lastname: Xia
authors.forename: W W
authors.initials: WW
authors.lastname: Hauswirth
authors.forename: M
authors.initials: M
authors.lastname: Bance
authors.forename: G S
authors.initials: GS
authors.lastname: Robertson
authors.forename: J
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D003051:Cochlea / Q000378:metabolism*; D000229:Dependovirus / Q000235:genetics / Q000378:metabolism*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism*; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000378:metabolism; D006801:Humans; D008297:Male; D012405:Round Window, Ear / Q000378:metabolism*; D014162:Transfection