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Updated: May 29, 2026
A Comparative Study of Drug Delivery Methods Targeted to the Mouse Inner Ear: Bullostomy Versus Transtympanic Injection
Published on: March 8, 2017
Comparison of the distribution pattern of PEG-b-PCL polymersomes delivered into the rat inner ear via different
Ya Zhang1, Weikai Zhang, Alexander H Johnston
1Department of Otolaryngology, University of Tampere, Medical school and University Hospital of Tampere, Finland.
Conclusion:
Cochleostomy is the most efficient approach in delivering PEG-b-PCL polymersomes (PMs) to the inner ear. PMs can be delivered to the vestibule by transtympanic injection or cochleostomy.
Objective:
To evaluate the efficiency of delivering PEG-b-PCL PMs into the inner ear using different approaches.
Methods:
The PEG-b-PCL PMs were administered either by sustained topical round window membrane (RWM) delivery using gelatin sponge pledgets in combination with an osmotic pump, transtympanic injection, or cochleostomy. The distribution of the PMs in the inner ear was observed by confocal microscopy using either whole mount specimens or cryosections.
Results:
Cochleostomy resulted in distribution of the PMs in the spiral ligament (SL), mesothelial cells beneath the organ of Corti, supporting cells in the organ of Corti, and spiral ganglion cells (SGCs). Transtympanic injection induced uptake of the PMs in the SL and mesothelial cells beneath the organ of Corti. Topical administration showed distribution of the PMs only in the SL. In the vestibulum, transtympanic injection and cochleostomy induced more distribution of the PMs than did topical RWM delivery (p < 0.05, Kruskal-Wallis test).
