Distribution of PLGA nanoparticles in chinchilla cochleae

• Published in: Otolaryngology-head and neck surgery 2007-10, Vol.137 (4), p.619-623
• Main Authors: Ge, Xianxi, Jackson, Ronald L., Liu, Jianzhong, Harper, Elizabeth A., Hoffer, Michael E., Wassel, Ronald A., Dormer, Kenneth J., Kopke, Richard D., Balough, Ben J.
• Format: Article
• Language: English
• Subjects: Animals; Basilar Membrane - metabolism; Basilar Membrane - ultrastructure; Biocompatible Materials - pharmacokinetics; Chinchilla; Cochlea - metabolism; Cochlea - ultrastructure; Cochlear Duct - metabolism; Cochlear Duct - ultrastructure; Dextrans; Endolymph - metabolism; Ferric Compounds - pharmacokinetics; Ferrosoferric Oxide - pharmacokinetics; Indicators and Reagents - pharmacokinetics; Iron - pharmacokinetics; Lactic Acid - pharmacokinetics; Magnetics; Magnetite Nanoparticles; Microscopy, Electron, Transmission; Nanoparticles; Organ of Corti - metabolism; Organ of Corti - ultrastructure; Oxides - pharmacokinetics; Perilymph - metabolism; Polyglycolic Acid - pharmacokinetics; Polymers - pharmacokinetics; Round Window, Ear - metabolism; Round Window, Ear - ultrastructure
• ISSN: 0194-5998; 1097-6817
• DOI: 10.1016/j.otohns.2007.04.013

To study the distribution of polylactic/glycolic acid–encapsulated iron oxide nanoparticles (PLGA-NPs) in chinchilla cochleae after application on the round window membrane (RWM). Six chinchillas (12 ears) were equally divided into controls (no treatments) and experimentals (PLGA-NP with or without magnetic exposure). After 40 minutes of PLGA-NP placement on the RWM, perilymph was withdrawn from the scala tympani. The RWM and cochleae were fixed with 2.5% glutaraldehyde and processed for transmission electron microscopy. Nanoparticles were found in cochleae with or without exposure to magnet forces appearing in the RWM, perilymph, endolymph, and multiple locations in the organ of Corti. Electron energy loss spectroscopy confirmed iron elements in nanoparticles. The nanoparticles were distributed throughout the inner ear after application on the chinchilla RWM, with and without magnetic forces. PLGA-NP applied to the RWM may have potential for sustained therapy to the inner ear.