Distribution of PLGA nanoparticles in chinchilla cochleae.
OBJECTIVE
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).


METHODS
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 After 40 minutes of PLGA-NP placement on the RWM, perilymph was withdrawn from the scala tympani.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.


RESULTS
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.


CONCLUSIONS
The nanoparticles were distributed throughout the inner ear after application on the chinchilla RWM, with and without magnetic forces.


CONCLUSIONS
PLGA-NP applied to the RWM may have potential for sustained therapy to the inner ear.
Ge
Xianxi
X
Spatial Orientation Center, Department of Otolaryngology, Naval Medical Center San Diego, San Diego, CA 92134-5000, USA. xge@nmcsd.med.navy.mil
Jackson
Ronald L
RL
Liu
Jianzhong
J
Harper
Elizabeth A
EA
Hoffer
Michael E
ME
Wassel
Ronald A
RA
Dormer
Kenneth J
KJ
Kopke
Richard D
RD
Balough
Ben J
BJ
D000818:Animals; D001489:Basilar Membrane / Q000378:metabolism / Q000648:ultrastructure; D001672:Biocompatible Materials / Q000493:pharmacokinetics*; D002682:Chinchilla; D003051:Cochlea / Q000378:metabolism* / Q000648:ultrastructure; D003053:Cochlear Duct / Q000378:metabolism / Q000648:ultrastructure; D003911:Dextrans; D004710:Endolymph / Q000378:metabolism; D005290:Ferric Compounds / Q000493:pharmacokinetics; D052203:Ferrosoferric Oxide / Q000493:pharmacokinetics; D007202:Indicators and Reagents / Q000493:pharmacokinetics; D007501:Iron / Q000493:pharmacokinetics; D019344:Lactic Acid / Q000493:pharmacokinetics*; D008280:Magnetics; D058185:Magnetite Nanoparticles; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D009925:Organ of Corti / Q000378:metabolism / Q000648:ultrastructure; D010087:Oxides / Q000493:pharmacokinetics; D010498:Perilymph / Q000378:metabolism; D011100:Polyglycolic Acid / Q000493:pharmacokinetics*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000493:pharmacokinetics*; D012405:Round Window, Ear / Q000378:metabolism / Q000648:ultrastructure
D001672:Biocompatible Materials; D003911:Dextrans; D005290:Ferric Compounds; D007202:Indicators and Reagents; D058185:Magnetite Nanoparticles; D010087:Oxides; D011108:Polymers; C000499:ferric oxide; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide