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Lee MY, Jung SK, Jang J, Choi H, Choung YH, Jang JH. Sialyllactose preserves residual hearing after cochlear implantation. Sci Rep 2024; 14:13376. [PMID: 38862572 PMCID: PMC11167013 DOI: 10.1038/s41598-024-62344-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 05/15/2024] [Indexed: 06/13/2024] Open
Abstract
In individuals with hearing loss, protection of residual hearing is essential following cochlear implantation to facilitate acoustic and electric hearing. Hearing preservation requires slow insertion, atraumatic electrode and delivery of the optimal quantity of a pharmacological agent. Several studies have reported variable hearing outcomes with osmotic pump-mediated steroid delivery. New drugs, such as sialyllactose (SL) which have anti-inflammatory effect in many body parts, can prevent tissue overgrowth. In the present study, the positive effects of the pharmacological agent SL against insults were evaluated in vitro using HEI-OC1 cells. An animal model to simulate the damage due to electrode insertion during cochlear implantation was used. SL was delivered using osmotic pumps to prevent loss of the residual hearing in this animal model. Hearing deterioration, tissue fibrosis and ossification were confirmed in this animal model. Increased gene expressions of inflammatory cytokines were identified in the cochleae following dummy electrode insertion. Following the administration of SL, insertion led to a decrease in hearing threshold shifts, tissue reactions, and inflammatory markers. These results emphasize the possible role of SL in hearing preservation and improve our understanding of the mechanism underlying hearing loss after cochlear implantation.
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Affiliation(s)
- Min Young Lee
- Department of Otolaryngology, Dankook University Hospital, Cheonan, Republic of Korea
| | - Seo-Kyung Jung
- Department of Otorhinolaryngology, Ajou University School of Medicine, San 5, Wonchon-dong, Yeongtong-gu, Suwon, 443-721, Republic of Korea
| | - Jongmoon Jang
- Department of Functional Ceramics, Korea Institute of Materials Science (KIMS), Changwon, Republic of Korea
| | - Hongsoo Choi
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Yun-Hoon Choung
- Department of Otorhinolaryngology, Ajou University School of Medicine, San 5, Wonchon-dong, Yeongtong-gu, Suwon, 443-721, Republic of Korea
| | - Jeong Hun Jang
- Department of Otorhinolaryngology, Ajou University School of Medicine, San 5, Wonchon-dong, Yeongtong-gu, Suwon, 443-721, Republic of Korea.
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Hu Y, Fang L, Zhang H, Zheng S, Liao M, Cui Q, Wei H, Wu D, Cheng H, Qi Y, Wang H, Xin T, Wang T, Chai R. Emerging biotechnologies and biomedical engineering technologies for hearing reconstruction. SMART MEDICINE 2023; 2:e20230021. [PMID: 39188297 PMCID: PMC11235852 DOI: 10.1002/smmd.20230021] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/09/2023] [Indexed: 08/28/2024]
Abstract
Hearing impairment is a global health problem that affects social communications and the economy. The damage and loss of cochlear hair cells and spiral ganglion neurons (SGNs) as well as the degeneration of neurites of SGNs are the core causes of sensorineural hearing loss. Biotechnologies and biomedical engineering technologies provide new hope for the treatment of auditory diseases, which utilizes biological strategies or tissue engineering methods to achieve drug delivery and the regeneration of cells, tissues, and even organs. Here, the advancements in the applications of biotechnologies (including gene therapy and cochlear organoids) and biomedical engineering technologies (including drug delivery, electrode coating, electrical stimulation and bionic scaffolds) in the field of hearing reconstruction are presented. Moreover, we summarize the challenges and provide a perspective on this field.
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Affiliation(s)
- Yangnan Hu
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
- Co‐Innovation Center of NeuroregenerationNantong UniversityNantongChina
| | - Le Fang
- Department of NeurologyThe China‐Japan Union Hospital of Jilin UniversityChangchunJilinChina
| | - Hui Zhang
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Shasha Zheng
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Menghui Liao
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Qingyue Cui
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Hao Wei
- Department of Otolaryngology Head and Neck SurgeryAffiliated Drum Tower Hospital of Nanjing University Medical SchoolJiangsu Provincial Key Medical DisciplineNanjingChina
| | - Danqi Wu
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Hong Cheng
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Yanru Qi
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Huan Wang
- The Eighth Affiliated HospitalSun Yat‐Sen UniversityShenzhenChina
| | - Tao Xin
- Department of NeurosurgeryThe First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan HospitalJinanChina
- Medical Science and Technology Innovation CenterShandong First Medical University and Shandong Academy of Medical SciencesJinanChina
| | - Tian Wang
- Department of Otolaryngology‐Head and Neck SurgeryStanford University School of MedicineStanfordCaliforniaUSA
- Department of Otolaryngology‐Head and Neck SurgeryThe Second Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina
| | - Renjie Chai
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
- Co‐Innovation Center of NeuroregenerationNantong UniversityNantongChina
- Department of Otolaryngology Head and Neck SurgerySichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengduChina
- Institute for Stem Cell and RegenerationChinese Academy of SciencesBeijingChina
- Beijing Key Laboratory of Neural Regeneration and RepairCapital Medical UniversityBeijingChina
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Isaakidou A, Apachitei I, Fratila-Apachitei LE, Zadpoor AA. High-Precision 3D Printing of Microporous Cochlear Implants for Personalized Local Drug Delivery. J Funct Biomater 2023; 14:494. [PMID: 37888159 PMCID: PMC10607433 DOI: 10.3390/jfb14100494] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/28/2023] [Accepted: 09/30/2023] [Indexed: 10/28/2023] Open
Abstract
Hearing loss is a highly prevalent multifactorial disorder affecting 20% of the global population. Current treatments using the systemic administration of drugs are therapeutically ineffective due to the anatomy of the cochlea and the existing blood-labyrinth barrier. Local drug delivery systems can ensure therapeutic drug concentrations locally while preventing adverse effects caused by high dosages of systemically administered drugs. Here, we aimed to design, fabricate, and characterize a local drug delivery system for the human cochlea. The design was relevant to the size of the human ear, included two different shapes, and incorporated two different microporous structures acting as reservoirs for drug loading and release. The four cochlear implant designs were printed using the two-photon polymerization (2PP) technique and the IP-Q photoresist. The optimized 2PP process enabled the fabrication of the cochlear implants with great reproducibility and shape fidelity. Rectangular and cylindrical implants featuring cylindrical and tapered tips, respectively, were successfully printed. Their outer dimensions were 0.6 × 0.6 × 2.4 mm3 (L × W × H). They incorporated internal porous networks that were printed with high accuracy, yielding pore sizes of 17.88 ± 0.95 μm and 58.15 ± 1.62 μm for the designed values of 20 μm and 60 μm, respectively. The average surface roughness was 1.67 ± 0.24 μm, and the water contact angle was 72.3 ± 3.0°. A high degree of polymerization (~90%) of the IP-Q was identified after printing, and the printed material was cytocompatible with murine macrophages. The cochlear implants designed and 3D printed in this study, featuring relevant sizes for the human ear and tunable internal microporosity, represent a novel approach for personalized treatment of hearing loss through local drug delivery.
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Affiliation(s)
- Aikaterini Isaakidou
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands; (I.A.); (A.A.Z.)
| | | | - Lidy Elena Fratila-Apachitei
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands; (I.A.); (A.A.Z.)
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Abstract
PURPOSE OF REVIEW Treatment of auditory dysfunction is dependent on inner ear drug delivery, with microtechnologies playing an increasingly important role in cochlear access and pharmacokinetic profile control. This review examines recent developments in the field for clinical and animal research environments. RECENT FINDINGS Micropump technologies are being developed for dynamic control of flow rates with refillable reservoirs enabling timed delivery of multiple agents for protection or regeneration therapies. These micropumps can be combined with cochlear implants with integral catheters or used independently with cochleostomy or round window membrane (RWM) delivery modalities for therapy development in animal models. Sustained release of steroids with coated cochlear implants remains an active research area with first-time-in-human demonstration of reduced electrode impedances. Advanced coatings containing neurotrophin producing cells have enhanced spiral ganglion neuron survival in animal models, and have proven safe in a human study. Microneedles have emerged for controlled microperforation of the RWM for significant enhancement in permeability, combinable with emerging matrix formulations that optimize biological interaction and drug release kinetics. SUMMARY Microsystem technologies are providing enhanced and more controlled access to the inner ear for advanced drug delivery approaches, alone and in conjunction with cochlear implants.
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Lee MY, Kim YC, Jang J, Jung JY, Choi H, Jang JH, Choung YH. Dexamethasone delivery for hearing preservation in animal cochlear implant model: continuity, long-term release, and fast release rate. Acta Otolaryngol 2020; 140:713-722. [PMID: 32449405 DOI: 10.1080/00016489.2020.1763457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Background: Clinically, steroids have been used for hearing preservation both topically and systemically during cochlear implantation.Objective: This study compared steroid efficacy for hearing preservation among different types of delivery modes using an animal experiment.Materials and methods: For 76 guinea pigs, topical and systemic delivery methods, four pump types with different infusion rates, delivery durations, and total steroid amounts were used. Threshold changes of 8, 16, and 32 kHz after dummy electrode insertion were evaluated at 1 and 4 weeks and compared among delivery method and pump types. Inflammatory response in the cochlea was histologically compared.Results: For topical delivery groups, long-term release showed advantages in preserving hearing. Systemic delivery groups showed smaller threshold shifts than control group in all frequencies (p > .05). In short-term low dose application, compared to topical delivery, systemic delivery showed advantage in hearing preservation at both time point. However, others fail to show significant difference between two methods. Histologically, inflammatory response in the scala tympani at the basal turn was less in systemic delivery, especially in high dose and long-term.Conclusion and significance: The difference of hearing preservation was not obvious between two delivery methods. Higher dose and longer duration might have advantages in hearing preservation.
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Affiliation(s)
- Min Young Lee
- Department of Otolaryngology, Dankook University School of Medicine, Cheonan, South Korea
| | - Young Cheol Kim
- Department of Otorhinolaryngology, Ajou University School of Medicine, Suwon, South Korea
| | - Jongmoon Jang
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Jae Yun Jung
- Department of Otolaryngology, Dankook University School of Medicine, Cheonan, South Korea
| | - Hongsoo Choi
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Jeong Hun Jang
- Department of Otorhinolaryngology, Ajou University School of Medicine, Suwon, South Korea
| | - Yun-Hoon Choung
- Department of Otorhinolaryngology, Ajou University School of Medicine, Suwon, South Korea
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Ahmadi N, Gausterer JC, Honeder C, Mötz M, Schöpper H, Zhu C, Saidov N, Gabor F, Arnoldner C. Long-term effects and potential limits of intratympanic dexamethasone-loaded hydrogels combined with dexamethasone-eluting cochlear electrodes in a low-insertion trauma Guinea pig model. Hear Res 2019; 384:107825. [PMID: 31669876 DOI: 10.1016/j.heares.2019.107825] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/07/2019] [Accepted: 10/16/2019] [Indexed: 12/11/2022]
Abstract
Cochlear implantation has become the most effective hearing restoration method and is one of the great advances in modern medicine. Early implants have been continuously developed into more efficient devices, and electro-acoustic stimulation is increasingly expanding the indication criteria for cochlear implants to patients with more residual hearing. Therefore, protecting the cochlear structures and maintaining its intrinsic capacities like residual hearing has become more important than ever before. In the present study, we aimed to assess the long-term protective effects of a dexamethasone-eluting electrode combined with the preoperative intratympanic application of a dexamethasone-loaded thermoreversible hydrogel in a cochlear implant guinea pig model. 40 normal-hearing animals were equally randomized into a control group receiving an unloaded hydrogel and a non-eluting electrode, a group receiving a dexamethasone-loaded hydrogel and a non-eluting electrode, a group receiving an unloaded hydrogel and a dexamethasone-eluting electrode and a group receiving both a dexamethasone-loaded hydrogel and a dexamethasone-eluting electrode. Residual hearing and impedances were investigated during a period of 120 days. Tissue response and histological changes of cochlear structures were analyzed at the end of the experiments. Treatment with dexamethasone did not show a significant protective effect on residual hearing independent of treatment group. Although the majority of the cochleae didn't exhibit any signs of electrode insertion trauma, a small degree of tissue response could be observed in all animals without a significant difference between the groups. Foreign body giant cells and osteogenesis were significantly associated with tissue response. Hair cells, synapsin-1-positive cells and spiral ganglion cells were preserved in all study groups. Cochlear implantation using a dexamethasone-eluting electrode alone and in combination with a dexamethasone-loaded hydrogel significantly protected auditory nerve fibers on day 120. Post-implantation impedances were equal across study groups and remained stable over the duration of the experiment. In this study we were able to show that use of a dexamethasone-eluting electrode alone and in combination with preoperative application of dexamethasone-loaded hydrogel significantly protects auditory nerve fibers. Furthermore, we have shown that a cochlear implantation-associated hearing threshold shift and tissue response may not be completely prevented by the sole application of dexamethasone.
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Affiliation(s)
- Navid Ahmadi
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
| | - Julia Clara Gausterer
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria.
| | - Clemens Honeder
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
| | - Marlene Mötz
- Department of Pathobiology, Institute of Anatomy, Histology and Embryology, University of Veterinary Medicine Vienna, Austria.
| | - Hanna Schöpper
- Department of Pathobiology, Institute of Anatomy, Histology and Embryology, University of Veterinary Medicine Vienna, Austria.
| | - Chengjing Zhu
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
| | - Nodir Saidov
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
| | - Franz Gabor
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria.
| | - Christoph Arnoldner
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
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Jang J, Kim J, Kim YC, Kim S, Chou N, Lee S, Choung Y, Kim S, Brugger J, Choi H, Jang JH. A 3D Microscaffold Cochlear Electrode Array for Steroid Elution. Adv Healthc Mater 2019; 8:e1900379. [PMID: 31532887 DOI: 10.1002/adhm.201900379] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 09/04/2019] [Indexed: 11/05/2022]
Abstract
In cochlear implants, the electrode insertion trauma during surgery can cause damage residual hearing. Preserving the residual hearing is an important challenge and the localized administration of drugs, such as steroids, is one of the most promising ways, but remains a challenge. Here, a microscaffold cochlear electrode array (MiSCEA) consisting of a microfabricated flexible electrode array and a 3D microscaffold for steroid reservoir is reported. The MiSCEA without loaded drug is tested by measuring the electrically evoked auditory brainstem response of the cochlea in guinea pigs (n = 4). The scaffold is then coated with steroid (dexamethasone) encapsulated in polylactic-co-glycolic acid and the continuous release of the steroid into artificial perilymph during six weeks is monitored. The steroid-containing scaffolds are then implanted into guinea pigs (n = 4) and threshold shifts are analyzed for four weeks by measuring the acoustically evoked auditory brainstem response. The threshold shifts tend to be lower in the group implanted with the steroid-containing MiSCEAs. The feasibility of 3D MiSCEA opens up the development of potential next-generation cochlear electrode with improved steroid release dynamics into cochlea.
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Affiliation(s)
- Jongmoon Jang
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
- DGIST‐ETH Microrobot Research CenterDGIST Daegu 42988 Republic of Korea
- Microsystem LaboratoryÉcole Polytechnique Fédérale de Lausanne (EPFL) Lausanne CH‐1015 Switzerland
| | - Jin‐young Kim
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
- DGIST‐ETH Microrobot Research CenterDGIST Daegu 42988 Republic of Korea
| | - Yeong Cheol Kim
- Department of OtolaryngologyAjou University School of Medicine Suwon 16499 Republic of Korea
- Department of Biomedical SciencesBK21 Plus Research Center for Biomedical SciencesAjou University Graduate School of Medicine Suwon 16499 Republic of Korea
| | - Sangwon Kim
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
- DGIST‐ETH Microrobot Research CenterDGIST Daegu 42988 Republic of Korea
| | - Namsun Chou
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
| | - Seungmin Lee
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
- DGIST‐ETH Microrobot Research CenterDGIST Daegu 42988 Republic of Korea
| | - Yun‐Hoon Choung
- Department of OtolaryngologyAjou University School of Medicine Suwon 16499 Republic of Korea
- Department of Biomedical SciencesBK21 Plus Research Center for Biomedical SciencesAjou University Graduate School of Medicine Suwon 16499 Republic of Korea
| | - Sohee Kim
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
| | - Juergen Brugger
- Microsystem LaboratoryÉcole Polytechnique Fédérale de Lausanne (EPFL) Lausanne CH‐1015 Switzerland
| | - Hongsoo Choi
- Department of Robotics EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu 42988 Republic of Korea
- DGIST‐ETH Microrobot Research CenterDGIST Daegu 42988 Republic of Korea
| | - Jeong Hun Jang
- Department of OtolaryngologyAjou University School of Medicine Suwon 16499 Republic of Korea
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Glucocorticoid for Hearing Preservation After Cochlear Implantation: A Systemic Review and Meta-analysis of Animal Studies. Otol Neurotol 2019; 40:1178-1185. [DOI: 10.1097/mao.0000000000002383] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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The Effect of Systemic Steroid on Hearing Preservation After Cochlear Implantation via Round Window Approach: A Guinea Pig Model. Otol Neurotol 2017; 38:962-969. [DOI: 10.1097/mao.0000000000001453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Defining the Hook Region Anatomy of the Guinea Pig Cochlea for Modeling of Inner Ear Surgery. Otol Neurotol 2017; 38:e179-e187. [DOI: 10.1097/mao.0000000000001446] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Mauch Biomed H, Boyd P. ELECTRO-ACOUSTIC STIMULATION - AN OPTION WHEN HEARING AIDS ARE NOT ENOUGH. REVISTA MÉDICA CLÍNICA LAS CONDES 2016. [DOI: 10.1016/j.rmclc.2016.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Mauch H, Boyd P. TRADUCCIÓN ESTIMULACIÓN ELECTRO-ACÚSTICA UNA OPCIÓN CUANDO LOS AUDÍFONOS NO SON SUFICIENTE. REVISTA MÉDICA CLÍNICA LAS CONDES 2016. [DOI: 10.1016/j.rmclc.2016.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Effects of brain-derived neurotrophic factor (BDNF) on the cochlear nucleus in cats deafened as neonates. Hear Res 2016; 342:134-143. [PMID: 27773647 DOI: 10.1016/j.heares.2016.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/23/2016] [Accepted: 10/15/2016] [Indexed: 01/11/2023]
Abstract
Many previous studies have shown significant neurotrophic effects of intracochlear delivery of BDNF in preventing degeneration of cochlear spiral ganglion (SG) neurons after deafness in rodents and our laboratory has shown similar results in developing cats deafened prior to hearing onset. This study examined the morphology of the cochlear nucleus (CN) in a group of neonatally deafened cats from a previous study in which infusion of BDNF elicited a significant improvement in survival of the SG neurons. Five cats were deafened by systemic injections of neomycin sulfate (60 mg/kg, SQ, SID) starting one day after birth, and continuing for 16-18 days until auditory brainstem response (ABR) testing demonstrated profound bilateral hearing loss. The animals were implanted unilaterally at about 1 month of age using custom-designed electrodes with a drug-delivery cannula connected to an osmotic pump. BDNF (94 μg/ml; 0.25 μl/hr) was delivered for 10 weeks. The animals were euthanized and studied at 14-23 weeks of age. Consistent with the neurotrophic effects of BDNF on SG survival, the total CN volume in these animals was significantly larger on the BDNF-treated side than on the contralateral side. However, total CN volume, both ipsi- and contralateral to the implants in these deafened juvenile animals, was markedly smaller than the CN in normal adult animals, reflecting the severe effects of deafness on the central auditory system during development. Data from the individual major CN subdivisions (DCN, Dorsal Cochlear Nucleus; PVCN, Posteroventral Cochlear Nucleus; AVCN, Anteroventral Cochlear Nucleus) also were analyzed. A significant difference was observed between the BDNF-treated and control sides only in the AVCN. Measurements of the cross-sectional areas of spherical cells showed that cells were significantly larger in the AVCN ipsilateral to the implant than on the contralateral side. Further, the numerical density of spherical cells was significantly lower in the AVCN ipsilateral to the implant than on the contralateral side, consistent with the larger AVCN volume observed with BDNF treatment. Together, findings indicate significant neurotrophic effects of intracochlear BDNF infusion on the developing CN.
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The Impact of Electrode Array Length on Hearing Preservation in Cochlear Implantation. Otol Neurotol 2016; 37:1006-15. [DOI: 10.1097/mao.0000000000001110] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Park M, Lee HS, Kim H, Oh SH, Lee JH, Suh MW. Differences in perilymphatic space enhancement and adverse inflammatory reaction after intratympanic injection of two different gadolinium agents: A 9.4-T magnetic resonance imaging study. Hear Res 2016; 333:118-126. [PMID: 26795351 DOI: 10.1016/j.heares.2015.10.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/30/2015] [Accepted: 10/14/2015] [Indexed: 09/30/2022]
Abstract
PURPOSE To compare the inner ear enhancement after intratympanic injection of two widely used gadolinium (Gd) agents by 9.4 T micro-magnetic resonance imaging (MRI) and to investigate the effects of Gd on the inner ear. METHODS Twelve ears of six rats received intratympanic administration of 1/5 diluted Gd agents: gadoterate meglumine (Gd-DTPA) for the left ear and gadodiamide (Gd-DTPA-BMA) for the right ear. MRI was performed every 30 min from 1 to 4 h after administration. The normalized signal intensity was evaluated by quantitative analysis at each cochlear fluid compartment. Eight, six, and seven ears treated with Gd-DTPA, Gd-DPTA-BMA, and nothing as controls, respectively, were processed for histological evaluation after MRI. After hematoxylin & eosin staining, adverse inflammatory reactions were evaluated for turbid aggregation and lymphocytes. RESULTS The perilymphatic enhancement of Gd-DTPA was superior to that of Gd-DTPA-BMA regardless of cochlear turn, compartment, and time point. Inflammatory reactions were found in 4/8 (50.0%) and 4/6 (66.6%) ears administered Gd-DTPA and Gd-DTPA-BMA, respectively. Regardless of the contrast agent used, inflammatory reactions were most definite in the scala tympani of the basal turn, i.e., near the round window. Slightly greater inflammatory reactions were observed in ears injected with Gd-DTPA-BMA compared to Gd-DTPA although the difference was not statistically significant. No inflammatory reaction was observed in any of the seven controls. The auditory brainstem response threshold was 11.8 ± 2.5 dB SPL before IT Gd injection and it did not change for up to 5 days (15.4 ± 6.6 dB SPL) post-injection. CONCLUSIONS Gd-DTPA was superior to Gd-DTPA-BMA for visualization of the inner ear. Administration of diluted Gd agents intratympanically may induce considerable inflammatory reactions in the inner ear.
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Affiliation(s)
- Mina Park
- Department of Otorhinolaryngology-Head and Neck Surgery and Healthcare Research Institute, Healthcare System Gangnam Center, Seoul National University Hospital, Seoul, Republic of Korea; Department of Translational Biomedical Research, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ho Sun Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea
| | - Hyeonjin Kim
- Radiology, Seoul National University Hospital, Seoul, Republic of Korea; Department of Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Republic of Korea; Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Jun Ho Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Republic of Korea; Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Myung-Whan Suh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea; Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea.
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