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Bader W, Steinacher C, Fischer HT, Glueckert R, Schmutzhard J, Schrott-Fischer A. Effects of Therapeutic Hypothermia on Macrophages in Mouse Cochlea Explants. Int J Mol Sci 2023; 24:8850. [PMID: 37240196 PMCID: PMC10218374 DOI: 10.3390/ijms24108850] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/04/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Globally, over the next few decades, more than 2.5 billion people will suffer from hearing impairment, including profound hearing loss, and millions could potentially benefit from a cochlea implant. To date, several studies have focused on tissue trauma caused by cochlea implantation. The direct immune reaction in the inner ear after an implantation has not been well studied. Recently, therapeutic hypothermia has been found to positively influence the inflammatory reaction caused by electrode insertion trauma. The present study aimed to evaluate the hypothermic effect on the structure, numbers, function and reactivity of macrophages and microglial cells. Therefore, the distribution and activated forms of macrophages in the cochlea were evaluated in an electrode insertion trauma cochlea culture model in normothermic and mild hypothermic conditions. In 10-day-old mouse cochleae, artificial electrode insertion trauma was inflicted, and then they were cultured for 24 h at 37 °C and 32 °C. The influence of mild hypothermia on macrophages was evaluated using immunostaining of cryosections using antibodies against IBA1, F4/80, CD45 and CD163. A clear influence of mild hypothermia on the distribution of activated and non-activated forms of macrophages and monocytes in the inner ear was observed. Furthermore, these cells were located in the mesenchymal tissue in and around the cochlea, and the activated forms were found in and around the spiral ganglion tissue at 37 °C. Our findings suggest that mild hypothermic treatment has a beneficial effect on immune system activation after electrode insertion trauma.
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Affiliation(s)
| | | | | | | | - Joachim Schmutzhard
- Department of Otorhinolaryngology, Medical University Innsbruck, 6020 Innsbruck, Austria; (W.B.); (C.S.); (H.T.F.); (R.G.); (A.S.-F.)
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2
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Rahman MT, Chari DA, Ishiyama G, Lopez I, Quesnel AM, Ishiyama A, Nadol JB, Hansen MR. Cochlear implants: Causes, effects and mitigation strategies for the foreign body response and inflammation. Hear Res 2022; 422:108536. [PMID: 35709579 PMCID: PMC9684357 DOI: 10.1016/j.heares.2022.108536] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 04/20/2022] [Accepted: 05/23/2022] [Indexed: 12/15/2022]
Abstract
Cochlear implants provide effective auditory rehabilitation for patients with severe to profound sensorineural hearing loss. Recent advances in cochlear implant technology and surgical approaches have enabled a greater number of patients to benefit from this technology, including those with significant residual low frequency acoustic hearing. Nearly all cochleae implanted with a cochlear implant electrode array develop an inflammatory and fibrotic response. This tissue reaction can have deleterious consequences for implant function, residual acoustic hearing, and the development of the next generation of cochlear prosthetics. This article reviews the current understanding of the inflammatory/foreign body response (FBR) after cochlear implant surgery, its impact on clinical outcome, and therapeutic strategies to mitigate this response. Findings from both in human subjects and animal models across a variety of species are highlighted. Electrode array design, surgical techniques, implant materials, and the degree and type of electrical stimulation are some critical factors that affect the FBR and inflammation. Modification of these factors and various anti-inflammatory pharmacological interventions have been shown to mitigate the inflammatory/FBR response. Ongoing and future approaches that seek to limit surgical trauma and curb the FBR to the implanted biomaterials of the electrode array are discussed. A better understanding of the anatomical, cellular and molecular basis of the inflammatory/FBR response after cochlear implantation has the potential to improve the outcome of current cochlear implants and also facilitate the development of the next generation of neural prostheses.
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Affiliation(s)
- Muhammad T Rahman
- Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City, IA, USA
| | - Divya A Chari
- Department of Otolaryngology-Head & Neck Surgery, Harvard University, Boston, MA, USA
| | - Gail Ishiyama
- Department of Head & Neck Surgery, University of California Los Angeles, LA, USA
| | - Ivan Lopez
- Department of Head & Neck Surgery, University of California Los Angeles, LA, USA
| | - Alicia M Quesnel
- Department of Otolaryngology-Head & Neck Surgery, Harvard University, Boston, MA, USA
| | - Akira Ishiyama
- Department of Head & Neck Surgery, University of California Los Angeles, LA, USA
| | - Joseph B Nadol
- Department of Otolaryngology-Head & Neck Surgery, Harvard University, Boston, MA, USA
| | - Marlan R Hansen
- Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City, IA, USA.
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3
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Blebea CM, Ujvary LP, Necula V, Dindelegan MG, Perde-Schrepler M, Stamate MC, Cosgarea M, Maniu AA. Current Concepts and Future Trends in Increasing the Benefits of Cochlear Implantation: A Narrative Review. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:747. [PMID: 35744010 PMCID: PMC9229893 DOI: 10.3390/medicina58060747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/25/2022] [Accepted: 05/29/2022] [Indexed: 01/29/2023]
Abstract
Hearing loss is the most common neurosensory disorder, and with the constant increase in etiological factors, combined with early detection protocols, numbers will continue to rise. Cochlear implantation has become the gold standard for patients with severe hearing loss, and interest has shifted from implantation principles to the preservation of residual hearing following the procedure itself. As the audiological criteria for cochlear implant eligibility have expanded to include patients with good residual hearing, more attention is focused on complementary development of otoprotective agents, electrode design, and surgical approaches. The focus of this review is current aspects of preserving residual hearing through a summary of recent trends regarding surgical and pharmacological fundamentals. Subsequently, the assessment of new pharmacological options, novel bioactive molecules (neurotrophins, growth factors, etc.), nanoparticles, stem cells, and gene therapy are discussed.
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Affiliation(s)
- Cristina Maria Blebea
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
| | - Laszlo Peter Ujvary
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
| | - Violeta Necula
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
- County Clinical Emergency Hospital Cluj, 400347 Cluj Napoca, Romania
| | - Maximilian George Dindelegan
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
| | | | - Mirela Cristina Stamate
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
| | - Marcel Cosgarea
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
| | - Alma Aurelia Maniu
- Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400347 Cluj Napoca, Romania; (C.M.B.); (V.N.); (M.G.D.); (M.C.S.); (M.C.); (A.A.M.)
- County Clinical Emergency Hospital Cluj, 400347 Cluj Napoca, Romania
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4
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Pawley DC, Goncalves S, Bas E, Dikici E, Deo SK, Daunert S, Telischi F. Dexamethasone (DXM)‐Coated Poly(lactic‐
co
‐glycolic acid) (PLGA) Microneedles as an Improved Drug Delivery System for Intracochlear Biodegradable Devices. ADVANCED THERAPEUTICS 2021. [DOI: 10.1002/adtp.202100155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Devon C. Pawley
- Department of Biochemistry and Molecular Biology University of Miami Miller School of Medicine Miami FL 33136 USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami Miami FL 33136 USA
| | - Stefania Goncalves
- University of Miami Ear Institute Department of Otolaryngology University of Miami Miller School of Medicine Miami FL 33136 USA
| | - Esperanza Bas
- University of Miami Ear Institute Department of Otolaryngology University of Miami Miller School of Medicine Miami FL 33136 USA
| | - Emre Dikici
- Department of Biochemistry and Molecular Biology University of Miami Miller School of Medicine Miami FL 33136 USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami Miami FL 33136 USA
| | - Sapna K. Deo
- Department of Biochemistry and Molecular Biology University of Miami Miller School of Medicine Miami FL 33136 USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami Miami FL 33136 USA
| | - Sylvia Daunert
- Department of Biochemistry and Molecular Biology University of Miami Miller School of Medicine Miami FL 33136 USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute of the University of Miami Miami FL 33136 USA
- University of Miami Clinical and Translational Science Institute University of Miami Miller School of Medicine Miami FL 33136 USA
| | - Fred Telischi
- University of Miami Ear Institute Department of Otolaryngology University of Miami Miller School of Medicine Miami FL 33136 USA
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Davies C, Bergman J, Misztal C, Ramchandran R, Mittal J, Bulut E, Shah V, Mittal R, Eshraghi AA. The Outcomes of Cochlear Implantation in Usher Syndrome: A Systematic Review. J Clin Med 2021; 10:jcm10132915. [PMID: 34209904 PMCID: PMC8267700 DOI: 10.3390/jcm10132915] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/14/2022] Open
Abstract
Objective: To systematically appraise the implementation of cochlear implantation (CI) in Usher Syndrome (USH) Types 1, 2, and 3 patients, and analyze who would benefit from CI. Data Sources: A comprehensive search of PubMed, Embase, CINAHL, and Cochrane Library electronic databases from inception through June 2020 was performed. There were no language restrictions. Study Selection: The PRISMA strategy was followed. Included studies discuss USH patients who underwent CI regardless of age, nationality, or clinical subtype. All included studies report post-implantation functional, cognitive, or quality of life outcomes. Only reviews were excluded. Results: Fifteen studies met the inclusion criteria. USH patients experienced improvements in PTA and speech perception and expression outcomes after CI, as well as improvements in phonological memory and quality of life measures. Overall, patients implanted at younger ages outperformed older patients in audiological testing. Similarly, patients with prolonged auditory deprivation had relatively poor performance outcomes in sentence recognition and speech detection following CI. Conclusions: Most USH patients benefit from CI. USH patients who undergo CI at younger ages generally achieve better hearing, speech, and cognitive outcomes. CI at older ages can still prove beneficial if appropriate auditory amplification is started at the right time. Further research is warranted to fill the gap in understanding regarding the gene mutations underlying the pathophysiology of USH that have favorable CI outcomes as well as the optimal time to perform CI.
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Affiliation(s)
- Camron Davies
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Jenna Bergman
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Carly Misztal
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Renuka Ramchandran
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Jeenu Mittal
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Erdogan Bulut
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Viraj Shah
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Rahul Mittal
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
| | - Adrien A. Eshraghi
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (C.D.); (J.B.); (C.M.); (R.R.); (J.M.); (E.B.); (V.S.); (R.M.)
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA
- Department of Pediatrics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Correspondence:
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6
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Jaudoin C, Carré F, Gehrke M, Sogaldi A, Steinmetz V, Hue N, Cailleau C, Tourrel G, Nguyen Y, Ferrary E, Agnely F, Bochot A. Transtympanic injection of a liposomal gel loaded with N-acetyl-L-cysteine: A relevant strategy to prevent damage induced by cochlear implantation in guinea pigs? Int J Pharm 2021; 604:120757. [PMID: 34058306 DOI: 10.1016/j.ijpharm.2021.120757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 01/17/2023]
Abstract
Patients with residual hearing can benefit from cochlear implantation. However, insertion can damage cochlear structures and generate oxidative stress harmful to auditory cells. The antioxidant N-acetyl-L-cysteine (NAC) is a precursor of glutathione (GSH), a powerful endogenous antioxidant. NAC local delivery to the inner ear appeared promising to prevent damage after cochlear implantation in animals. NAC-loaded liposomal gel was specifically designed for transtympanic injection, performed both 3 days before and on the day of surgery. Hearing thresholds were recorded over 30 days in implanted guinea pigs with and without NAC. NAC, GSH, and their degradation products, N,N'-diacetyl-L-cystine (DiNAC) and oxidized glutathione (GSSG) were simultaneously quantified in the perilymph over 15 days in non-implanted guinea pigs. For the first time, endogenous concentrations of GSH and GSSG were determined in the perilymph. Although NAC-loaded liposomal gel sustained NAC release in the perilymph over 15 days, it induced hearing loss in both implanted and non-implanted groups with no perilymphatic GSH increase. Under physiological conditions, NAC appeared poorly stable within liposomes. As DiNAC was quantified at concentrations which were twice as high as NAC in the perilymph, it was hypothesized that DiNAC could be responsible for the adverse effects on hearing.
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Affiliation(s)
- Céline Jaudoin
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 5 rue J-B Clément, 92296 Châtenay-Malabry, France.
| | - Fabienne Carré
- Inserm/Institut Pasteur, Institut de l'audition, Technologies et thérapie génique pour la surdité, 63 rue de Charenton, 75012 Paris, France.
| | - Maria Gehrke
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 5 rue J-B Clément, 92296 Châtenay-Malabry, France.
| | - Audrey Sogaldi
- UMS IPSIT, SAMM, Faculté de Pharmacie, Université Paris-Saclay, 5 rue J-B Clément, 92296 Châtenay-Malabry, France.
| | - Vincent Steinmetz
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France.
| | - Nathalie Hue
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France.
| | - Catherine Cailleau
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 5 rue J-B Clément, 92296 Châtenay-Malabry, France.
| | - Guillaume Tourrel
- Oticon Medical/Neurelec SAS, Research & Technology Department, 2720 chemin Saint-Bernard, Vallauris, France.
| | - Yann Nguyen
- Inserm/Institut Pasteur, Institut de l'audition, Technologies et thérapie génique pour la surdité, 63 rue de Charenton, 75012 Paris, France; Sorbonne Université, AP-HP, GHU Pitié-Salpêtrière, DMU ChIR, Service ORL, GRC Robotique et Innovation Chirurgicale, 47-83, boulevard de l'hôpital, 75013 Paris, France.
| | - Evelyne Ferrary
- Inserm/Institut Pasteur, Institut de l'audition, Technologies et thérapie génique pour la surdité, 63 rue de Charenton, 75012 Paris, France.
| | - Florence Agnely
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 5 rue J-B Clément, 92296 Châtenay-Malabry, France.
| | - Amélie Bochot
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 5 rue J-B Clément, 92296 Châtenay-Malabry, France.
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7
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Abstract
Intra-cochlear fibrous tissue formation around the electrode following cochlear implantation affects the electrode impedance as well as electrode explantation during reimplantation surgeries. Applying corticosteroids in cochlear implantation is one way of minimizing the intra-cochlear fibrous tissue formation around the electrode. It were J. Kiefer, C. von Ilberg, and W. Gstöttner who proposed the first idea on drug delivery application in cochlear implantation to MED-EL in the year 2000. During the twenty years of translational research efforts at MED-EL in collaboration with several clinics and research institutions from across the world, preclinical safety and efficacy of corticosteroids were performed leading to the final formulation of the electrode design. In parallel to the drug eluting CI electrode development, MED-EL also invested research efforts into developing tools enabling delivery of pharmaceutical agents of surgeon's choice inside the cochlea. The inner ear catheter designed to administer drug substances into the cochlea was CE marked in 2020. A feasibility study in human subjects with MED-EL CI featuring dexamethasone-eluting electrode array started in June 2020. This article covers the milestones of translational research towards the drug delivery in CI application that took place in association with MED-EL.
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Affiliation(s)
| | - Ingeborg Hochmair
- MED-EL Elektromedizinische Geraete Gesellschaft m.b.H., Innsbruck, Austria
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Shah V, Mittal R, Shahal D, Sinha P, Bulut E, Mittal J, Eshraghi AA. Evaluating the Efficacy of Taurodeoxycholic Acid in Providing Otoprotection Using an in vitro Model of Electrode Insertion Trauma. Front Mol Neurosci 2020; 13:113. [PMID: 32760249 PMCID: PMC7372968 DOI: 10.3389/fnmol.2020.00113] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/02/2020] [Indexed: 12/13/2022] Open
Abstract
Cochlear implants (CIs) are widely used to provide auditory rehabilitation to individuals having severe to profound sensorineural hearing loss (SNHL). However, insertion of electrode leads to inner trauma and activation of inflammatory and apoptotic signaling cascades resulting in loss of residual hearing in implanted individuals. Pharmaceutical interventions that can target these signaling cascades hold great potential for preserving residual hearing by preventing sensory cell damage. Bile salts have shown efficacy in various regions of the body as powerful antioxidants and anti-inflammatory agents. However, their efficacy against inner ear trauma has never been explored. The objective of this study was to determine whether taurodeoxycholic acid (TDCA), a bile salt derivative, can prevent sensory cell damage employing an in vitro model of electrode insertion trauma (EIT). The organ of Corti (OC) explants were dissected from postnatal day 3 (P-3) rats and placed in serum-free media. Explants were divided into control and experimental groups: (1) untreated controls; (2) EIT; (3) EIT+ TDCA (different concentrations). Hair cell (HC) density, analyses of apoptosis pathway (cleaved caspase 3), levels of reactive oxygen species (ROS) as well as inducible nitric oxide synthase (iNOS) activity and Mitochondrial Membrane Potential (MMP) were assayed. Treatment with TDCA provided significant otoprotection against HC loss in a dose-dependent manner. The molecular mechanisms underlying otoprotection involved decreasing oxidative stress, lowering levels of iNOS, and abrogating generation of cleaved caspase 3. The results of the present study suggest that TDCA provides efficient otoprotection against EIT, in vitro and should be explored for developing pharmaceutical interventions to preserve residual hearing post-cochlear implantation.
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Affiliation(s)
- Viraj Shah
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Rahul Mittal
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - David Shahal
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Priyanka Sinha
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Erdogan Bulut
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Jeenu Mittal
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Adrien A Eshraghi
- Cochlear Implant and Hearing Research Laboratory, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States.,Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States.,Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
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9
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Evaluating the Efficacy of L-N-acetylcysteine and Dexamethasone in Combination to Provide Otoprotection for Electrode Insertion Trauma. J Clin Med 2020; 9:jcm9030716. [PMID: 32155788 PMCID: PMC7141216 DOI: 10.3390/jcm9030716] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 02/27/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Electrode insertion trauma (EIT) during cochlear implantation (CI) can cause loss of residual hearing. L-N-acetylcysteine (L-NAC) and dexamethasone (Dex) have been individually shown to provide otoprotection albeit at higher concentrations that may be associated with adverse effects. Objective/Aims: The aim of this study is to determine whether L-NAC and Dex could be combined to decrease their effective dosage. MATERIALS AND METHODS The organ of Corti (OC) explants were divided into various groups: 1) control; 2) EIT; 3) EIT treated with different concentrations of Dex; 4) EIT treated with different concentrations of L-NAC; 5) EIT treated with L-NAC and Dex in combination. Hair cell (HC) density, levels of oxidative stress, proinflammatory cytokines and nitric oxide (NO) was determined. RESULTS There was a significant loss of HCs in explants subjected to EIT compared to the control group. L-NAC and Dex in combination was able to provide significant otoprotection at lower concentrations compared to individual drugs. CONCLUSIONS AND SIGNIFICANCE A combination containing L-NAC and Dex is effective in protecting sensory cells at lower protective doses than each compound separately. These compounds can be combined allowing a decrease of potential side effects of each compound and providing significant otoprotection for EIT.
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10
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Tillinger JA, Gupta C, Ila K, Ahmed J, Mittal J, Van De Water TR, Eshraghi AA. l-N-acetylcysteine protects outer hair cells against TNFα initiated ototoxicity in vitro. Acta Otolaryngol 2018. [PMID: 29513056 DOI: 10.1080/00016489.2018.1440086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The present study is aimed at determining the efficacy and exploring the mechanisms by which l-N-acetylcysteine (l-NAC) provides protection against tumor necrosis factor-alpha (TNFα)-induced oxidative stress damage and hair cell loss in 3-day-old rat organ of Corti (OC) explants. Previous work has demonstrated a high level of oxidative stress in TNFα-challenged OC explants. TNFα can potentially play a significant role in hair cell loss following an insult to the inner ear. l-NAC has shown to provide effective protection against noise-induced hearing loss in laboratory animals but mechanisms of this otoprotective effect are not well-defined. DESIGN Rat OC explants were exposed to either: (1) saline control (N = 12); (2) TNFα (2 μg/ml, N = 12); (3) TNFα+l-NAC (5 mM, N = 12); (4) TNFα+l-NAC (10 mM, N = 12); or (5) l-NAC (10 mM, N = 12). Outer hair cell (OHC) density, levels of reactive oxygen species (ROS), lipid peroxidation of cell membranes, gluthathione activity, and mitochondrial viability were assayed. RESULTS l-NAC (5 and 10 mM) provided protection for OHCs from ototoxic level of TNFα in OC explants. Groups treated with TNFα+l-NAC (5 mM) showed a highly significant reduction of both ROS (p < 0.01) and 4-hydroxy-2-nonenal immunostaining (p < 0.001) compared to TNFα-challenged explants. Total glutathione levels were low in TNFα-challenged explants compared to control and TNFα+l-NAC (5 mM) treated explants (p < 0.001). CONCLUSIONS l-NAC is a promising treatment for protecting auditory HCs from TNFα-induced oxidative stress and subsequent loss via programmed cell death.
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Affiliation(s)
- Joshua A. Tillinger
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Chhavi Gupta
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Kadri Ila
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Jamal Ahmed
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Jeenu Mittal
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Thomas R. Van De Water
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Adrien A. Eshraghi
- Department of Otolaryngology, Hearing Research Laboratory, Miller School of Medicine University of Miami, Miami, FL, USA
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Eshraghi AA, Ocak E. Cochlear Implant Electrode Choice in Challenging Surgical Cases: Malformation, Residual Hearing, Ossification, or Reimplantation. CURRENT OTORHINOLARYNGOLOGY REPORTS 2017. [DOI: 10.1007/s40136-017-0171-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
Local drug application to the inner ear offers a number of advantages over systemic delivery. Local drug therapy currently encompasses extracochlear administration (i. e., through intratympanic injection), intracochlear administration (particularly for gene and stem cell therapy), as well as various combinations with auditory neurosensory prostheses, either evaluated in preclinical or clinical studies, or off-label. To improve rehabilitation with cochlear implants (CI), one focus is the development of drug-releasing electrode carriers, e. g., for delivery of glucocorticosteroids, antiapoptotic substances, or neurotrophins to the inner ear. The performance of cochlear implants may thus be improved by protecting neuronal structures from insertion trauma, reducing fibrosis in the inner ear, and by stimulating growth of neuronal structures in the direction of the electrodes. Controlled drug release after extracochlear or intracochlear application in conjunction with a CI can also be achieved by use of a biocompatible, resorbable controlled-release drug-delivery system. Two case reports for intracochlear controlled release drug delivery in combination with cochlear implants are presented. In order to treat progressive reduction in speech discrimination and increased impedance, two cochlear implant patients successfully underwent intracochlear placement of a biocompatible, resorbable drug-delivery system for controlled release of dexamethasone. The drug levels reached in inner ear fluids after different types of local drug application strategies can be calculated using a computer model. The intracochlear drug concentrations calculated in this way were compared for different dexamethasone application strategies.
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Perilymph pharmacokinetics of marker applied through a cochlear implant in guinea pigs. PLoS One 2017; 12:e0183374. [PMID: 28817653 PMCID: PMC5560723 DOI: 10.1371/journal.pone.0183374] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/02/2017] [Indexed: 11/26/2022] Open
Abstract
Patients undergoing cochlear implantation could benefit from a simultaneous application of drugs into the ear, helping preserve residual low-frequency hearing and afferent nerve fiber populations. One way to apply drugs is to incorporate a cannula into the implant, through which drug solution is driven. For such an approach, perilymph concentrations achieved and the distribution in the ear over time have not previously been documented. We used FITC-labeled dextran as a marker, delivering it into perilymph of guinea pigs at 10 or 100 nL/min though a cannula incorporated into a cochlear implant with the outlet in the mid basal turn. After injections of varying duration (2 hours, 1 day or 7 days) perilymph was collected from the cochlear apex using a sequential sampling technique, allowing dextran levels and gradients along scala tympani to be quantified. Data were interpreted quantitatively using computer simulations of the experiments. For injections of 2 hours duration, dextran levels were critically influenced by the presence or absence of fluid leakage at the cochleostomy site. When the cochleostomy was fluid-tight, substantially higher perilymph levels were achieved at the injection site, with concentration declining along scala tympani towards the apex. Contrary to expectations, large dextran gradients along scala tympani persisted after 24 hours of sustained injection and were still present in some animals after 7 days injection. Functional changes associated with implantation and dextran delivery, and the histological state of the implant and cannula were also documented. The persistent longitudinal gradients of dextan along the ear were not readily explained by computer simulations of the experiments based on prior pharmacokinetic data. One explanation is that inner ear pharmacokinetics are altered in the period after cochlear implantation, possibly by a permeabilization of the blood-labyrinth barrier as part of the immune response to the implant.
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Abstract
OBJECTIVE To critically review and evaluate the proposed mechanisms and documented results of the therapeutics currently in active clinical drug trials for the treatment of sensorineural hearing loss. DATA SOURCES US National Institutes of Health (NIH) Clinical Trials registry, MEDLINE/PubMed. STUDY SELECTION & DATA EXTRACTION A review of the NIH Clinical Trials registry identified candidate hearing loss therapies, and supporting publications were acquired from MEDLINE/PubMed. Proof-of-concept, therapeutic mechanisms, and clinical outcomes were critically appraised. DATA SYNTHESIS Twenty-two active clinical drug trials registered in the United States were identified, and six potentially therapeutic molecules were reviewed. Of the six molecules reviewed, four comprised mechanisms pertaining to mitigating oxidative stress pathways that presumably lead to inner ear cell death. One remaining therapy sought to manipulate the cell death cascade, and the last remaining therapy was a novel cell replacement therapy approach to introduce a transcription factor that promotes hair cell regeneration. CONCLUSION A common theme in recent clinical trials registered in the United States appears to be the targeting of cell death pathways and influence of oxidant stressors on cochlear sensory neuroepithelium. In addition, a virus-delivered cell replacement therapy would be the first of its kind should it prove safe and efficacious. Significant challenges for bringing these bench-to-bedside therapies to market remain. It is never assured that results in non-human animal models translate to effective therapies in the setting of human biology. Moreover, as additional processes are described in association with hearing loss, such as an immune response and loss of synaptic contacts, additional pathways for targeting become available.
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Affiliation(s)
- Matthew G. Crowson
- Division of Head & Neck Surgery & Communication Sciences, Department of Surgery, Duke University Medical Center, Durham, NC USA
| | - Ronna Hertzano
- Department of Otorhinolaryngology Head & Neck Surgery, Anatomy and Neurobiology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Debara Tucci
- Division of Head & Neck Surgery & Communication Sciences, Department of Surgery, Duke University Medical Center, Durham, NC USA
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Ruben RJ. The trajectory of Pediatric Otolaryngology. Int J Pediatr Otorhinolaryngol 2016; 89:179-82. [PMID: 27401025 DOI: 10.1016/j.ijporl.2016.06.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Robert J Ruben
- Albert Einstein College of Medicine, Montefiore Medical Center, United States.
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