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Huang Y, Yao K, Zhang Q, Huang X, Chen Z, Zhou Y, Yu X. Bioelectronics for electrical stimulation: materials, devices and biomedical applications. Chem Soc Rev 2024; 53:8632-8712. [PMID: 39132912 DOI: 10.1039/d4cs00413b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Bioelectronics is a hot research topic, yet an important tool, as it facilitates the creation of advanced medical devices that interact with biological systems to effectively diagnose, monitor and treat a broad spectrum of health conditions. Electrical stimulation (ES) is a pivotal technique in bioelectronics, offering a precise, non-pharmacological means to modulate and control biological processes across molecular, cellular, tissue, and organ levels. This method holds the potential to restore or enhance physiological functions compromised by diseases or injuries by integrating sophisticated electrical signals, device interfaces, and designs tailored to specific biological mechanisms. This review explains the mechanisms by which ES influences cellular behaviors, introduces the essential stimulation principles, discusses the performance requirements for optimal ES systems, and highlights the representative applications. From this review, we can realize the potential of ES based bioelectronics in therapy, regenerative medicine and rehabilitation engineering technologies, ranging from tissue engineering to neurological technologies, and the modulation of cardiovascular and cognitive functions. This review underscores the versatility of ES in various biomedical contexts and emphasizes the need to adapt to complex biological and clinical landscapes it addresses.
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Affiliation(s)
- Ya Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Kuanming Yao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Qiang Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Xingcan Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Zhenlin Chen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Yu Zhou
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Xinge Yu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
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2
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Nieratschker M, Yildiz E, Gerlitz M, Bera S, Gadenstaetter AJ, Kramer AM, Kwiatkowska M, Mistrik P, Landegger LD, Braun S, Schlingensiepen R, Honeder C, Arnoldner C, Rommelspacher H. A preoperative dose of the pyridoindole AC102 improves the recovery of residual hearing in a gerbil animal model of cochlear implantation. Cell Death Dis 2024; 15:531. [PMID: 39060244 PMCID: PMC11282255 DOI: 10.1038/s41419-024-06854-9] [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: 02/08/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024]
Abstract
Sensorineural hearing loss (SNHL) is the most common sensory deficit worldwide. Due to the heterogeneity of causes for SNHL, effective treatment options remain scarce, creating an unmet need for novel drugs in the field of otology. Cochlear implantation (CI) currently is the only established method to restore hearing function in profound SNHL and deaf patients. The cochlear implant bypasses the non-functioning sensory hair cells (HCs) and electrically stimulates the neurons of the cochlear nerve. CI also benefits patients with residual hearing by combined electrical and auditory stimulation. However, the insertion of an electrode array into the cochlea induces an inflammatory response, characterized by the expression of pro-inflammatory cytokines, upregulation of reactive oxygen species, and apoptosis and necrosis of HCs, putting residual hearing at risk. Here, we characterize the small molecule AC102, a pyridoindole, for its protective effects on residual hearing in CI. In a gerbil animal model of CI, AC102 significantly improves the recovery of hearing thresholds across multiple frequencies and confines the cochlear trauma to the directly mechanically injured area. In addition, AC102 significantly preserves auditory nerve fibers and inner HC synapses throughout the whole cochlea. In vitro experiments in an ethanol challenged HT22 cell-line revealed significant and dose-responsive anti-apoptotic effects following the treatment of with AC102. Further, AC102 treatment resulted in significant downregulation of the expression of pro-inflammatory cytokines in an organotypic ex vivo model of electrode insertion trauma (EIT). These results suggest that AC102's effects are likely elicited during the inflammatory phase of EIT and mediated by anti-apoptotic and anti-inflammatory properties, highlighting AC102 as a promising compound for hearing preservation during CI. Moreover, since the inflammatory response in CI shares similarities to that in other etiologies of SNHL, AC102 may be inferred as a potential general treatment option for various inner ear conditions.
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Affiliation(s)
- Michael Nieratschker
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Erdem Yildiz
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Matthias Gerlitz
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | | | - Anselm J Gadenstaetter
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Anne-Margarethe Kramer
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria
| | | | | | - Lukas D Landegger
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | | | | | - Clemens Honeder
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Christoph Arnoldner
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
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3
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Fleet A, Nikookam Y, Radotra A, Gowrishankar S, Metcalfe C, Muzaffar J, Smith ME, Monksfield P, Bance M. Outcomes following cochlear implantation with eluting electrodes: A systematic review. Laryngoscope Investig Otolaryngol 2024; 9:e1263. [PMID: 38855776 PMCID: PMC11160184 DOI: 10.1002/lio2.1263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 02/22/2024] [Accepted: 04/25/2024] [Indexed: 06/11/2024] Open
Abstract
Objectives To establish audiological and other outcomes following cochlear implantation in humans and animals with eluting electrodes. Methods Systematic review and narrative synthesis. Databases searched (April 2023): MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov, and Web of Science. Studies reporting outcomes in either humans or animals following cochlear implantation with a drug-eluting electrode were included. No limits were placed on language or year of publication. Risk of bias assessment was performed on all included studies using either the Brazzelli or Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) assessment tools. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. Results Searches identified 146 abstracts and 108 full texts. Of these, 18 studies met the inclusion criteria, reporting outcomes in 523 animals (17 studies) and 24 humans (1 study). Eluting electrodes included dexamethasone (16 studies), aracytine (1 study), nicotinamide adenine dinucleotide (1 study), the growth factors insulin-like growth factor 1 (IGF1) and hepatocyte growth factor (HGF) (1 study), and neurotrophin-3 (1 study). All included studies compare outcomes following implantation with an eluting electrode with a control non-eluting electrode. In the majority of studies, audiological outcomes (e.g., auditory brainstem response threshold) were superior following implantation with an eluting electrode compared with a standard electrode. Most studies which investigated post-implantation impedance reported lower impedance following implantation with an eluting electrode. The influence of eluting electrodes on other reported outcomes (including post-implantation cochlear fibrosis and the survival of hair cells and spiral ganglion neurons) was more varied across the included studies. Conclusions Eluting electrodes have shown promise in animal studies in preserving residual hearing following cochlear implantation and in reducing impedance, though data from human studies remain lacking. Further in-human studies will be required to determine the clinical usefulness of drug-eluting cochlear implants as a future treatment for sensorineural hearing loss.
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Affiliation(s)
- Alex Fleet
- Department of Clinical Neurosciences, Addenbrooke's Health CampusUniversity of CambridgeCambridgeUK
| | - Yasmin Nikookam
- Department of Ear, Nose and Throat SurgeryUniversity Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital Birmingham, Mindelsohn WayEdgbastonBirminghamUK
| | - Anshul Radotra
- The Royal Wolverhampton NHS Trust New Cross HospitalWolverhamptonUK
| | - Shravan Gowrishankar
- Department of Clinical Neurosciences, Addenbrooke's Health CampusUniversity of CambridgeCambridgeUK
| | | | - Jameel Muzaffar
- Department of Clinical Neurosciences, Addenbrooke's Health CampusUniversity of CambridgeCambridgeUK
- Department of Ear, Nose and Throat SurgeryUniversity Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital Birmingham, Mindelsohn WayEdgbastonBirminghamUK
| | - Matthew E. Smith
- Department of Clinical Neurosciences, Addenbrooke's Health CampusUniversity of CambridgeCambridgeUK
| | - Peter Monksfield
- Department of Ear, Nose and Throat SurgeryUniversity Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital Birmingham, Mindelsohn WayEdgbastonBirminghamUK
| | - Manohar Bance
- Department of Clinical Neurosciences, Addenbrooke's Health CampusUniversity of CambridgeCambridgeUK
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Rahman MT, Mostaert BJ, Hunger B, Saha U, Claussen AD, Razu I, Nasrin F, Khan NA, Eckard P, Coleman S, Oleson J, Kirk JR, Hirose K, Hansen MR. Contribution of macrophages to neural survival and intracochlear tissue remodeling responses following cochlear implantation. J Neuroinflammation 2023; 20:266. [PMID: 37974203 PMCID: PMC10652501 DOI: 10.1186/s12974-023-02955-y] [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: 06/12/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023] Open
Abstract
BACKGROUND Cochlear implants (CIs) restore hearing to deafened patients. The foreign body response (FBR) following cochlear implantation (post-CI) comprises an infiltration of macrophages, other immune and non-immune cells, and fibrosis into the scala tympani, a space that is normally devoid of cells. This FBR is associated with negative effects on CI outcomes including increased electrode impedances and loss of residual acoustic hearing. This study investigates the extent to which macrophage depletion by an orally administered CSF-1R specific kinase (c-FMS) inhibitor, PLX-5622, modulates the tissue response to CI and neural health. MAIN TEXT 10- to 12-week-old CX3CR1 + /GFP Thy1 + /YFP mice on C57BL/6J/B6 background was fed chow containing 1200 mg/kg PLX5622 or control chow for the duration of the study. 7 days after starting the diet, 3-channel cochlear implants were implanted in the ear via the round window. Serial impedance and neural response telemetry (NRT) measurements were acquired throughout the study. Electric stimulation began 7 days post-CI until 28 days post-CI for 5 h/day, 5 days/week, with programming guided by NRT and behavioral responses. Cochleae harvested at 10, 28 or 56 days post-CI were cryosectioned and labeled with an antibody against α-smooth muscle actin (α-SMA) to identify myofibroblasts and quantify the fibrotic response. Using IMARIS image analysis software, the outlines of scala tympani, Rosenthal canal, modiolus, and lateral wall for each turn were traced manually to measure region volume. The density of nuclei, CX3CR1 + macrophages, Thy1 + spiral ganglion neuron (SGN) numbers, and the ratio of the α-SMA + volume/scala tympani volume were calculated. Cochlear implantation in control diet subjects caused infiltration of cells, including macrophages, into the cochlea. Fibrosis was evident in the scala tympani adjacent to the electrode array. Mice fed PLX5622 chow showed reduced macrophage infiltration throughout the implanted cochleae across all time points. However, scala tympani fibrosis was not reduced relative to control diet subjects. Further, mice treated with PLX5622 showed increased electrode impedances compared to controls. Finally, treatment with PLX5622 decreased SGN survival in implanted and contralateral cochleae. CONCLUSION The data suggest that macrophages play an important role in modulating the intracochlear tissue response following CI and neural survival.
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Affiliation(s)
- Muhammad Taifur Rahman
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Brian J Mostaert
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Bryce Hunger
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Utsow Saha
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Alexander D Claussen
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Ibrahim Razu
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Farjana Nasrin
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Nashwaan Ali Khan
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Peter Eckard
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Sarah Coleman
- Department of Biostatistics, The University of Iowa, Iowa City, IA, USA
| | - Jacob Oleson
- Department of Biostatistics, The University of Iowa, Iowa City, IA, USA
| | | | - Keiko Hirose
- Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, Iowa City, IA, 52242, USA.
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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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Tessler I, Gecel NA, Glicksberg BS, Shivatzki S, Shapira Y, Zimlichman E, Alon EE, Klang E, Wolfovitz A. A Five-Decade Text Mining Analysis of Cochlear Implant Research: Where We Started and Where We Are Heading. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1891. [PMID: 38003940 PMCID: PMC10673015 DOI: 10.3390/medicina59111891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/09/2023] [Accepted: 10/19/2023] [Indexed: 11/26/2023]
Abstract
Background and Objectives: Since its invention in the 1970s, the cochlear implant (CI) has been substantially developed. We aimed to assess the trends in the published literature to characterize CI. Materials and Methods: We queried PubMed for all CI-related entries published during 1970-2022. The following data were extracted: year of publication, publishing journal, title, keywords, and abstract text. Search terms belonged to the patient's age group, etiology for hearing loss, indications for CI, and surgical methodological advancement. Annual trends of publications were plotted. The slopes of publication trends were calculated by fitting regression lines to the yearly number of publications. Results: Overall, 19,428 CIs articles were identified. Pediatric-related CI was the most dominant sub-population among the age groups, with the highest rate and slope during the years (slope 5.2 ± 0.3, p < 0.001), while elderly-related CIs had significantly fewer publications. Entries concerning hearing preservation showed the sharpest rise among the methods, from no entries in 1980 to 46 entries in 2021 (slope 1.7 ± 0.2, p < 0.001). Entries concerning robotic surgery emerged in 2000, with a sharp increase in recent years (slope 0.5 ± 0.1, p < 0.001). Drug-eluting electrodes and CI under local-anesthesia have been reported only in the past five years, with a gradual rise. Conclusions: Publications regarding CI among pediatrics outnumbered all other indications, supporting the rising, pivotal role of CI in the rehabilitation of children with sensorineural hearing loss. Hearing-preservation publications have recently rapidly risen, identified as the primary trend of the current era, followed by a sharp rise of robotic surgery that is evolving and could define the next revolution.
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Affiliation(s)
- Idit Tessler
- Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, Ramat Gan 52621, Israel (S.S.); (Y.S.); (E.E.A.); (A.W.)
- ARC Innovation Center, Sheba Medical Center, Ramat Gan 52621, Israel; (E.Z.); (E.K.)
| | - Nir A. Gecel
- Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, Ramat Gan 52621, Israel (S.S.); (Y.S.); (E.E.A.); (A.W.)
| | - Benjamin S. Glicksberg
- Hasso Plattner Institute for Digital Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Shaked Shivatzki
- Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, Ramat Gan 52621, Israel (S.S.); (Y.S.); (E.E.A.); (A.W.)
| | - Yisgav Shapira
- Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, Ramat Gan 52621, Israel (S.S.); (Y.S.); (E.E.A.); (A.W.)
| | - Eyal Zimlichman
- ARC Innovation Center, Sheba Medical Center, Ramat Gan 52621, Israel; (E.Z.); (E.K.)
| | - Eran E. Alon
- Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, Ramat Gan 52621, Israel (S.S.); (Y.S.); (E.E.A.); (A.W.)
| | - Eyal Klang
- ARC Innovation Center, Sheba Medical Center, Ramat Gan 52621, Israel; (E.Z.); (E.K.)
- Hasso Plattner Institute for Digital Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Amit Wolfovitz
- Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, Ramat Gan 52621, Israel (S.S.); (Y.S.); (E.E.A.); (A.W.)
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7
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Delaney DS, Liew LJ, Lye J, Atlas MD, Wong EYM. Overcoming barriers: a review on innovations in drug delivery to the middle and inner ear. Front Pharmacol 2023; 14:1207141. [PMID: 37927600 PMCID: PMC10620978 DOI: 10.3389/fphar.2023.1207141] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 10/02/2023] [Indexed: 11/07/2023] Open
Abstract
Despite significant advances in the development of therapeutics for hearing loss, drug delivery to the middle and inner ear remains a challenge. As conventional oral or intravascular administration are ineffective due to poor bioavailability and impermeability of the blood-labyrinth-barrier, localized delivery is becoming a preferable approach for certain drugs. Even then, localized delivery to the ear precludes continual drug delivery due to the invasive and potentially traumatic procedures required to access the middle and inner ear. To address this, the preclinical development of controlled release therapeutics and drug delivery devices have greatly advanced, with some now showing promise clinically. This review will discuss the existing challenges in drug development for treating the most prevalent and damaging hearing disorders, in particular otitis media, perforation of the tympanic membrane, cholesteatoma and sensorineural hearing loss. We will then address novel developments in drug delivery that address these including novel controlled release therapeutics such as hydrogel and nanotechnology and finally, novel device delivery approaches such as microfluidic systems and cochlear prosthesis-mediated delivery. The aim of this review is to investigate how drugs can reach the middle and inner ear more efficiently and how recent innovations could be applied in aiding drug delivery in certain pathologic contexts.
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Affiliation(s)
- Derek S. Delaney
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA, Australia
- Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia
| | - Lawrence J. Liew
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA, Australia
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA, Australia
| | - Joey Lye
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA, Australia
| | - Marcus D. Atlas
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA, Australia
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA, Australia
- Faculty of Health Sciences, Curtin Medical School, Curtin University, Bentley, WA, Australia
| | - Elaine Y. M. Wong
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA, Australia
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA, Australia
- Faculty of Health Sciences, Curtin Medical School, Curtin University, Bentley, WA, Australia
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8
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de Rijk SR, Boys AJ, Roberts IV, Jiang C, Garcia C, Owens RM, Bance M. Tissue-Engineered Cochlear Fibrosis Model Links Complex Impedance to Fibrosis Formation for Cochlear Implant Patients. Adv Healthc Mater 2023; 12:e2300732. [PMID: 37310792 DOI: 10.1002/adhm.202300732] [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: 03/07/2023] [Revised: 05/30/2023] [Indexed: 06/15/2023]
Abstract
Cochlear implants are a life-changing technology for those with severe sensorineural hearing loss, partially restoring hearing through direct electrical stimulation of the auditory nerve. However, they are known to elicit an immune response resulting in fibrotic tissue formation in the cochlea that is linked to residual hearing loss and suboptimal outcomes. Intracochlear fibrosis is difficult to track without postmortem histology, and no specific electrical marker for fibrosis exists. In this study, a tissue-engineered model of cochlear fibrosis is developed following implant placement to examine the electrical characteristics associated with fibrotic tissue formation around electrodes. The model is characterized using electrochemical impedance spectroscopy and an increase in the resistance and a decrease in capacitance of the tissue using a representative circuit are found. This result informs a new marker of fibrosis progression over time that is extractable from voltage waveform responses, which can be directly measured in cochlear implant patients. This marker is tested in a small sample size of recently implanted cochlear implant patients, showing a significant increase over two postoperative timepoints. Using this system, complex impedance is demonstrated as a marker of fibrosis progression that is directly measurable from cochlear implants to enable real-time tracking of fibrosis formation in patients, creating opportunities for earlier treatment intervention to improve cochlear implant efficacy.
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Affiliation(s)
- Simone R de Rijk
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 3 EB, UK
| | - Alexander J Boys
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Iwan V Roberts
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 3 EB, UK
| | - Chen Jiang
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 3 EB, UK
- Department of Electronic Engineering, Tsinghua University, Beijing, 100190, P. R. China
| | - Charlotte Garcia
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
| | - Róisín M Owens
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Manohar Bance
- Cambridge Hearing Group, Cambridge, CB2 8AF, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 3 EB, UK
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Braack KJ, Miles T, Amat F, Brown DJ, Atlas MD, Kuthubutheen J, Mulders WH, Prêle CM. Using x-ray micro computed tomography to quantify intracochlear fibrosis after cochlear implantation in a Guinea pig model. Heliyon 2023; 9:e19343. [PMID: 37662829 PMCID: PMC10474428 DOI: 10.1016/j.heliyon.2023.e19343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/07/2023] [Accepted: 08/18/2023] [Indexed: 09/05/2023] Open
Abstract
Cochlear implants (CIs) allow individuals with profound hearing loss to understand speech and perceive sounds. However, not all patients obtain the full benefits that CIs can provide and the cause of this disparity is not fully understood. One possible factor for the variability in outcomes after cochlear implantation, is the development of fibrotic scar tissue around the implanted electrode. It has been hypothesised that limiting the extent of fibrosis after implantation may improve overall CI function, and longevity of the device. Currently, histology is often used to quantify the extent of intracochlear tissue growth after implantation however this method is labour intensive, time-consuming, often involves significant user bias, and causes physical distortion of the fibrosis. Therefore, this study aimed to evaluate x-ray micro computed tomography (μCT) as a method to measure the amount and distribution of fibrosis in a guinea pig model of cochlear implantation. Adult guinea pigs were implanted with an inactive electrode, and cochleae harvested eight weeks later (n = 7) and analysed using μCT, to quantify the extent of tissue reaction, followed by histological analysis to confirm that the tissue was indeed fibrotic. Cochleae harvested from an additional six animals following implantation were analysed by μCT, before and after contrast staining with osmium tetroxide (OsO4), to enhance the visualisation of soft tissues within the cochlea, including the tissue reaction. Independent analysis by two observers showed that the quantification method was robust and provided additional information on the distribution of the response within the cochlea. Histological analysis revealed that μCT visualised dense collagenous material and new bone formation but did not capture loose, areolar fibrotic tissue. Treatment with OsO4 significantly enhanced the visible tissue reaction detected using μCT. Overall, μCT is an alternative and reliable method that can be used to quantify the extent of the CI-induced intracochlear tissue response and will be a useful tool for the in vivo assessment of novel anti-fibrotic treatments.
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Affiliation(s)
- Kady J. Braack
- School of Human Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Tylah Miles
- Institute for Respiratory Health, University of Western Australia, Nedlands, WA 6009, Australia
| | - Farah Amat
- School of Human Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Daniel J. Brown
- Curtin Medical School, Curtin University, Bentley, WA 6102, Australia
| | - Marcus D. Atlas
- Curtin Medical School, Curtin University, Bentley, WA 6102, Australia
- Medical School, University of Western Australia, Crawley, WA 6009, Australia
- Ear Science Institute Australia, Subiaco, WA 6008, Australia
| | - Jafri Kuthubutheen
- Medical School, University of Western Australia, Crawley, WA 6009, Australia
- Department of Otolaryngology Head and Neck Surgery, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009, Australia
| | | | - Cecilia M. Prêle
- Institute for Respiratory Health, University of Western Australia, Nedlands, WA 6009, Australia
- Ear Science Institute Australia, Subiaco, WA 6008, Australia
- School of Medical, Molecular and Forensic Sciences, Murdoch University, Murdoch, WA 6150, Australia
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10
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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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11
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Ernst BP, Heinrich UR, Fries M, Meuser R, Rader T, Eckrich J, Stauber RH, Strieth S. Cochlear implantation impairs intracochlear microcirculation and counteracts iNOS induction in guinea pigs. Front Cell Neurosci 2023; 17:1189980. [PMID: 37448696 PMCID: PMC10336219 DOI: 10.3389/fncel.2023.1189980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 06/06/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction Preservation of residual hearing remains a great challenge during cochlear implantation. Cochlear implant (CI) electrode array insertion induces changes in the microvasculature as well as nitric oxide (NO)-dependent vessel dysfunction which have been identified as possible mediators of residual hearing loss after cochlear implantation. Methods A total of 24 guinea pigs were randomized to receive either a CI (n = 12) or a sham procedure (sham) by performing a cochleostomy without electrode array insertion (n = 12). The hearing threshold was determined using frequency-specific compound action potentials. To gain visual access to the stria vascularis, a microscopic window was created in the osseous cochlear lateral wall. Cochlear blood flow (CBF) and cochlear microvascular permeability (CMP) were evaluated immediately after treatment, as well as after 1 and 2 h, respectively. Finally, cochleae were resected for subsequent immunohistochemical analysis of the iNOS expression. Results The sham control group showed no change in mean CBF after 1 h (104.2 ± 0.7%) and 2 h (100.8 ± 3.6%) compared to baseline. In contrast, cochlear implantation resulted in a significant continuous decrease in CBF after 1 h (78.8 ± 8.1%, p < 0.001) and 2 h (60.6 ± 11.3%, p < 0.001). Additionally, the CI group exhibited a significantly increased CMP (+44.9% compared to baseline, p < 0.0001) and a significant increase in median hearing threshold (20.4 vs. 2.5 dB SPL, p = 0.0009) compared to sham after 2 h. Intriguingly, the CI group showed significantly lower iNOS-expression levels in the organ of Corti (329.5 vs. 54.33 AU, p = 0.0003), stria vascularis (596.7 vs. 48.51 AU, p < 0.0001), interdental cells (564.0 vs. 109.1 AU, p = 0.0003) and limbus fibrocytes (119.4 vs. 18.69 AU, p = 0.0286). Conclusion Mechanical and NO-dependent microvascular dysfunction seem to play a pivotal role in residual hearing loss after CI electrode array insertion. This may be facilitated by the implantation associated decrease in iNOS expression. Therefore, stabilization of cochlear microcirculation could be a therapeutic strategy to preserve residual hearing.
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Affiliation(s)
| | - Ulf-Rüdiger Heinrich
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Mathias Fries
- Department of Otorhinolaryngology, University Medical Center Bonn (UKB), Bonn, Germany
| | - Regina Meuser
- Institute for Medical Biometry, Epidemiology and Informatics (IMBEI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Tobias Rader
- Division of Audiology, Department of Otorhinolaryngology, University Hospital, Ludwig-Maximilians-Universität München (LMU), Munich, Germany
| | - Jonas Eckrich
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Roland H. Stauber
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Sebastian Strieth
- Department of Otorhinolaryngology, University Medical Center Bonn (UKB), Bonn, Germany
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12
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Rahman MT, Mostaert BJ, Hunger B, Saha U, Claussen AD, Razu I, Farjana N, Khan NA, Coleman S, Oleson J, Kirk J, Keiko H, Hansen MR. Contribution of macrophages to intracochlear tissue remodeling responses following cochlear implantation and neural survival. RESEARCH SQUARE 2023:rs.3.rs-3065630. [PMID: 37461619 PMCID: PMC10350110 DOI: 10.21203/rs.3.rs-3065630/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2023]
Abstract
Introduction Cochlear implants (CIs) restore hearing to deafened patients. The foreign body response (FBR) following cochlear implantation (post-CI) comprises an infiltration of macrophages, other immune and non-immune cells, and fibrosis into the scala tympani; a space that is normally devoid of cells. This FBR is associated with negative effects on CI outcomes including increased electrode impedances and loss of residual acoustic hearing. This study investigates the extent to which macrophage depletion by an orally administered CSF-1R specific kinase (c-FMS) inhibitor, PLX-5622, modulates the tissue response to CI and neural health. Materials and methods 10-12-week-old CX3CR1+/GFP Thy1+/YFP mice on C57Bl6 background with normal hearing were fed chow containing 1200 mg/kg PLX5622 or control chow for the duration of the study. 7-days after starting the diet, 3-channel cochlear implants were implanted ear via the round window. Serial impedance and neural response telemetry (NRT) measurements were acquired throughout the study. Electric stimulation began 7 days post-CI until 28- days post-CI for 5 hrs/day, 5 days/week, with programming guided by NRT and behavioral responses. Cochleae harvested at 10-, 28- or 56-days post-CI were cryosectioned and labeled with antibody against α-smooth muscle actin (α-SMA) to identify myofibroblasts and quantify the fibrotic response. Using IMARIS image analysis software, the outlines of scala tympani, Rosenthal canal, modiolus and lateral wall for each turn were traced manually to measure region volume. Density of nuclei, CX3CR1+ macrophages, Thy1+ spiral ganglion neuron (SGN) numbers and ratio of volume of α-SMA+ space/volume of scala tympani were calculated. Results Cochlear implantation in control diet subjects caused infiltration of cells, including macrophages, into the cochlea: this response was initially diffuse throughout the cochlea and later localized to the scala tympani of the basal turn by 56-days post-CI. Fibrosis was evident in the scala tympani adjacent to the electrode array. Mice fed PLX5622 chow showed reduced macrophage infiltration throughout the implanted cochleae across all timepoints. However, scala tympani fibrosis was not reduced relative to control diet subjects. Further, mice treated with PLX5622 showed increased electrode impedances compared to controls. Finally, treatment with PLX5622 decreased SGN survival in implanted and contralateral cochleae. Discussion The data suggest that macrophages play an important role in modulating the intracochlear tissue response following CI and neural survival.
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Affiliation(s)
| | - Brain J Mostaert
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
| | - Bryce Hunger
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
| | - Utsow Saha
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
| | | | - Ibrahim Razu
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
| | - Nasrin Farjana
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
| | - Nashwaan Ali Khan
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
| | - Sarah Coleman
- Department of Statistics, The University of Iowa, IA
| | - Jackob Oleson
- Department of Statistics, The University of Iowa, IA
| | | | - Hirose Keiko
- Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St Louis, MO
| | - Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery, The University of Iowa, IA
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13
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Mau R, Eickner T, Jüttner G, Gao Z, Wei C, Fiedler N, Senz V, Lenarz T, Grabow N, Scheper V, Seitz H. Micro Injection Molding of Drug-Loaded Round Window Niche Implants for an Animal Model Using 3D-Printed Molds. Pharmaceutics 2023; 15:1584. [PMID: 37376033 DOI: 10.3390/pharmaceutics15061584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/16/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
A novel approach for the long-term medical treatment of the inner ear is the diffusion of drugs through the round window membrane from a patient-individualized, drug-eluting implant, which is inserted in the middle ear. In this study, drug-loaded (10 wt% Dexamethasone) guinea pig round window niche implants (GP-RNIs, ~1.30 mm × 0.95 mm × 0.60 mm) were manufactured with high precision via micro injection molding (µIM, Tmold = 160 °C, crosslinking time of 120 s). Each implant has a handle (~3.00 mm × 1.00 mm × 0.30 mm) that can be used to hold the implant. A medical-grade silicone elastomer was used as implant material. Molds for µIM were 3D printed from a commercially available resin (TG = 84 °C) via a high-resolution DLP process (xy resolution of 32 µm, z resolution of 10 µm, 3D printing time of about 6 h). Drug release, biocompatibility, and bioefficacy of the GP-RNIs were investigated in vitro. GP-RNIs could be successfully produced. The wear of the molds due to thermal stress was observed. However, the molds are suitable for single use in the µIM process. About 10% of the drug load (8.2 ± 0.6 µg) was released after 6 weeks (medium: isotonic saline). The implants showed high biocompatibility over 28 days (lowest cell viability ~80%). Moreover, we found anti-inflammatory effects over 28 days in a TNF-α-reduction test. These results are promising for the development of long-term drug-releasing implants for human inner ear therapy.
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Affiliation(s)
- Robert Mau
- Microfluidics, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Justus-von-Liebig Weg 6, 18059 Rostock, Germany
| | - Thomas Eickner
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Gábor Jüttner
- Kunststoff-Zentrum in Leipzig gGmbH (KUZ), Erich-Zeigner-Allee 44, 04229 Leipzig, Germany
| | - Ziwen Gao
- Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany
- Cluster of Excellence "Hearing4all", Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Chunjiang Wei
- Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany
- Cluster of Excellence "Hearing4all", Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Nicklas Fiedler
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Volkmar Senz
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Thomas Lenarz
- Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany
- Cluster of Excellence "Hearing4all", Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Niels Grabow
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
- Department Life, Light & Matter, Interdisciplinary Faculty, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
| | - Verena Scheper
- Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany
- Cluster of Excellence "Hearing4all", Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Hermann Seitz
- Microfluidics, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Justus-von-Liebig Weg 6, 18059 Rostock, Germany
- Department Life, Light & Matter, Interdisciplinary Faculty, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
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14
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Dinh CT, Chen S, Nourbakhsh A, Padgett K, Johnson P, Goncalves S, Bracho O, Bas E, Bohorquez J, Monje PV, Fernandez-Valle C, Elsayyad N, Liu X, Welford SM, Telischi F. Single Fraction and Hypofractionated Radiation Cause Cochlear Damage, Hearing Loss, and Reduced Viability of Merlin-Deficient Schwann Cells. Cancers (Basel) 2023; 15:2818. [PMID: 37345155 PMCID: PMC10216287 DOI: 10.3390/cancers15102818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 06/23/2023] Open
Abstract
BACKGROUND Vestibular schwannomas (VS) are benign intracranial tumors caused by loss of function of the merlin tumor suppressor. We tested three hypotheses related to radiation, hearing loss (HL), and VS cell survival: (1) radiation causes HL by injuring auditory hair cells (AHC), (2) fractionation reduces radiation-induced HL, and (3) single fraction and equivalent appropriately dosed multi-fractions are equally effective at controlling VS growth. We investigated the effects of single fraction and hypofractionated radiation on hearing thresholds in rats, cell death pathways in rat cochleae, and viability of human merlin-deficient Schwann cells (MD-SC). METHODS Adult rats received cochlear irradiation with single fraction (0 to 18 Gray [Gy]) or hypofractionated radiation. Auditory brainstem response (ABR) testing was performed for 24 weeks. AHC viabilities were determined using immunohistochemistry. Neonatal rat cochleae were harvested after irradiation, and gene- and cell-based assays were conducted. MD-SCs were irradiated, and viability assays and immunofluorescence for DNA damage and cell cycle markers were performed. RESULTS Radiation caused dose-dependent and progressive HL in rats and AHC losses by promoting expression of apoptosis-associated genes and proteins. When compared to 12 Gy single fraction, hypofractionation caused smaller ABR threshold and pure tone average shifts and was more effective at reducing MD-SC viability. CONCLUSIONS Investigations into the mechanisms of radiation ototoxicity and VS radiobiology will help determine optimal radiation regimens and identify potential therapies to mitigate radiation-induced HL and improve VS tumor control.
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Affiliation(s)
- Christine T. Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA (O.B.)
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Si Chen
- Department of Otolaryngology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Aida Nourbakhsh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA (O.B.)
| | - Kyle Padgett
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Radiology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Perry Johnson
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Stefania Goncalves
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA (O.B.)
| | - Olena Bracho
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA (O.B.)
| | - Esperanza Bas
- Department of Research Pharmacy, Sylvester Comprehensive Cancer Center, Miami, FL 33136, USA
| | - Jorge Bohorquez
- Department of Biomedical Engineering, University of Miami, Miami, FL 33146, USA
| | - Paula V. Monje
- Department of Neurosurgery, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Cristina Fernandez-Valle
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA;
| | - Nagy Elsayyad
- Allina Health Cancer Institute—Radiation Oncology, St. Paul, MN 55102, USA
| | - Xuezhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA (O.B.)
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Scott M. Welford
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Fred Telischi
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA (O.B.)
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami, Miami, FL 33146, USA
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15
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Talebian S, Mendes B, Conniot J, Farajikhah S, Dehghani F, Li Z, Bitoque D, Silva G, Naficy S, Conde J, Wallace GG. Biopolymeric Coatings for Local Release of Therapeutics from Biomedical Implants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207603. [PMID: 36782094 PMCID: PMC10131825 DOI: 10.1002/advs.202207603] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Indexed: 06/18/2023]
Abstract
The deployment of structures that enable localized release of bioactive molecules can result in more efficacious treatment of disease and better integration of implantable bionic devices. The strategic design of a biopolymeric coating can be used to engineer the optimal release profile depending on the task at hand. As illustrative examples, here advances in delivery of drugs from bone, brain, ocular, and cardiovascular implants are reviewed. These areas are focused to highlight that both hard and soft tissue implants can benefit from controlled localized delivery. The composition of biopolymers used to achieve appropriate delivery to the selected tissue types, and their corresponding outcomes are brought to the fore. To conclude, key factors in designing drug-loaded biopolymeric coatings for biomedical implants are highlighted.
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Affiliation(s)
- Sepehr Talebian
- School of Chemical and Biomolecular EngineeringThe University of SydneySydneyNSW2006Australia
- Nano Institute (Sydney Nano)The University of SydneySydneyNSW2006Australia
| | - Bárbara Mendes
- ToxOmicsNOVA Medical School|Faculdade de Ciências MédicasNMS|FCMUniversidade Nova de LisboaLisboa1169‐056Portugal
| | - João Conniot
- ToxOmicsNOVA Medical School|Faculdade de Ciências MédicasNMS|FCMUniversidade Nova de LisboaLisboa1169‐056Portugal
| | - Syamak Farajikhah
- School of Chemical and Biomolecular EngineeringThe University of SydneySydneyNSW2006Australia
- Nano Institute (Sydney Nano)The University of SydneySydneyNSW2006Australia
| | - Fariba Dehghani
- School of Chemical and Biomolecular EngineeringThe University of SydneySydneyNSW2006Australia
- Nano Institute (Sydney Nano)The University of SydneySydneyNSW2006Australia
| | - Zhongyan Li
- School of Chemical and Biomolecular EngineeringThe University of SydneySydneyNSW2006Australia
| | - Diogo Bitoque
- ToxOmicsNOVA Medical School|Faculdade de Ciências MédicasNMS|FCMUniversidade Nova de LisboaLisboa1169‐056Portugal
| | - Gabriela Silva
- ToxOmicsNOVA Medical School|Faculdade de Ciências MédicasNMS|FCMUniversidade Nova de LisboaLisboa1169‐056Portugal
| | - Sina Naficy
- School of Chemical and Biomolecular EngineeringThe University of SydneySydneyNSW2006Australia
- Nano Institute (Sydney Nano)The University of SydneySydneyNSW2006Australia
| | - João Conde
- ToxOmicsNOVA Medical School|Faculdade de Ciências MédicasNMS|FCMUniversidade Nova de LisboaLisboa1169‐056Portugal
| | - Gordon G. Wallace
- Intelligent Polymer Research InstituteARC Centre of Excellence for Electromaterials ScienceAIIM FacilityUniversity of WollongongSydneyNSW2522Australia
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16
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Dual Drug Delivery in Cochlear Implants: In Vivo Study of Dexamethasone Combined with Diclofenac or Immunophilin Inhibitor MM284 in Guinea Pigs. Pharmaceutics 2023; 15:pharmaceutics15030726. [PMID: 36986587 PMCID: PMC10058822 DOI: 10.3390/pharmaceutics15030726] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 02/24/2023] Open
Abstract
Cochlear implants are well established to treat severe hearing impairments. Despite many different approaches to reduce the formation of connective tissue after electrode insertion and to keep electrical impedances low, results are not yet satisfying. Therefore, the aim of the current study was to combine the incorporation of 5% dexamethasone in the silicone body of the electrode array with an additional polymeric coating releasing diclofenac or the immunophilin inhibitor MM284, some anti-inflammatory substances not yet tested in the inner ear. Guinea pigs were implanted for four weeks and hearing thresholds were determined before implantation and after the observation time. Impedances were monitored over time and, finally, connective tissue and the survival of spiral ganglion neurons (SGNs) were quantified. Impedances increased in all groups to a similar extent but this increase was delayed in the groups with an additional release of diclofenac or MM284. Using Poly-L-lactide (PLLA)-coated electrodes, the damage caused during insertion was much higher than without the coating. Only in these groups, connective tissue could extend to the apex of the cochlea. Despite this, numbers of SGNs were only reduced in PLLA and PLLA plus diclofenac groups. Even though the polymeric coating was not flexible enough, MM284 seems to especially have potential for further evaluation in connection with cochlear implantation.
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17
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Chen A, Chen D, Lv K, Li G, Pan J, Ma D, Tang J, Zhang H. Zwitterionic Polymer/Polydopamine Coating of Electrode Arrays Reduces Fibrosis and Residual Hearing Loss after Cochlear Implantation. Adv Healthc Mater 2023; 12:e2200807. [PMID: 36177664 DOI: 10.1002/adhm.202200807] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/15/2022] [Indexed: 02/03/2023]
Abstract
Since the first surgery 50 years ago, cochlear implantation (CI) is the major treatment for patients with severe sensorineural hearing loss. However, unexpected foreign body reactions (FBRs) after surgery are reported in 90% of CI recipients, resulting in the formation of fibrosis in the cochlea and progressive residual hearing loss. Zwitterion modification is universally used to reduce bio-fouling and suppress FBRs but never for CI. In the present study, a zwitterionic coating is developed, which is composed of poly sulfobetaine methacrylate (PSB) and polydopamine (PDA) for cochlear implants. The PSB-PDA coating shows a series of characters for an ideal anti-FBRs material, including super-hydrophilicity, low protein and cell adsorption, long-term stability, and high biocompatibility. Compared to the uncoated controls, PSB-PDA coating inhibits the activation of macrophages and reduces the release of inflammatory factors (TNF-α, IL-1β, NO) and fibrosis-related factors (TGF-β1, α-SMA, collagen I). PSB-PDA coated electrode arrays suppress fibrosis completely and preserve residual hearing significantly in rat CI models. These results suggest that PSB-PDA coating is a novel strategy for anti-fibrosis to improve the outcomes of CI.
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Affiliation(s)
- Anning Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.,Hearing Research Center, Southern Medical University, Guangzhou, 510282, China
| | - Dongxiu Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.,Hearing Research Center, Southern Medical University, Guangzhou, 510282, China
| | - Kai Lv
- Guangdong Provincial Engineering and Technological Research Center for Drug Carrier Development, Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou, 510632, China
| | - Guowei Li
- Department of Nuclear Medicine and PET/CT-MRI Center, the First Affiliated Hospital of Jinan University, Guangzhou, 510630, China
| | - Jing Pan
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.,Hearing Research Center, Southern Medical University, Guangzhou, 510282, China
| | - Dong Ma
- Guangdong Provincial Engineering and Technological Research Center for Drug Carrier Development, Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou, 510632, China
| | - Jie Tang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.,Hearing Research Center, Southern Medical University, Guangzhou, 510282, China.,Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.,Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, 510515, China
| | - Hongzheng Zhang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.,Hearing Research Center, Southern Medical University, Guangzhou, 510282, China
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18
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Gay RD, Enke YL, Kirk JR, Goldman DR. Therapeutics for hearing preservation and improvement of patient outcomes in cochlear implantation—Progress and possibilities. Hear Res 2022; 426:108637. [DOI: 10.1016/j.heares.2022.108637] [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: 12/09/2021] [Revised: 10/11/2022] [Accepted: 10/18/2022] [Indexed: 11/04/2022]
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19
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Rongthong T, Qnouch A, Gehrke MM, Danede F, Willart J, Oliveira P, Paccou L, Tourrel G, Stahl P, Verin J, Toulemonde P, Vincent C, Siepmann F, Siepmann J. Long term behavior of dexamethasone-loaded cochlear implants: In vitro & in vivo. Int J Pharm X 2022; 4:100141. [DOI: 10.1016/j.ijpx.2022.100141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/17/2022] [Accepted: 11/19/2022] [Indexed: 11/23/2022] Open
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20
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Chen A, Chen Y, Liu S, Ma D, Tang J, Zhang H. Mesoporous silica nanoparticle-modified electrode arrays of cochlear implants for delivery of siRNA-TGFβ1 into the inner ear. Colloids Surf B Biointerfaces 2022; 218:112753. [PMID: 35963142 DOI: 10.1016/j.colsurfb.2022.112753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/29/2022] [Accepted: 08/03/2022] [Indexed: 10/16/2022]
Abstract
Cochlear implants (CI) are widely used in patients to restore hearing function. Uncontrolled fibrosis in the cochleae induced by excess secretion of TGFβ1 seriously affects the effectiveness of CIs. siRNA is a potential therapeutic strategy to downregulate TGFβ1 specifically. However, treatment with siRNA in cochleae is difficult due to the poor penetration capability and instability of siRNA and the inaccessibility and vulnerability of cochleae. To address these challenges, we developed amino-functionalized mesoporous silica nanoparticle (MSN-NH2)-modified electrode arrays to deliver siRNA-TGFβ1 into the inner ear. The shape, diameter, pore diameter, and zeta potential of MSN-NH2 were investigated. siRNA loading capability and protective effect of MSN-NH2 were determined by agarose gel electrophoresis assay. The cytotoxicity, cellular uptake assay, and TGFβ1 knockdown efficiency of MSN-NH2 were studied by CCK-8 assay, flow cytometry, and real-time PCR, respectively. MSN-NH2-siTGFβ1 nanoparticles were absorbed into the electrode arrays and worked in the cochleae. MSN-NH2-siTGFβ1-modified CI electrode arrays may be an attractive therapeutic clinical intervention strategy to inhibit cochlear implantation fibrosis.
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Affiliation(s)
- Anning Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Hearing Research Center, Southern Medical University, Guangzhou 510282, China
| | - Yaoheng Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Hearing Research Center, Southern Medical University, Guangzhou 510282, China
| | - Shixin Liu
- Guangdong Provincial Engineering and Technological Research Center for Drug Carrier Development, Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou 510632, China
| | - Dong Ma
- Guangdong Provincial Engineering and Technological Research Center for Drug Carrier Development, Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou 510632, China.
| | - Jie Tang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Hearing Research Center, Southern Medical University, Guangzhou 510282, China; Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou 510515, China.
| | - Hongzheng Zhang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Hearing Research Center, Southern Medical University, Guangzhou 510282, China.
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21
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Plontke SK, Liebau A, Lehner E, Bethmann D, Mäder K, Rahne T. Safety and audiological outcome in a case series of tertiary therapy of sudden hearing loss with a biodegradable drug delivery implant for controlled release of dexamethasone to the inner ear. Front Neurosci 2022; 16:892777. [PMID: 36203796 PMCID: PMC9530574 DOI: 10.3389/fnins.2022.892777] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/16/2022] [Indexed: 11/21/2022] Open
Abstract
Background Intratympanic injections of glucocorticoids have become increasingly common in the treatment of idiopathic sudden sensorineural hearing loss (ISSHL). However, due to their fast elimination, sustained applications have been suggested for local drug delivery to the inner ear. Materials and methods The study is based on a retrospective chart review of patients treated for ISSHL at a single tertiary (university) referral center. We included patients who were treated with a solid, biodegradable, poly(D,L-lactic-co-glycolic acid) (PLGA)-based drug delivery system providing sustained delivery of dexamethasone extracochlear into the round window niche (n = 15) or intracochlear into scala tympani (n = 2) for tertiary therapy of ISSHL in patients without serviceable hearing after primary systemic and secondary intratympanic glucocorticoid therapy. We evaluated the feasibility and safety through clinical evaluation, histological examination, and functional tests [pure-tone threshold (PTA), word recognition scores (WRS)]. Results With adequate surgical preparation of the round window niche, implantation was feasible in all patients. Histologic examination of the material in the round window niche showed signs of resorption without relevant inflammation or foreign body reaction to the implant. In patients where the basal part of scala tympani was assessable during later cochlear implantation, no pathological findings were found. In the patients with extracochlear application, average preoperative PTA was 84.7 dB HL (SD: 20.0) and 76.7 dB HL (SD: 16.7) at follow-up (p = 0.08). The preoperative average maximum WRS was 14.6% (SD: 17.9) and 39.3% (SD: 30.7) at follow-up (p = 0.11). Six patients (40%), however, reached serviceable hearing. The two patients with intracochlear application did not improve. Conclusion The extracochlear application of the controlled release system in the round window niche and – based on limited observations - intracochlear implantation into scala tympani appears feasible and safe. Due to the uncontrolled study design, conclusions about the efficacy of the treatment are limited. These observations, however, may encourage the initiation of prospective controlled studies using biodegradable controlled release implants as drug delivery systems for the treatment of inner ear diseases.
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Affiliation(s)
- Stefan K. Plontke
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
- *Correspondence: Stefan K. Plontke,
| | - Arne Liebau
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Eric Lehner
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Daniel Bethmann
- Institute of Pathology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Karsten Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Torsten Rahne
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
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22
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The Augmented Cochlear Implant: a Convergence of Drugs and Cochlear Implantation for the Treatment of Hearing Loss. CURRENT OTORHINOLARYNGOLOGY REPORTS 2022. [DOI: 10.1007/s40136-022-00426-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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23
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Reiss LA, Kirk J, Claussen AD, Fallon JB. Animal Models of Hearing Loss after Cochlear Implantation and Electrical Stimulation. Hear Res 2022; 426:108624. [DOI: 10.1016/j.heares.2022.108624] [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: 09/24/2021] [Revised: 03/28/2022] [Accepted: 09/23/2022] [Indexed: 11/04/2022]
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24
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Goyal MM, Zhou NJ, Vincent PFY, Hoffman ES, Goel S, Wang C, Sun DQ. Rationally Designed Magnetic Nanoparticles for Cochlear Drug Delivery: Synthesis, Characterization, and In Vitro Biocompatibility in a Murine Model. OTOLOGY & NEUROTOLOGY OPEN 2022; 2:e013. [PMID: 38516629 PMCID: PMC10950169 DOI: 10.1097/ono.0000000000000013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/03/2022] [Indexed: 03/23/2024]
Abstract
Hypothesis Magnetic nanoparticles (MNPs) for cochlear drug delivery can be precisely engineered for biocompatibility in the cochlea. Background MNPs are promising drug delivery vehicles that can enhance the penetration of both small and macromolecular therapeutics into the cochlea. However, concerns exist regarding the application of oxidative, metal-based nanomaterials to delicate sensory tissues of the inner ear. Translational development of MNPs for cochlear drug deliver requires specifically tuned nanoparticles that are not cytotoxic to inner ear tissues. We describe the synthesis and characterization of precisely tuned MNP vehicles, and their in vitro biocompatibility in murine organ of Corti organotypic cultures. Methods MNPs were synthesized via 2-phase ligand transfer process with precise control of nanoparticle size. Core and hydrodynamic sizes of nanoparticles were characterized using electron microscopy and dynamic light scattering, respectively. In vitro biocompatibility was assayed via mouse organ of Corti organotypic cultures with and without an external magnetic field gradient. Imaging was performed using immunohistochemical labeling and confocal microscopy. Outer hair cell, inner hair cell, and spiral ganglion neurites were individually quantified. Results Monocore PEG-MNPs of 45 and 148 nm (mean hydrodynamic diameter) were synthesized. Organ of Corti cultures demonstrated preserved outer hair cell, inner hair cell, and neurite counts across 2 MNP sizes and doses, and irrespective of external magnetic field gradient. Conclusion MNPs can be custom-synthesized with precise coating, size, and charge properties specific for cochlear drug delivery while also demonstrating biocompatibility in vitro.
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Affiliation(s)
- Mukund M. Goyal
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD
| | - Nancy J. Zhou
- School of Medicine, Johns Hopkins University, Baltimore, MD
| | - Philippe F. Y. Vincent
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University, Baltimore, MD
| | - Elina S. Hoffman
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD
| | - Shiv Goel
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD
| | - Chao Wang
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD
| | - Daniel Q. Sun
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University, Baltimore, MD
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25
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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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26
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Ertas YN, Ozpolat D, Karasu SN, Ashammakhi N. Recent Advances in Cochlear Implant Electrode Array Design Parameters. MICROMACHINES 2022; 13:1081. [PMID: 35888898 PMCID: PMC9323156 DOI: 10.3390/mi13071081] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 02/04/2023]
Abstract
Cochlear implants are neural implant devices that aim to restore hearing in patients with severe sensorineural hearing impairment. Here, the main goal is to successfully place the electrode array in the cochlea to stimulate the auditory nerves through bypassing damaged hair cells. Several electrode and electrode array parameters affect the success of this technique, but, undoubtedly, the most important one is related to electrodes, which are used for nerve stimulation. In this paper, we provide a comprehensive resource on the electrodes currently being used in cochlear implant devices. Electrode materials, shape, and the effect of spacing between electrodes on the stimulation, stiffness, and flexibility of electrode-carrying arrays are discussed. The use of sensors and the electrical, mechanical, and electrochemical properties of electrode arrays are examined. A large library of preferred electrodes is reviewed, and recent progress in electrode design parameters is analyzed. Finally, the limitations and challenges of the current technology are discussed along with a proposal of future directions in the field.
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Affiliation(s)
- Yavuz Nuri Ertas
- Department of Biomedical Engineering, Erciyes University, Kayseri 38039, Turkey; (D.O.); (S.N.K.)
- ERNAM—Nanotechnology Research and Application Center, Erciyes University, Kayseri 38039, Turkey
| | - Derya Ozpolat
- Department of Biomedical Engineering, Erciyes University, Kayseri 38039, Turkey; (D.O.); (S.N.K.)
- ERNAM—Nanotechnology Research and Application Center, Erciyes University, Kayseri 38039, Turkey
| | - Saime Nur Karasu
- Department of Biomedical Engineering, Erciyes University, Kayseri 38039, Turkey; (D.O.); (S.N.K.)
- ERNAM—Nanotechnology Research and Application Center, Erciyes University, Kayseri 38039, Turkey
| | - Nureddin Ashammakhi
- Institute for Quantitative Health Science and Engineering (IQ) and Department of Biomedical Engineering (BME), Michigan State University, East Lansing, MI 48824, USA
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27
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Matin-Mann F, Gao Z, Schwieger J, Ulbricht M, Domsta V, Senekowitsch S, Weitschies W, Seidlitz A, Doll K, Stiesch M, Lenarz T, Scheper V. Individualized, Additively Manufactured Drug-Releasing External Ear Canal Implant for Prevention of Postoperative Restenosis: Development, In Vitro Testing, and Proof of Concept in an Individual Curative Trial. Pharmaceutics 2022; 14:pharmaceutics14061242. [PMID: 35745813 PMCID: PMC9228097 DOI: 10.3390/pharmaceutics14061242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/16/2022] Open
Abstract
Postoperative restenosis in patients with external ear canal (EEC) atresia or stenosis is a common complication following canaloplasty. Our aim in this study was to explore the feasibility of using a three dimensionally (3D)-printed, patient-individualized, drug ((dexamethasone (DEX)), and ciprofloxacin (cipro))-releasing external ear canal implant (EECI) as a postoperative stent after canaloplasty. We designed and pre-clinically tested this novel implant for drug release (by high-performance liquid chromatography), biocompatibility (by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay), bio-efficacy (by the TNF-α (tumor necrosis factor-alpha)-reduction test (DEX) and inhibition zone test (for cipro)), and microbial contamination (formation of turbidity or sediments in culture medium). The EECI was implanted for the first time to one patient with a history of congenital EEC atresia and state after three canaloplasties due to EEC restenosis. The preclinical tests revealed no cytotoxic effect of the used materials; an antibacterial effect was verified against the bacteria Staphylococcus aureus and Pseudomonas aeruginosa, and the tested UV-irradiated EECI showed no microbiological contamination. Based on the test results, the combination of silicone with 1% DEX and 0.3% cipro was chosen to treat the patient. The EECI was implantable into the EEC; the postoperative follow-up visits revealed no otogenic symptoms or infections and the EECI was explanted three months postoperatively. Even at 12 months postoperatively, the EEC showed good epithelialization and patency. Here, we report the first ever clinical application of an individualized, drug-releasing, mechanically flexible implant and suggest that our novel EECI represents a safe and effective method for postoperatively stenting the reconstructed EEC.
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Affiliation(s)
- Farnaz Matin-Mann
- Department of Otorhinolaryngology, Head and Neck Surgery, Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany; (Z.G.); (J.S.); (T.L.); (V.S.)
- Correspondence: ; Tel.: +49-511-532-6565; Fax: +49-511-532-8001
| | - Ziwen Gao
- Department of Otorhinolaryngology, Head and Neck Surgery, Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany; (Z.G.); (J.S.); (T.L.); (V.S.)
- Cluster of Excellence”Hearing4all” EXC 1077/1, 30625 Hannover, Germany
| | - Jana Schwieger
- Department of Otorhinolaryngology, Head and Neck Surgery, Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany; (Z.G.); (J.S.); (T.L.); (V.S.)
- Cluster of Excellence”Hearing4all” EXC 1077/1, 30625 Hannover, Germany
| | - Martin Ulbricht
- Center of Drug Absorption and Transport, Department of Biopharmacy and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany; (M.U.); (V.D.); (S.S.); (W.W.); (A.S.)
| | - Vanessa Domsta
- Center of Drug Absorption and Transport, Department of Biopharmacy and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany; (M.U.); (V.D.); (S.S.); (W.W.); (A.S.)
| | - Stefan Senekowitsch
- Center of Drug Absorption and Transport, Department of Biopharmacy and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany; (M.U.); (V.D.); (S.S.); (W.W.); (A.S.)
| | - Werner Weitschies
- Center of Drug Absorption and Transport, Department of Biopharmacy and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany; (M.U.); (V.D.); (S.S.); (W.W.); (A.S.)
| | - Anne Seidlitz
- Center of Drug Absorption and Transport, Department of Biopharmacy and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany; (M.U.); (V.D.); (S.S.); (W.W.); (A.S.)
- Institute of Pharmaceutics and Biopharmaceutics, University of Duesseldorf, 40225 Dusseldorf, Germany
| | - Katharina Doll
- Clinic for Dental Prosthetics and Biomedical Materials Science, Hanover Medical School, 30625 Hannover, Germany; (K.D.); (M.S.)
| | - Meike Stiesch
- Clinic for Dental Prosthetics and Biomedical Materials Science, Hanover Medical School, 30625 Hannover, Germany; (K.D.); (M.S.)
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany; (Z.G.); (J.S.); (T.L.); (V.S.)
- Cluster of Excellence”Hearing4all” EXC 1077/1, 30625 Hannover, Germany
| | - Verena Scheper
- Department of Otorhinolaryngology, Head and Neck Surgery, Lower Saxony Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany; (Z.G.); (J.S.); (T.L.); (V.S.)
- Cluster of Excellence”Hearing4all” EXC 1077/1, 30625 Hannover, Germany
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28
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Biological Response Dynamics to Cochlear Implantation: Modeling and Modulating the Electrode–Tissue Interface. Ear Hear 2022; 43:1687-1697. [DOI: 10.1097/aud.0000000000001236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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29
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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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Dohr D, Wulf K, Grabow N, Mlynski R, Schraven SP. A PLLA Coating Does Not Affect the Insertion Pressure or Frictional Behavior of a CI Electrode Array at Higher Insertion Speeds. MATERIALS 2022; 15:ma15093049. [PMID: 35591381 PMCID: PMC9104964 DOI: 10.3390/ma15093049] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/14/2022] [Accepted: 04/14/2022] [Indexed: 01/27/2023]
Abstract
To prevent endocochlear insertion trauma, the development of drug delivery coatings in the field of CI electrodes has become an increasing focus of research. However, so far, the effect of a polymer coating of PLLA on the mechanical properties, such as the insertion pressure and friction of an electrode array, has not been investigated. In this study, the insertion pressure of a PLLA-coated, 31.5-mm long standard electrode array was examined during placement in a linear cochlear model. Additionally, the friction coefficients between a PLLA-coated electrode array and a tissue simulating the endocochlear lining were acquired. All data were obtained at different insertion speeds (0.1, 0.5, 1.0, 1.5, and 2.0 mm/s) and compared with those of an uncoated electrode array. It was shown that both the maximum insertion pressure generated in the linear model and the friction coefficient of the PLLA-coated electrode did not depend on the insertion speed. At higher insertion speeds above 1.0 mm/s, the insertion pressure (1.268 ± 0.032 mmHg) and the friction coefficient (0.40 ± 0.15) of the coated electrode array were similar to those of an uncoated array (1.252 ± 0.034 mmHg and 0.36 ± 0.15). The present study reveals that a PLLA coating on cochlear electrode arrays has a negligible effect on the electrode array insertion pressure and the friction when higher insertion speeds are used compared with an uncoated electrode array. Therefore, PLLA is a suitable material to be used as a coating for CI electrode arrays and can be considered for a potential drug delivery system.
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Affiliation(s)
- Dana Dohr
- Department of Otorhinolaryngology, Head and Neck Surgery “Otto Körner”, Rostock University Medical Center, 18057 Rostock, Germany; (R.M.); (S.P.S.)
- Correspondence: author
| | - Katharina Wulf
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock, Germany; (K.W.); (N.G.)
| | - Niels Grabow
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock, Germany; (K.W.); (N.G.)
| | - Robert Mlynski
- Department of Otorhinolaryngology, Head and Neck Surgery “Otto Körner”, Rostock University Medical Center, 18057 Rostock, Germany; (R.M.); (S.P.S.)
| | - Sebastian P. Schraven
- Department of Otorhinolaryngology, Head and Neck Surgery “Otto Körner”, Rostock University Medical Center, 18057 Rostock, Germany; (R.M.); (S.P.S.)
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Best Fit 3D Basilar Membrane Reconstruction to Routinely Assess the Scalar Position of the Electrode Array after Cochlear Implantation. J Clin Med 2022; 11:jcm11082075. [PMID: 35456169 PMCID: PMC9030636 DOI: 10.3390/jcm11082075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/03/2022] [Accepted: 04/05/2022] [Indexed: 12/04/2022] Open
Abstract
The scalar position of the electrode array is assumed to be associated with auditory performance after cochlear implantation. We propose a new method that can be routinely applied in clinical practice to assess the position of an electrode array. Ten basilar membrane templates were generated using micro-computed tomography (micro-CT), based on the dimensions of 100 cochleae. Five surgeons were blinded to determine the position of the electrode array in 30 cadaveric cochleae. The procedure consisted of selecting the appropriate template based on cochlear dimensions, merging the electrode array reconstruction with the template using four landmarks, determining the position of the array according to the template position, and comparing the results obtained to histology data. The time taken to analyze each implanted cochlea was approximately 12 min. We found that, according to histology, surgeons were in almost perfect agreement when determining an electrode translocated to the scala vestibuli with the perimodiolar MidScala array (Fleiss’ kappa (κ) = 0.82), and in moderate agreement when using the lateral wall EVO array (κ = 0.42). Our data indicate that an adapted basilar membrane template can be used as a rapid and reproducible method to assess the position of the electrode array after cochlear implantation.
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32
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Parys QA, Van Bulck P, Loos E, Verhaert N. Inner Ear Pharmacotherapy for Residual Hearing Preservation in Cochlear Implant Surgery: A Systematic Review. Biomolecules 2022; 12:biom12040529. [PMID: 35454118 PMCID: PMC9032072 DOI: 10.3390/biom12040529] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 02/05/2023] Open
Abstract
Cochlear implantation initiates an inflammatory cascade in which both acute insertion trauma and chronic foreign body reaction lead to intracochlear fibrosis and loss of residual hearing. Several strategies have been proposed to attenuate the local reactive process after implantation, including intracochlear drug delivery. The present study gives an overview of what is being investigated in the field of inner ear therapeutics and cochlear implant surgery. The aim is to evaluate its potential benefit in clinical practice. A systematic search was conducted in PubMed, Embase, and Cochrane Library databases identifying comparative prospective studies examining the effect of direct inner ear drug application on mechanical cochlear trauma. Both animal and human studies were considered and all studies were assessed for quality according to the validated risk of bias tools. Intracochlear administration of drugs is a feasible method to reduce the local inflammatory reaction following cochlear implantation. In animal studies, corticosteroid use had a significant effect on outcome measures including auditory brainstem response, impedance, and histological changes. This effect was, however, only durable with prolonged drug delivery. Significant differences in outcome were predominantly seen in studies where the cochlear damage was extensive. Six additional reports assessing non-steroidal agents were found. Overall, evidence of anti-inflammatory effects in humans is still scarce.
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Affiliation(s)
- Quentin-Alexandre Parys
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospitals Leuven, 3000 Leuven, Belgium; (Q.-A.P.); (P.V.B.); (E.L.)
| | - Pauline Van Bulck
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospitals Leuven, 3000 Leuven, Belgium; (Q.-A.P.); (P.V.B.); (E.L.)
| | - Elke Loos
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospitals Leuven, 3000 Leuven, Belgium; (Q.-A.P.); (P.V.B.); (E.L.)
- Department of Neurosciences, Research Group Experimental Oto-Rhino-Laryngology (ExpORL), KU Leuven, University of Leuven, 3000 Leuven, Belgium
| | - Nicolas Verhaert
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospitals Leuven, 3000 Leuven, Belgium; (Q.-A.P.); (P.V.B.); (E.L.)
- Department of Neurosciences, Research Group Experimental Oto-Rhino-Laryngology (ExpORL), KU Leuven, University of Leuven, 3000 Leuven, Belgium
- Correspondence:
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PLLA Coating of Active Implants for Dual Drug Release. Molecules 2022; 27:molecules27041417. [PMID: 35209205 PMCID: PMC8875406 DOI: 10.3390/molecules27041417] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 02/04/2023] Open
Abstract
Cochlear implants, like other active implants, rely on precise and effective electrical stimulation of the target tissue but become encapsulated by different amounts of fibrous tissue. The current study aimed at the development of a dual drug release from a PLLA coating and from the bulk material to address short-term and long-lasting release of anti-inflammatory drugs. Inner-ear cytocompatibility of drugs was studied in vitro. A PLLA coating (containing diclofenac) of medical-grade silicone (containing 5% dexamethasone) was developed and release profiles were determined. The influence of different coating thicknesses (2.5, 5 and 10 µm) and loadings (10% and 20% diclofenac) on impedances of electrical contacts were measured with and without pulsatile electrical stimulation. Diclofenac can be applied to the inner ear at concentrations of or below 4 × 10−5 mol/L. Release of dexamethasone from the silicone is diminished by surface coating but not blocked. Addition of 20% diclofenac enhances the dexamethasone release again. All PLLA coatings serve as insulator. This can be overcome by using removable masking on the contacts during the coating process. Dual drug release with different kinetics can be realized by adding drug-loaded coatings to drug-loaded silicone arrays without compromising electrical stimulation.
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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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Dexamethasone for Inner Ear Therapy: Biocompatibility and Bio-Efficacy of Different Dexamethasone Formulations In Vitro. Biomolecules 2021; 11:biom11121896. [PMID: 34944539 PMCID: PMC8699596 DOI: 10.3390/biom11121896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/10/2021] [Accepted: 12/14/2021] [Indexed: 01/27/2023] Open
Abstract
Dexamethasone is widely used in preclinical studies and clinical trials to treat inner ear disorders. The results of those studies vary widely, maybe due to the different dexamethasone formulations used. Laboratory (lab) and medical grade (med) dexamethasone (DEX, C22H29FO5) and dexamethasone dihydrogen phosphate-disodium (DPS, C22H28FNa2O8P) were investigated for biocompatibility and bio-efficacy in vitro. The biocompatibility of each dexamethasone formulation in concentrations from 0.03 to 10,000 µM was evaluated using an MTT assay. The concentrations resulting in the highest cell viability were selected to perform a bio-efficiency test using a TNFα-reduction assay. All dexamethasone formulations up to 900 µM are biocompatible in vitro. DPS-lab becomes toxic at 1000 µM and DPS-med at 2000 µM, while DEX-lab and DEX-med become toxic at 4000 µM. Bio-efficacy was evaluated for DEX-lab and DPS-med at 300 µM, for DEX-med at 60 µM, and DPS-lab at 150 µM, resulting in significantly reduced expression of TNFα, with DPS-lab having the highest effect. Different dexamethasone formulations need to be applied in different concentration ranges to be biocompatible. The concentration to be applied in future studies should carefully be chosen based on the respective dexamethasone form, application route and duration to ensure biocompatibility and bio-efficacy.
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36
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Saoji AA, Graham M, Stein A, Koka K. Analysis of electrode impedance and its subcomponents for lateral wall, mid-scala, and perimodiolar electrodes in cochlear implants. Cochlear Implants Int 2021; 23:87-94. [PMID: 34895078 DOI: 10.1080/14670100.2021.2000734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Electrode impedances play an important role in cochlear implant patient management. During clinical visits, electrode impedances are calculated from a single point voltage waveform. In the present study, multipoint electrode impedance analysis was performed to study electrode impedance and its subcomponents in patients with three different types of cochlear implant electrode arrays. DESIGN Voltage waveforms were measured at six different time points during the cathodic phase of a biphasic pulse in forty-seven cochlear implant patients with perimodiolar, mid-scala, or lateral wall electrode arrays. Multipoint electrode impedances were used to determine access resistance and polarization impedance. RESULTS Access resistance of approximately 5 kΩ was calculated across the three different electrode arrays. Mid-scala electrodes showed a smaller increase in impedances as a function of pulse duration compared to the other electrodes. Patients with lower impedances showed higher capacitance and lower resistance, suggesting that differences in electrochemical reaction at the electrodes' surface can influence impedances in cochlear implants. CONCLUSIONS Analysis of cochlear implant electrode impedances and their subcomponents provides valuable information about resistance to the flow of current between stimulating and return electrodes, and build an understanding of the contribution of electrochemical processes used to deliver electrical stimulation to the auditory nerve.
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Affiliation(s)
- Aniket A Saoji
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN, USA
| | - Madison Graham
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN, USA
| | - Amy Stein
- Research and Technology, Advanced Bionics, Valencia, CA, USA
| | - Kanthaiah Koka
- Research and Technology, Advanced Bionics, Valencia, CA, USA
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37
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Tarabichi O, Jensen M, Hansen MR. Advances in hearing preservation in cochlear implant surgery. Curr Opin Otolaryngol Head Neck Surg 2021; 29:385-390. [PMID: 34354014 PMCID: PMC9002354 DOI: 10.1097/moo.0000000000000742] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Advancements in cochlear implant surgical approaches and electrode designs have enabled preservation of residual acoustic hearing. Preservation of low-frequency hearing allows cochlear implant users to benefit from electroacoustic stimulation, which improves performance in complex listening situations, such as music appreciation and speech understanding in noise. Despite the relative high rates of success of hearing preservation, postoperative acoustic hearing outcomes remain unpredictable. RECENT FINDINGS Thin, flexible, lateral wall arrays are preferred for hearing preservation. Both shortened and thin, lateral wall arrays have shown success with hearing preservation and the optimal implant choice is an issue of ongoing investigation. Electrocochleography can monitor cochlear function during and after insertion of the electrode array. The pathophysiology of hearing loss acutely after cochlear implant may differ from that involved in delayed hearing loss following cochlear implant. Emerging innovations may reduce cochlear trauma and improve hearing preservation. SUMMARY Hearing preservation is possible using soft surgical techniques and electrode arrays designed to minimize cochlear trauma; however, a subset of patients suffer from partial to total loss of acoustic hearing months to years following surgery despite evidence of residual apical hair cell function. Early investigations in robotic-assisted insertion and dexamethasone-eluting implants show promise.
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Affiliation(s)
- Osama Tarabichi
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, IA
| | - Megan Jensen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, IA
| | - Marlan R. Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, IA
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38
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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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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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Luo Y, Chen A, Xu M, Chen D, Tang J, Ma D, Zhang H. Preparation, characterization, and in vitro/ vivo evaluation of dexamethasone/poly(ε-caprolactone)-based electrode coatings for cochlear implants. Drug Deliv 2021; 28:1673-1684. [PMID: 34347538 PMCID: PMC8344245 DOI: 10.1080/10717544.2021.1960927] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
With dexamethasone as the model drug and polycaprolactone (PCL) as the carrier material, a drug delivery coating for cochlear electrodes was prepared, to control cochlear fibrosis caused by cochlear implantation. A dexamethasone/poly (ε-caprolactone)-based electrode coating was prepared using the impregnation coating method. Preparation parameters were optimized, yielding 1 impregnation instance, impregnation time of 10 s, and PCL concentration of 10%. The coating was characterized in vitro using scanning electron microscopy, a universal machine, high-performance liquid chromatography, and CCK-8. The surface was porous and uniformly thick (average thickness, 48.67 µm)—with good flexibility, long-term slow drug release, and optimal drug concentration—and was biologically safe. The experimental results show that PCL is an ideal controlled-release material for dexamethasone as a drug carrier coating for cochlear implants.
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Affiliation(s)
- Yanjing Luo
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,Hearing Research Center, Southern Medical University, Guangzhou, China
| | - Anning Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,Hearing Research Center, Southern Medical University, Guangzhou, China
| | - Muqing Xu
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,Hearing Research Center, Southern Medical University, Guangzhou, China
| | - Dongxiu Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,Hearing Research Center, Southern Medical University, Guangzhou, China
| | - Jie Tang
- Hearing Research Center, Southern Medical University, Guangzhou, China.,Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China
| | - Dong Ma
- Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou, China
| | - Hongzheng Zhang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,Hearing Research Center, Southern Medical University, Guangzhou, China
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41
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Jensen MJ, Peel A, Horne R, Chamberlain J, Xu L, Hansen MR, Guymon CA. Antifouling and Mechanical Properties of Photografted Zwitterionic Hydrogel Thin-Film Coatings Depend on the Cross-Link Density. ACS Biomater Sci Eng 2021; 7:4494-4502. [PMID: 34347419 PMCID: PMC8441969 DOI: 10.1021/acsbiomaterials.1c00852] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Zwitterionic polymer networks have shown promise in reducing the short- and long-term inflammatory foreign body response to implanted biomaterials by combining the antifouling properties of zwitterionic polymers with the mechanical stability provided by cross-linking. Cross-link density directly modulates mechanical properties (i.e., swelling behavior, resistance to stress and strain, and lubricity) but theoretically could reduce desirable biological properties (i.e., antifouling) of zwitterionic materials. This work examined the effect of varying poly(ethylene glycol) dimethacrylate cross-linker concentration on protein adsorption, cell adhesion, equilibrium swelling, compressive modulus, and lubricity of zwitterionic thin films. Furthermore, this work aimed to determine the appropriate balance among each of these mechanical and biologic properties to produce thin films that are strong, durable, and lubricious, yet also able to resist biofouling. The results demonstrated nearly a 20-fold reduction in fibrinogen adsorption on zwitterionic thin films photografted on polydimethylsiloxane (PDMS) across a wide range of cross-link densities. Interestingly, either at high or low cross-link densities, increased levels of protein adsorption were observed. In addition to fibrinogen, macrophage and fibroblast cell adhesion was reduced significantly on zwitterionic thin films, with a large range of cross-link densities, resulting in low cell counts. The macrophage count was reduced by 30-fold, while the fibroblast count was reduced nearly 10-fold on grafted zwitterionic films relative to uncoated films. Increasing degrees of cell adhesion were noted as the cross-linker concentration exceeded 50%. As expected, increased cross-link density resulted in a reduced swelling but greater compressive modulus. Notably, the coefficient of friction was dramatically reduced for zwitterionic thin films compared to uncoated PDMS across a broad range of cross-link densities, an attractive property for insertional implants. This work identified a broad range of cross-link densities that provide desirable antifouling effects while also maintaining the mechanical functionality of the thin films.
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Affiliation(s)
- Megan J Jensen
- Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City, Iowa 52242, United States
| | - Adreann Peel
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Ryan Horne
- Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Jamison Chamberlain
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Linjing Xu
- Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City, Iowa 52242, United States
| | - Marlan R Hansen
- Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Neurosurgery, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242, United States
| | - C Allan Guymon
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
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Abstract
Cochlear implant surgery is a successful procedure for auditory rehabilitation of patients with severe to profound hearing loss. However, cochlear implantation may lead to damage to the inner ear, which decreases residual hearing and alters vestibular function. It is now of increasing interest to preserve residual hearing during this surgery because this is related to better speech, music perception, and hearing in complex listening environments. Thus, different efforts have been tried to reduce cochlear implantation-related injury, including periprocedural glucocorticoids because of their anti-inflammatory properties. Different routes of administration have been tried to deliver glucocorticoids. However, several drawbacks still remain, including their systemic side effects, unknown pharmacokinetic profiles, and complex delivery methods. In the present review, we discuss the role of periprocedural glucocorticoid therapy to decrease cochlear implantation-related injury, thus preserving inner ear function after surgery. Moreover, we highlight the pharmacokinetic evidence and clinical outcomes which would sustain further interventions.
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Li J, Wu Y, Zhuo J, Wang Z. Modeling and simulation of cochlear perimodiolar electrode based on composite spring-mass model. Comput Methods Biomech Biomed Engin 2021; 25:290-297. [PMID: 34263671 DOI: 10.1080/10255842.2021.1950145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This paper proposes, a method for the physical modeling of the perimodiolar electrode, particularly for the process of recovering its preset shape with the guide wire drawn out, based on the composite spring-mass model by employing the virtual-volumetric spring inspired from the traditional spring-mass model. Simulation experiments of modeling and virtual insertion of perimodiolar electrode were carried out. The results indicated that the mean and standard deviation of the difference between the local deformation angles of the simulated and measured sets of mass points, (1, 2, 3), (2, 3, 4), …, (13, 14, 15), were 6.34° and 5.98°, respectively. Additionally, the physical model of the perimodiolar electrode can reflect the overall morphological changes of the real perimodiolar electrode.
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Affiliation(s)
- Jianjun Li
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou, China
| | - Yue Wu
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou, China
| | - Jianye Zhuo
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou, China
| | - Zuo Wang
- College of Artificial Intelligence and Innovation, Ma'anshan University, Ma'anshan, China
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Kather M, Koitzsch S, Breit B, Plontke S, Kammerer B, Liebau A. Metabolic reprogramming of inner ear cell line HEI-OC1 after dexamethasone application. Metabolomics 2021; 17:52. [PMID: 34028607 PMCID: PMC8144088 DOI: 10.1007/s11306-021-01799-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/29/2021] [Indexed: 12/26/2022]
Abstract
INTRODUCTION One approach to dampen the inflammatory reactions resulting from implantation surgery of cochlear implant hearing aids is to embed dexamethasone into the matrix of the electrode carrier. Possible side effects for sensory cells in the inner ear on the metabolomics have not yet been evaluated. OBJECTIVE We examined changes in the metabolome of the HEI-OC1 cell line after dexamethasone incubation as a cell model of sensory cells of the inner ear. RESULTS AND CONCLUSION Untargeted GC-MS-profiling of metabolic alterations after dexamethasone treatment showed that dexamethasone had antithetical effects on the metabolic signature of the cells depending on growth conditions. The differentiated state of HEI-OC1 cells is better suited for elucidating metabolic changes induced by external factors. Dexamethasone treatment of differentiated cells led to an increase in intracellular amino acids and enhanced glucose uptake and β-oxidation in the cells. Increased availability of precursors for glycolysis and ATP production by β-oxidation stabilizes the energy supply in the cells, which could be assumed to be beneficial in coping with cellular stress. We found no negative effects of dexamethasone on the metabolic level, and changes may even prepare sensory cells to better overcome cellular stress following implantation surgery.
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Affiliation(s)
- Michel Kather
- Centre for Integrative Biological Signalling Studies CISA, University of Freiburg, Habsburger Straße 49, 79104, Freiburg, Germany
- Hermann Staudinger Graduate School, University of Freiburg, Hebelstr. 27, 79104, Freiburg, Germany
- Institute of Organic Chemistry, University of Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Sabine Koitzsch
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Straße 40, 06120, Halle (Saale), Germany
| | - Bernhard Breit
- Institute of Organic Chemistry, University of Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Stefan Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Straße 40, 06120, Halle (Saale), Germany
| | - Bernd Kammerer
- Centre for Integrative Biological Signalling Studies CISA, University of Freiburg, Habsburger Straße 49, 79104, Freiburg, Germany.
- Institute of Organic Chemistry, University of Freiburg, Albertstraße 21, 79104, Freiburg, Germany.
- Centre for Biological Signalling Studies BIOSS, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- Center for Biosystems Analysis, ZBSA, University of Freiburg, Habsburgerstr. 49, 79104, Freiburg, Germany.
| | - Arne Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Straße 40, 06120, Halle (Saale), Germany.
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Hough K, Sanderson A, Grasmeder M, Mitchell T, Verschuur CA, Newman TA. Inflammation at the Tissue-Electrode Interface in a Case of Rapid Deterioration in Hearing Performance Leading to Explant After Cochlear Implantation. Otol Neurotol 2021; 42:e445-e450. [PMID: 33710995 DOI: 10.1097/mao.0000000000003014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The reasons for soft failure after cochlear implantation require investigation. This study proposes a method to study and characterize the tissue response to the array in a case of soft failure in a person undergoing reimplantation. CASE The woman in her 50s, with an underlying autoimmune condition, received a cochlear implant using hearing preservation technique after developing profound hearing loss more than 2 kHz with a moderate loss of less than 500 Hz over a 10-year period. The case was identified as a soft failure due to deteriorating performance, discomfort, and migration over the 10 months after implantation. Impedance telemetry, speech perception measures, and audiometric thresholds are described. At explantation there was evidence of fibrosis. INTERVENTIONS To use histology and immunohistochemistry to determine the cellular response of the tissue associated with the electrode array at time of explantation. MAIN OUTCOME MEASURES Identification of the cell types, regional variations, and inflammatory marker expression in the fibrotic tissue associated with the array. RESULTS Neutrophils and eosinophils were identified, along with a variable pattern of collagen deposition. CD68 and CD163-positive macrophages and T cells were variably distributed through the tissue and interleukin-1 beta and vascular endothelial growth factor receptor-2 expression was identified. CONCLUSIONS The expression profile is evidence of active inflammation in the tissue despite the time since implantation. This study is the first to characterize the tissue response to the array in a person undergoing reimplantation, and who can be followed to determine the individual response to arrays. It establishes that the investigation of explanted devices after soft-failure is feasible.
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Affiliation(s)
- Kate Hough
- Faculty of Engineering and Physical Sciences
| | | | - Mary Grasmeder
- Faculty of Engineering and Physical Sciences, Auditory Implant Centre
| | - Tim Mitchell
- Faculty of Engineering and Physical Sciences, Auditory Implant Centre
| | - Carl A Verschuur
- Faculty of Engineering and Physical Sciences, Auditory Implant Centre
| | - Tracey A Newman
- Clinical and Experimental Sciences, Faculty of Medicine, Institute for Life Sciences, University of Southampton, Southampton, UK
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Gao J, Yi H. Molecular mechanisms and roles of inflammatory responses on low-frequency residual hearing after cochlear implantation. J Otol 2021; 17:54-58. [PMID: 35140760 PMCID: PMC8811416 DOI: 10.1016/j.joto.2021.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/25/2021] [Accepted: 03/02/2021] [Indexed: 01/28/2023] Open
Abstract
Preservation of low-frequency residual hearing is very important for combined electro-acoustic stimulation after cochlear implantation. However, in clinical practice, loss of low-frequency residual hearing often occurs after cochlear implantation and its mechanisms remain unclear. Factors affecting low-frequency residual hearing after cochlear implantation are one of the hot spots in current research. Inflammation induced by injury associated with cochlear implantation is deemed to be significant, as it may give rise to low-frequency residual hearing loss by interfering with the blood labyrinth barrier and neural synapses. Pathological changes along the pathway for low-frequency auditory signals transmission may include latent factors such as damage to neuroepithelial structures, synapses, stria vascularis and other ultrastructures. In this review, current research on mechanisms of low-frequency residual hearing loss after cochlear implantation and possible roles of inflammatory responses are summarized.
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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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48
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O'Leary SJ, Choi J, Brady K, Matthews S, Ozdowska KB, Payne M, McLean T, Rousset A, Lo J, Creber N, Tari S, Dowell R, Briggs R. Systemic methylprednisolone for hearing preservation during cochlear implant surgery: A double blinded placebo-controlled trial. Hear Res 2021; 404:108224. [PMID: 33774594 DOI: 10.1016/j.heares.2021.108224] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 01/13/2023]
Abstract
AIM To assess whether a single, peri-operative, high dose of methylprednisolone can improve the preservation of residual acoustic hearing following cochlear implantation (CI). METHODS This was a double blinded placebo-controlled trial, performed in a tertiary academic centre. The hypothesis was that methylprednisolone would improve the preservation of hearing, and lower electrode impedances. Adult patients (18-85 years) with hearing at 85 dB or better at 500 Hz in the ear to be implanted were randomly allocated to either treatment (methylprednisolone, 1g administered intravenously upon induction of anaesthesia) or control (normal saline infusion). As per standard clinical practice, all patients received a routine dose of dexamethasone (8 mg intravenously) on induction of anaesthesia. Implantation was undertaken with a slim and flexible lateral wall electrode via the round window. Surgical technique was routine, with adherence to soft surgical principles. The primary outcome was hearing preservation within 20 dB at 500 Hz, 12 months following cochlear implantation. Secondary outcomes included hearing preservation at 6 weeks and 3 months, monopolar electrode impedance, and Consonant-Vowel-Consonant (CVC) Phoneme scores at 3 and 12 months after surgery. RESULTS Forty-five patients were enrolled into the control group and 48 patients received the steroid. The number of patients achieving hearing preservation at 12 months did not differ significantly between those receiving methylprednisolone treatment and the controls. There were no differences in hearing preservation at any frequency at either 6 weeks or 3 months after implantation. Neither CVC phoneme scores nor electrode impedances differed between the groups. CONCLUSIONS This paper demonstrates that high-dose local steroid injection at surgery was not effective in preventing a loss of residual hearing, improving speech perception, or lowering electrode impedances. The findings were contrary to the experimental literature, and emerging clinical evidence that steroid elution from implant electrodes influences cochlear biology in humans. We found no evidence to support the widely-held practice of administering intravenous steroids in the perioperative period, in an attempt to preserve residual hearing.
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Affiliation(s)
- Stephen J O'Leary
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia; Cochlear Implant Clinic, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, Melbourne East 3002, Australia.
| | - June Choi
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia; Department of Otorhinolaryngology - Head & Neck Surgery, Ansan Hospital, College of Medicine, Korea University, 123, Jeokgeum-ro (Street), Gojan-dong, Danwon-gu, Ansan-si, Gyeonggi-do 15355, Republic of Korea
| | - Karina Brady
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Sheila Matthews
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Katie Boncza Ozdowska
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Matthew Payne
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Tim McLean
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Alex Rousset
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Jonathon Lo
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Nathan Creber
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Sylvia Tari
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia
| | - Richard Dowell
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia; Department of Audiology and Speech Sciences, University of Melbourne, 550 Swanston St, Carlton 3053, Australia
| | - Robert Briggs
- Department of Surgery - Otolaryngology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St RVEEH, Melbourne East 3002,Victoria, Australia; Cochlear Implant Clinic, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, Melbourne East 3002, Australia
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49
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Perin P, Marino F, Varela-Nieto I, Szczepek AJ. Editorial: Neuroimmunology of the Inner Ear. Front Neurol 2021; 12:635359. [PMID: 33633679 PMCID: PMC7899967 DOI: 10.3389/fneur.2021.635359] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/07/2021] [Indexed: 12/20/2022] Open
Affiliation(s)
- Paola Perin
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | - Franca Marino
- Center of Research in Medical Pharmacology University of Insubria, Varese, Italy
| | - Isabel Varela-Nieto
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Rare Diseases Networking Biomedical Research Centre, Centro de Investigación Biomédica en Red, Carlos III Institute of Health, Madrid, Spain.,La Paz Hospital Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Agnieszka J Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Faculty of Medicine and Health Sciences, University of Zielona Gora, Zielona Gora, Poland
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50
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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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