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Cosentino A, Agafonova A, Modafferi S, Trovato Salinaro A, Scuto M, Maiolino L, Fritsch T, Calabrese EJ, Lupo G, Anfuso CD, Calabrese V. Blood-Labyrinth Barrier in Health and Diseases: Effect of Hormetic Nutrients. Antioxid Redox Signal 2024; 40:542-563. [PMID: 37565276 DOI: 10.1089/ars.2023.0251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Significance: The stria vascularis, located in the inner ear, consists of three layers, one of which is the blood-labyrinth barrier (BLB). It is formed by endothelial cells, sealed together to prevent the passage of toxic substances from the blood to the inner ear, by pericytes and perivascular-resident macrophage-like melanocyte. Recent Advances: There are various causes that lead to hearing loss, and among these are noise-induced and autoimmune hearing loss, ear disorders related to ototoxic medication, Ménière's disease, and age-related hearing loss. For all of these, major therapeutic interventions include drug-loaded nanoparticles, via intratympanic or intracochlear delivery. Critical Issues: Since many pathologies associated with hearing loss are characterized by a weakening of the BLB, in this review, the molecular mechanisms underlying the response to damage of BLB cellular components have been discussed. In addition, insight into the role of hormetic nutrients against hearing loss pathology is proposed. Future Directions: BLB cellular components of neurovascular cochlear unit play important physiological roles, owing to their impermeable function against all ototoxic substances that can induce damage. Studies are needed to investigate the cross talk occurring between these cellular components to exploit their possible role as novel targets for therapeutic interventions that may unravel future path based on the use of hormetic nutrients. Antioxid. Redox Signal. 40, 542-563.
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Affiliation(s)
- Alessia Cosentino
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Aleksandra Agafonova
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Sergio Modafferi
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Angela Trovato Salinaro
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Maria Scuto
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Luigi Maiolino
- Department of Medical, Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | | | - Edward J Calabrese
- Department of Environmental Health, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Gabriella Lupo
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Carmelina Daniela Anfuso
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
| | - Vittorio Calabrese
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, School of Medicine; Surgical and Advanced Technologies "G. F. Ingrassia"; University of Catania, Catania, Italy
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2
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Feng SJ, Leong S, Aksit A, Hébert D, Olson ES, Kysar JW, Lalwani AK. Physiologic Effects of Microneedle-Mediated Intracochlear Dexamethasone Injection in the Guinea Pig. Laryngoscope 2024; 134:388-392. [PMID: 37318112 DOI: 10.1002/lary.30811] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/01/2023] [Accepted: 05/29/2023] [Indexed: 06/16/2023]
Abstract
OBJECTIVES Oral or intratympanic corticosteroids are commonly used to treat sudden sensorineural hearing loss (SSHL), tinnitus, and Meniere disease. Direct intracochlear delivery has been proposed to overcome the variability in bioavailability and efficacy of systemic or middle ear delivery. In this study, we aim to characterize the physiologic consequences of microneedle-mediated direct intracochlear injection of dexamethasone through the round window membrane (RWM). METHODS In Hartley guinea pigs (n = 5), a post-auricular incision followed by bullostomy was made to access the round window membrane. Using 100 μm diameter hollow microneedles, 1.0 μl of 10 mg/ml dexamethasone was injected through the RWM over 1 min. Compound action potential (CAP) and distortion product otoacoustic action emissions (DPOAE) were measured before perforation, at 1 h, and at 5 h following injection. CAP hearing thresholds were measured from 0.5 to 40 kHz, and DPOAE f2 frequencies ranged from 1.0 and 32 kHz. Repeated measures ANOVA followed by pairwise t-tests were used for statistical analysis. RESULTS ANOVA identified significant CAP threshold shifts at four frequencies (4, 16, 36, and 40 kHz) and differences in DPOAE at 1 frequency (6 kHz). Paired t-tests revealed differences between the pre-perforation and 1 h time point. By 5 h post injection, both CAP hearing thresholds and DPOAE recover and are not significantly different from baseline thresholds. CONCLUSION Direct intracochlear delivery of dexamethasone via microneedles results in temporary shifts in hearing thresholds that resolve by 5 hours, thus supporting microneedle technology for the treatment of inner ear disorders. LEVEL OF EVIDENCE NA Laryngoscope, 134:388-392, 2024.
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Affiliation(s)
- Sharon J Feng
- Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, U.S.A
- Department of Otolaryngology-Head and Neck Surgery, NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, U.S.A
| | - Stephen Leong
- Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, U.S.A
- Department of Otolaryngology-Head and Neck Surgery, NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, U.S.A
| | - Aykut Aksit
- Department of Mechanical Engineering, Columbia University, New York, New York, U.S.A
| | - Daniella Hébert
- Department of Mechanical Engineering, Columbia University, New York, New York, U.S.A
| | - Elizabeth S Olson
- Department of Otolaryngology-Head and Neck Surgery, NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, U.S.A
- Department of Biomedical Engineering, Columbia University, New York, New York, U.S.A
| | - Jeffrey W Kysar
- Department of Mechanical Engineering, Columbia University, New York, New York, U.S.A
| | - Anil K Lalwani
- Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, U.S.A
- Department of Otolaryngology-Head and Neck Surgery, NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, U.S.A
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3
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Yang S, Wu Y, Cheng X, Zhang LW, Yu Y, Wang Y, Wang Y. Harnessing astaxanthin-loaded diselenium cross-linked apotransferrin nanoparticles for the treatment of secretory otitis media. J Control Release 2024; 365:398-411. [PMID: 38007194 DOI: 10.1016/j.jconrel.2023.11.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/09/2023] [Accepted: 11/20/2023] [Indexed: 11/27/2023]
Abstract
Secretory otitis media (SOM) is a clinical condition characterized by the accumulation of fluids and oxidative stress in the middle ear, leading to hearing impairment and infection complications. One potential solution for mitigating oxidative stress associated with SOM is the use of antioxidants such as astaxanthin. However, its effectiveness is limited due to its poor bioavailability and rapid oxidation. Herein, we developed a novel diselenium-crosslinked apotransferrin enriched with astaxanthin (AST@dSe-AFT) nanoparticles to augment the transport of astaxanthin across biological membranes, resulting in increased bioavailability and reduced oxidative stress in SOM. Our research demonstrated that AST@dSe-AFT efficiently accumulated in the middle ear, allowing for controlled delivery of astaxanthin in response to reactive oxygen species and reducing oxidative stress. Additionally, AST@dSe-AFT stimulated macrophages to polarize towards M2 phenotype and neutrophils to polarize towards N2 phenotype, thereby facilitating an anti-inflammatory response and tissue restoration. Importantly, AST@dSe-AFT exhibited no toxicity or adverse effects, suggesting its potential for safety and future clinical translation. Our findings suggested that AST@dSe-AFT represents a promising approach for the treatment of secretory otitis media and other oxidative stress-related disorders.
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Affiliation(s)
- Siqi Yang
- Department of Otolaryngology, The First Affiliated Hospital of Soochow University, 899 Pinghai Road, Suzhou 215006, China
| | - Yanxian Wu
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China
| | - Xiaju Cheng
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China
| | - Leshuai W Zhang
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China
| | - Yafeng Yu
- Department of Otolaryngology, The First Affiliated Hospital of Soochow University, 899 Pinghai Road, Suzhou 215006, China.
| | - Yong Wang
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China.
| | - Yangyun Wang
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China.
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Lehner E, Honeder C, Knolle W, Binder W, Scheffler J, Plontke SK, Liebau A, Mäder K. Towards the optimization of drug delivery to the cochlear apex: Influence of polymer and drug selection in biodegradable intracochlear implants. Int J Pharm 2023; 643:123268. [PMID: 37488058 DOI: 10.1016/j.ijpharm.2023.123268] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/26/2023]
Abstract
There is growing need for new drug delivery systems for intracochlear application of drugs to effectively treat inner ear disorders. In this study, we describe the development and characterization of biodegradable, triamcinolone-loaded implants based on poly(lactic-co-glycolic acid) (PLGA) and polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) respectively, prepared by hot-melt extrusion. PEG 1500 was used as a plasticizer to improve flexibility and accelerate drug release. The sterilization process was performed by electron beam irradiation, resulting in minimal but acceptable polymer degradation for PEG-PLGA implants. The implants have been characterized by texture analysis, differential scanning calorimetry and X-ray powder diffraction. Compared to PLGA implants, PEG-PLGA implants offer similar flexibility but with improved mechanical stability, which will ease the handling and intracochlear application. A controlled release over three months was observed for dexamethasone and triamcinolone extrudates (drug load of 10%) with similar release profiles for both drugs. PEG-PLGA implants showed an initial slow release rate over several days regardless of the amount of PEG added. Mathematical simulations of the pharmacokinetics of the inner ear based on the in vitro release kinetics indicate a complete distribution of triamcinolone in the whole human scala tympani, which underlines the high potential of the developed formulation.
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Affiliation(s)
- E Lehner
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany.
| | - C Honeder
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - W Knolle
- Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany
| | - W Binder
- Institute of Chemistry, Martin-Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - J Scheffler
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - S K Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany; Halle Research Centre for Drug Therapy (HRCDT), Halle (Saale), Germany
| | - A Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - K Mäder
- Institute of Pharmacy, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany; Halle Research Centre for Drug Therapy (HRCDT), Halle (Saale), Germany
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5
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Lehner E, Menzel M, Gündel D, Plontke SK, Mäder K, Klehm J, Kielstein H, Liebau A. Microimaging of a novel intracochlear drug delivery device in combination with cochlear implants in the human inner ear. Drug Deliv Transl Res 2022; 12:257-266. [PMID: 33543398 PMCID: PMC8677643 DOI: 10.1007/s13346-021-00914-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2021] [Indexed: 12/17/2022]
Abstract
The effective delivery of drugs to the inner ear is still an unmet medical need. Local controlled drug delivery to this sensory organ is challenging due to its location in the petrous bone, small volume, tight barriers, and high vulnerability. Local intracochlear delivery of drugs would overcome the limitations of intratympanic (extracochlear) and systemic drug application. The requirements for such a delivery system include small size, appropriate flexibility, and biodegradability. We have developed biodegradable PLGA-based implants for controlled intracochlear drug release that can also be used in combination with cochlear implants (CIs), which are implantable neurosensory prosthesis for hearing rehabilitation. The drug carrier system was tested for implantation in the human inner ear in 11 human temporal bones. In five of the temporal bones, CI arrays from different manufacturers were implanted before insertion of the biodegradable PLGA implants. The drug carrier system and CI arrays were implanted into the scala tympani through the round window. Implanted temporal bones were evaluated by ultra-high-resolution computed tomography (µ-CT) to illustrate the position of implanted electrode carriers and the drug carrier system. The µ-CT measurements revealed the feasibility of implanting the PLGA implants into the scala tympani of the human inner ear and co-administration of the biodegradable PLGA implant with a CI array.
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Affiliation(s)
- Eric Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Matthias Menzel
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany
| | - Daniel Gündel
- Department of Nuclear Medicine, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Stefan K Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Karsten Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Jessica Klehm
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany
| | - Heike Kielstein
- Institute of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Arne Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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6
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Qnouch A, Solarczyk V, Verin J, Tourrel G, Stahl P, Danede F, Willart JF, Lemesre PE, Vincent C, Siepmann J, Siepmann F. Dexamethasone-loaded cochlear implants: How to provide a desired "burst release". INTERNATIONAL JOURNAL OF PHARMACEUTICS-X 2021; 3:100088. [PMID: 34553137 PMCID: PMC8441626 DOI: 10.1016/j.ijpx.2021.100088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 06/03/2021] [Accepted: 06/06/2021] [Indexed: 12/20/2022]
Abstract
Cochlear implants containing iridium platinum electrodes are used to transmit electrical signals into the inner ear of patients suffering from severe or profound deafness without valuable benefit from conventional hearing aids. However, their placement is invasive and can cause trauma as well as local inflammation, harming remaining hair cells or other inner ear cells. As foreign bodies, the implants also induce fibrosis, resulting in a less efficient conduction of the electrical signals and, thus, potentially decreased system performance. To overcome these obstacles, dexamethasone has recently been embedded in this type of implants: into the silicone matrices separating the metal electrodes (to avoid short circuits). It has been shown that the resulting drug release can be controlled over several years. Importantly, the dexamethasone does not only act against the immediate consequences of trauma, inflammation and fibrosis, it can also be expected to be beneficial for remaining hair cells in the long term. However, the reported amounts of drug released at “early” time points (during the first days/weeks) are relatively low and the in vivo efficacy in animal models was reported to be non-optimal. The aim of this study was to increase the initial “burst release” from the implants, adding a freely water-soluble salt of a phosphate ester of dexamethasone. The idea was to facilitate water penetration into the highly hydrophobic system and, thus, to promote drug dissolution and diffusion. This approach was efficient: Adding up to 10% dexamethasone sodium phosphate to the silicone matrices substantially increased the resulting drug release rate at early time points. This can be expected to improve drug action and implant functionality. But at elevated dexamethasone sodium phosphate loadings device swelling became important. Since the cochlea is a tiny and sensitive organ, a potential increase in implant dimensions over time must be limited. Hence, a balance has to be found between drug release and implant swelling.
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Affiliation(s)
- A Qnouch
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - V Solarczyk
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Verin
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - G Tourrel
- Oticon Medical, R&D, 06224 Vallauris, France
| | - P Stahl
- Oticon Medical, R&D, 06224 Vallauris, France
| | - F Danede
- Univ. Lille, UMR CNRS 8207, UMET, F-59655 Villeneuve d'Ascq, France
| | - J F Willart
- Univ. Lille, UMR CNRS 8207, UMET, F-59655 Villeneuve d'Ascq, France
| | - P E Lemesre
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - C Vincent
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - F Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
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7
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Lehner E, Liebau A, Syrowatka F, Knolle W, Plontke SK, Mäder K. Novel biodegradable Round Window Disks for inner ear delivery of dexamethasone. Int J Pharm 2020; 594:120180. [PMID: 33338566 DOI: 10.1016/j.ijpharm.2020.120180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/20/2022]
Abstract
Drug delivery to the inner ear is an important and very challenging field. The cochlea is protected by several barriers that need to be overcome in the drug delivery process. Local drug delivery can avoid undesirable side effects arising from systemic drug delivery. We developed a biodegradable dexamethasone-loaded Round Window (RW) Disk based on poly(D,L-lactic-co-glycolic acid) (PLGA) for local drug therapy to the inner ear by RW membrane administration by a film-casting method. The optimal drying time was characterized by thermogravimetric analysis and differential scanning calorimetry. In addition, the mass and polymer degradation over time of drug release was measured in vitro showing a total mass loss of 70% after 3 weeks. Dexamethasone release was determined by a RW model setup using a polyethylene terephthalate membrane. We achieved a controlled release over 52 days. Ex vivo implantation of a RW Disk onto a guinea pig RW membrane indicated well-fitting properties of the drug delivery device leading to a close surface contact with the membrane and the successful proof of concept. The developed RW Disks could be new and promising drug delivery device to achieve effective local drug delivery to the inner ear for an extended time.
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Affiliation(s)
- E Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - A Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - F Syrowatka
- Interdisciplinary Center of Materials Science, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - W Knolle
- Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany
| | - S K Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - K Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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8
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Silk-coated dexamethasone non-spherical microcrystals for local drug delivery to inner ear. Eur J Pharm Sci 2020; 150:105336. [DOI: 10.1016/j.ejps.2020.105336] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/26/2020] [Accepted: 03/30/2020] [Indexed: 11/21/2022]
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9
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State-of-the-art methods in clinical intracochlear drug delivery. Curr Opin Otolaryngol Head Neck Surg 2020; 27:381-386. [PMID: 31460985 DOI: 10.1097/moo.0000000000000566] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Increasing awareness and prevalence of disorders in hearing and balance have placed emphasis on treatment strategies. With the rapid evolution in molecular, gene, and nanotechnology, alternate delivery methods have advanced intracochlear drug delivery. This review aims to raise awareness of recent developments in technologies to augment current clinical practices. RECENT FINDINGS Intracochlear drug delivery research has expanded with the familiarity and accessibility to cochlear implantation. Various therapeutics are closely studied for both safety and efficacy as well as biologic effect. Agents including neurotrophins, antiapoptotics, cell therapy, gene therapy, and anti-inflammatory drugs are on the forefront of preclinical research. Cochlear implant electrode modification and drug administration at the time of implantation is a major focus of research. Improvements in study design have focused on overcoming barriers including elucidating the role of the blood-perilymph barrier. SUMMARY Inner ear drug delivery methods include systemic, intratympanic, and intracochlear administration. Therapeutic technologies aim to overcome delivery barriers and to improve overall biologic effect while minimizing toxicity. Precision of drug application through intratympanic and intracochlear administration with minimal trauma is the future of inner ear drug development.
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Szeto B, Chiang H, Valentini C, Yu M, Kysar JW, Lalwani AK. Inner ear delivery: Challenges and opportunities. Laryngoscope Investig Otolaryngol 2020; 5:122-131. [PMID: 32128438 PMCID: PMC7042639 DOI: 10.1002/lio2.336] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/21/2019] [Accepted: 11/21/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES The treatment of inner ear disorders remains challenging due to anatomic barriers intrinsic to the bony labyrinth. The purpose of this review is to highlight recent advances and strategies for overcoming these barriers and to discuss promising future avenues for investigation. DATA SOURCES The databases used were PubMed, EMBASE, and Web of Science. RESULTS Although some studies aimed to improve systemic delivery using nanoparticle systems, the majority enhanced local delivery using hydrogels, nanoparticles, and microneedles. Developments in direct intracochlear delivery include intracochlear injection and intracochlear implants. CONCLUSIONS In the absence of a systemic drug that targets only the inner ear, the best alternative is local delivery that harnesses a combination of new strategies to overcome anatomic barriers. The combination of microneedle technology with hydrogel and nanoparticle delivery is a promising area for future investigation. LEVEL OF EVIDENCE NA.
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Affiliation(s)
- Betsy Szeto
- Department of Otolaryngology–Head and Neck SurgeryColumbia University Vagelos College of Physicians and SurgeonsNew YorkNew York
| | - Harry Chiang
- Department of Otolaryngology–Head and Neck SurgeryColumbia University Vagelos College of Physicians and SurgeonsNew YorkNew York
| | - Chris Valentini
- Department of Otolaryngology–Head and Neck SurgeryColumbia University Vagelos College of Physicians and SurgeonsNew YorkNew York
| | - Michelle Yu
- Department of Otolaryngology–Head and Neck SurgeryColumbia University Vagelos College of Physicians and SurgeonsNew YorkNew York
| | - Jeffrey W. Kysar
- Department of Otolaryngology–Head and Neck SurgeryColumbia University Vagelos College of Physicians and SurgeonsNew YorkNew York
- Department of Mechanical Engineering, School of EngineeringColumbia UniversityNew YorkNew York
| | - Anil K. Lalwani
- Department of Otolaryngology–Head and Neck SurgeryColumbia University Vagelos College of Physicians and SurgeonsNew YorkNew York
- Department of Mechanical Engineering, School of EngineeringColumbia UniversityNew YorkNew York
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11
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Lehner E, Gündel D, Liebau A, Plontke S, Mäder K. Intracochlear PLGA based implants for dexamethasone release: Challenges and solutions. Int J Pharm X 2019; 1:100015. [PMID: 31517280 PMCID: PMC6733303 DOI: 10.1016/j.ijpx.2019.100015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 11/19/2022] Open
Abstract
The effective treatment of diseases of the inner ear is currently an unmet medical need. Local controlled drug delivery to the cochlea is challenging due to the hidden location, small volume and high sensitivity of this organ. A local intracochlear delivery of drugs would avoid the problems of intratympanic (extracochlear) drug application, but is more invasive. The requirements for such a delivery system include a small size and appropriate flexibility. The delivery device must be rigid enough for surgical handling but also flexible to avoid traumatizing cochlear structures. We developed biodegradable dexamethasone loaded PLGA extrudates for the controlled intracochlear release. In order to achieve the desired flexibility, Polyethylene glycol (PEG) was used as a plasticizer. In addition to the drug release, the extrudates were characterized in vitro by differential scanning calorimetry (DSC) and texture analysis. Simulation of the pharmacokinetics of the inner ear support the expectation that a constant perilymph drug level is obtained after few hours and retained over several weeks. Ex vivo implantation of the extrudates into a guinea pig cochlea indicate that PEG containing extrudates have the desired balance between mechanical strength and flexibility for direct implantation into the cochlea. The location of the implant was visualized by computer tomography. In summary, we postulate that intracochlear administration of drug releasing biodegradable implants is a new and promising approach to achieve local drug delivery to the cochlea for an extended time.
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Affiliation(s)
- E. Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - D. Gündel
- Department of Nuclear Medicine, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - A. Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - S. Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - K. Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
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