title: Visualization and analysis of superparamagnetic iron oxide nanoparticles in the inner ear by light microscopy and energy filtered TEM.
abstract: Nanoparticles as potential carriers for local drug transfer are an alternative to systemic drug delivery into the inner ear. We report on the first in vitro tests of a new ferrogel consisting of superparamagnetic iron oxide nanoparticles (SPIONs) and a Pluronic(®) F127 (PF127) copolymer. Pluronic copolymers possess a unique viscosity-adjustable property that makes PF127 gels easy to handle compared to conventional cross-linked hydrogels. This ferrogel was successfully tested in cadaver human temporal bones as well as in organotypic explant cultures of mouse inner ears. SPIONs were identified by light microscopy and localized with different imaging modes in energy-filtered transmission electron microscopy. Our approach shows a promising possibility to use iron oxide nanoparticles, which are suitable for visualization and characterization at both the light- and electron-microscopic levels.
  
  
  BACKGROUND
  The authors report the first in vitro tests of a new ferrogel consisting of superparamagnetic iron oxide nanoparticles (SPIONs) and a Pluronic® F127 (PF127) copolymer for drug delivery in the inner ear, demonstrasting a promising possibility to use iron oxide nanoparticles, which are suitable for visualization and characterization at both the light- and electron-microscopic levels.
authors.affiliation: Carl Zeiss NTS GmbH, Oberkochen, Germany.
authors.forename: Marlene
authors.initials: M
authors.lastname: Thaler
authors.forename: Soumen
authors.initials: S
authors.lastname: Roy
authors.forename: Andrea
authors.initials: A
authors.lastname: Fornara
authors.forename: Mario
authors.initials: M
authors.lastname: Bitsche
authors.forename: Jian
authors.initials: J
authors.lastname: Qin
authors.forename: Mamoun
authors.initials: M
authors.lastname: Muhammed
authors.forename: Willi
authors.initials: W
authors.lastname: Salvenmoser
authors.forename: Gunde
authors.initials: G
authors.lastname: Rieger
authors.forename: Anneliese Schrott
authors.initials: AS
authors.lastname: Fischer
authors.forename: Rudolf
authors.initials: R
authors.lastname: Glueckert
mesh_terms: D000818:Animals; D007758:Ear, Inner / Q000166:cytology* / Q000648:ultrastructure*; D011992:Endosomes / Q000648:ultrastructure; D005290:Ferric Compounds / Q000032:analysis*; D005295:Ferrocyanides; D006801:Humans; D058185:Magnetite Nanoparticles / Q000032:analysis* / Q000648:ultrastructure*; D051379:Mice; D008810:Mice, Inbred C57BL; D046032:Microscopy, Energy-Filtering Transmission Electron / Q000379:methods*; D009924:Organ Culture Techniques; D051381:Rats
chemical_list: D005290:Ferric Compounds; D005295:Ferrocyanides; D058185:Magnetite Nanoparticles; C000499:ferric oxide; C000170:ferric ferrocyanide