Distribution of PLGA nanoparticles in chinchilla cochleae

2007 ◽  
Vol 137 (4) ◽  
pp. 619-623 ◽  
Author(s):  
Xianxi Ge ◽  
Ronald L. Jackson ◽  
Jianzhong Liu ◽  
Elizabeth A. Harper ◽  
Michael E. Hoffer ◽  
...  
Keyword(s):  
Inner Ear ◽  
Round Window ◽  
Organ Of Corti ◽  
Plga Nanoparticles ◽  
Round Window Membrane ◽  
Scala Tympani ◽  
Magnetic Forces ◽  
Magnetic Exposure ◽  
Transmission Electron ◽  
Electron Energy Loss

Objectives 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). Study Design and Setting Six chinchillas (12 ears) were equally divided into controls (no treatments) and experimen-tals (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 After 40 minutes of PLGA-NP placement on the RWM, perilymph was withdrawn from the scala tympani.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. Conclusion The nanoparticles were distributed throughout the inner ear after application on the chinchilla RWM, with and without magnetic forces. Significance PLGA-NP applied to the RWM may have potential for sustained therapy to the inner ear.

scholarly journals Understanding the translocation mechanism of PLGA nanoparticles across round window membrane into the inner ear: a guideline for inner ear drug delivery based on nanomedicine

2018 ◽  
Vol Volume 13 ◽  
pp. 479-492 ◽  
Author(s):  
Liping Zhang ◽  
Yuan Xu ◽  
Wenjuan Cao ◽  
Shibao Xie ◽  
Lu Wen ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Inner Ear ◽  
Round Window ◽  
Plga Nanoparticles ◽  
Round Window Membrane ◽  
Translocation Mechanism

Inner Ear Damage and Passage through the round Window Membrane of Pseudomonas Aeruginosa Exotoxin a in a Chinchilla Model

1992 ◽  
Vol 101 (5) ◽  
pp. 437-444 ◽  
Author(s):  
Lars Lundman ◽  
Teruhiko Harada ◽  
Peter A. Santi ◽  
Steven K. Juhn ◽  
Tetsuo Morizono ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inner Ear ◽  
Round Window ◽  
Organ Of Corti ◽  
Round Window Membrane ◽  
Enzyme Linked Immunosorbent Assay ◽  
Computer Assisted ◽  
Exotoxin A ◽  
Inner Ear Damage ◽  
Pseudomonas Aeruginosa Exotoxin

By the use of computer-assisted morphometric analysis of the organ of Corti and/or measurements of action potential threshold changes, inner ear changes in chinchillas were evaluated 4 weeks after application on the round window membrane of a Pseudomonas aeruginosa exotoxin A solution. Severe inner ear damage was detected after application of 50 ng (5 μL at a concentration of 10 μg/mL) exotoxin A, whereas application of 5 ng exotoxin did not cause measurable inner ear damage. Perilymph concentrations of exotoxin A were measured with an enzyme-linked immunosorbent assay 1.5 to 19 hours after 50 ng, 0.5 μg, or 5 μg of exotoxin A was applied on the round window membrane. Only the highest concentration produced measurable levels of exotoxin in the inner ear fluids. It is concluded that exotoxin A present on the round window membrane of the chinchilla has the ability to penetrate into the inner ear and cause irreversible inner ear changes.

scholarly journals Analysis of the Damage Mechanism Related to CO2 Laser Cochleostomy on Guinea Pig Cochlea

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiang Liu ◽  
Xiao-qing Qian ◽  
Rui Ma ◽  
Fang-Lu Chi ◽  
Dong-Dong Ren
Keyword(s):  
Guinea Pig ◽  
Inner Ear ◽  
Round Window ◽  
Organ Of Corti ◽  
Damage Mechanism ◽  
Round Window Membrane ◽  
Control Group ◽  
Guinea Pig Cochlea ◽  
Brainstem Response ◽  
Laser Induced Damage

Different types of lasers have been used in inner ear surgery. Therefore, it is of the utmost importance to avoid damage to the inner ear (e.g., hyperthermia and acoustic effects) caused by the use of such lasers. The aim of this study was to use a high powered fibre-enabled CO2 laser (10 W, 606 J/cm2) to perform cochleostomies on guinea pig cochlea and to investigate the possible laser-induced damage mechanisms. The temperature changes in the round window membrane, auditory evoked brainstem response, and morphological of the hair cells were measured and recorded before and after laser application. All of the outcomes differed in comparison with the control group. A rise in temperature and subsequent increased hearing loss were observed in animals that underwent surgery with a 10 W CO2 laser. These findings correlated with increased injury to the cochlear ultrastructure and a higher positive expression of E-cadherin and β-catenin in the damaged organ of Corti. We assume that enhanced cell-cell adhesion and the activated β-catenin-related canonical Wnt-signalling pathway may play a role in the protection of the cochlea to prevent further damage.

scholarly journals Cutaneous and Labyrinthine Tolerance of Bioactive Glass S53P4 in Mastoid and Epitympanic Obliteration Surgery: Prospective Clinical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Daniele Bernardeschi ◽  
Yann Nguyen ◽  
Francesca Yoshie Russo ◽  
Isabelle Mosnier ◽  
Evelyne Ferrary ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Inner Ear ◽  
Round Window ◽  
Bone Conduction ◽  
Hearing Threshold ◽  
Round Window Membrane ◽  
Prospective Clinical Study ◽  
Local Skin ◽  
Local Skin Reaction ◽  
Bone Conduction Hearing

Objective. To evaluate the cutaneous and the inner ear tolerance of bioactive glass S53P4 when used in the mastoid and epitympanic obliteration for chronic otitis surgery.Material and Methods. Forty-one cases have been included in this prospective study. Cutaneous tolerance was clinically evaluated 1 week, 1 month, and 3 months after surgery with a physical examination of the retroauricular and external auditory canal (EAC) skin and the presence of otalgia; the inner ear tolerance was assessed by bone-conduction hearing threshold 1 day after surgery and by the presence of vertigo or imbalance.Results. All surgeries but 1 were uneventful: all patients maintained the preoperative bone-conduction hearing threshold except for one case in which the round window membrane was opened during the dissection of the cholesteatoma in the hypotympanum and this led to a dead ear. No dizziness or vertigo was reported. Three months after surgery, healing was achieved in all cases with a healthy painless skin. No cases of revision surgery for removal of the granules occurred in this study.Conclusion. The bioactive glass S53P4 is a well-tolerated biomaterial for primary or revision chronic otitis surgery, as shown by the local skin reaction which lasted less than 3 months and by the absence of labyrinthine complications.

Inner Ear Pathology and Otitis Media

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 249-253 ◽  
Author(s):  
Michael M. Paparella ◽  
Marcos V. Goycoolea ◽  
William L. Meyerhoff
Keyword(s):  
Inner Ear ◽  
Otitis Media ◽  
Round Window ◽  
Round Window Membrane

Insidious inner ear complications of otitis media have been and are being studied in our laboratory. The purpose of this paper is to review these studies, coordinate, capsulize and highlight the results with emphasis on the transport role of the round window membrane.

Eradicating Otomycosis with Terbinafine Solution: Basic and Clinical Investigation

2019 ◽  
Vol 24 (4) ◽  
pp. 183-190
Author(s):  
Ting-Hua Yang ◽  
Yi-Ho Young
Keyword(s):  
Clinical Practice ◽  
Inner Ear ◽  
Morphological Study ◽  
Antifungal Agents ◽  
Clinical Investigation ◽  
Round Window ◽  
Round Window Membrane ◽  
Potential Candidate ◽  
Potential Treatment ◽  
Total Dosage

Background: Otomycosis still remains intractable in clinical practice, likely because topical antifungal agents lack efficacy or are potentially toxic to the inner ear end organs. Objectives: The aim of this study was to investigate whether terbinafine solution is a potential candidate for treating intractable otomycosis in humans. In addition, the toxic effect on the inner ear was also assessed by animal models treated with terbinafine. Methods: Guinea pigs were instilled with 0.1 mL terbinafine (10 and 25 mg/mL) in the left round window membrane. At 2 weeks after treatment, all animals underwent an inner ear test battery and were then sacrificed for morphological study. Clinically, 20 patients with otomycosis were treated with terbinafine solution at a dosage of 0.4 mg. Results: All terbinafine-treated animals showed intact inner ear function when total dosage of terbinafine was <2.5 mg, which was further confirmed by morphological study. Subsidence of otomycosis was achieved in all 20 patients 1 week after treatment with terbinafine (0.4 mg) without untoward effect. No evidence of recurrence was noted 1 year after treatment. Conclusion: The paucity of inner ear toxicity of terbinafine even at a dosage of 2.5 mg was identified in guinea pig models morphologically and physiologically. Topical application of terbinafine solution at a dosage of 0.4 mg may be a potential treatment for otomycosis in humans.

Intratympanic Steroid Treatment of Inner Ear Disease and Tinnitus (Preliminary Report)

1996 ◽  
Vol 75 (8) ◽  
pp. 468-488 ◽  
Author(s):  
Herbert Silverstein ◽  
Daniel Choo ◽  
Seth I. Rosenberg ◽  
Jeffery Kuhn ◽  
Michael Seidman ◽  
...  
Keyword(s):  
Inner Ear ◽  
Round Window ◽  
Meniere’S Disease ◽  
Menière’S Disease ◽  
Round Window Membrane ◽  
Meniere's Disease ◽  
Ménière’S Disease ◽  
Menière's Disease ◽  
Inner Ear Disease ◽  
Ménière's Disease

Intratympanic instillation of Depo-Medrol® (80 mg/cc), dexamethasone ophthalmic solution (1 mg/cc), or dexamethasone intravenous (4 mg/cc) solution produces improvement of cochlear function in certain patients with Meniere's disease, autoimmune inner ear disease and sudden sensorineural deafness. Tinnitus improved in 47%, most often in patients with Meniere's disease (9 of 15; 60%). The SRT improvement of greater than 10 dB or SD greater than 15% was documented in 41% (average improvement in SRT: 15 dB; SD: 24%). Patients with tinnitus and bilateral sensorineural hearing loss (i.e., presbycusis) did not benefit from the treatment. Prior to treatment with intratympanic medication, laser-assisted tympanostomy with middle ear exploration, using otoendoscopy to determine the status of the round window niche and remove mucosal folds, helps in making the round window membrane accessible to local application of drops. Placing Gelfoam into the round window niche under direct vision, and using a Venturi Bobbin tube in the tympanic membrane, appears to be a satisfactory method for delivering medication to the inner ear fluids. The medication can be injected by the physician through the tube into the middle ear, or the patient can perform self-treatment at home, placing medication in the external auditory canal. A double-blind, cross-over study in patients with Meniere's disease is now in progress with Institutional Review Board (IRB) approval, which will be reported at a later date. This preliminary study has shown that intratympanic steroids may affect the symptoms of hearing loss and tinnitus in patients with various inner ear problems. Patients with Meniere's disease appear to respond in the highest percentage of cases. Hopefully, additional research will suggest the appropriate drugs which can be used to treat inner ear disease. Direct application of the drug to the round window membrane may increase the concentration in the inner ear fluids, thus avoiding the systemic effects.

Inner ear biocompatibility of lipid nanocapsules after round window membrane application

2011 ◽  
Vol 404 (1-2) ◽  
pp. 211-219 ◽  
Author(s):  
Ya Zhang ◽  
Weikai Zhang ◽  
Marian Löbler ◽  
Klaus-Peter Schmitz ◽  
Patrick Saulnier ◽  
...  
Keyword(s):  
Inner Ear ◽  
Round Window ◽  
Round Window Membrane ◽  
Lipid Nanocapsules

scholarly journals Effect of oxygen-flooding to the round window membrane on the inner ear function of the anoxic cochlea.

1986 ◽  
Vol 79 (7) ◽  
pp. 1143-1147
Author(s):  
Toshimitsu KOBAYASHI ◽  
Takuji OKITSU ◽  
Katsuhisa IKEDA ◽  
Jun KUSAKARI
Keyword(s):  
Inner Ear ◽  
Round Window ◽  
Round Window Membrane ◽  
Effect Of Oxygen

Rupture of the Round Window Membrane in Inner Ear Barotrauma

1974 ◽  
Vol 99 (6) ◽  
pp. 437-442 ◽  
Author(s):  
P. Freeman ◽  
J. Tonkin ◽  
C. Edmonds
Keyword(s):  
Inner Ear ◽  
Round Window ◽  
Round Window Membrane ◽  
Inner Ear Barotrauma
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