Flaherty SM, Russell IJ, Lukashkin AN. Drug distribution along the cochlea is strongly enhanced by low-frequency round window micro vibrations.
Drug Deliv 2021;
28:1312-1320. [PMID:
34176371 PMCID:
PMC8238068 DOI:
10.1080/10717544.2021.1943059]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The cochlea’s inaccessibility and complex nature provide significant challenges to delivering drugs and other agents uniformly, safely and efficiently, along the entire cochlear spiral. Large drug concentration gradients are formed along the cochlea when drugs are administered to the middle ear. This undermines the major goal of attaining therapeutic drug concentration windows along the whole cochlea. Here, utilizing a well-known physiological effect of salicylate, we demonstrate a proof of concept in which drug distribution along the entire cochlea is enhanced by applying round window membrane low-frequency micro vibrations with a probe that only partially covers the round window. We provide evidence of enhanced drug influx into the cochlea and cochlear apical drug distribution without breaching cochlear boundaries. It is further suggested that ossicular functionality is not required for the effective drug distribution we report. The novel method presented here of local drug delivery to the cochlea could be implemented when ossicular functionality is absent or impeded and can be incorporated in clinically approved auditory protheses for patients who suffer with conductive, sensorineural or mixed hearing loss.
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