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Wang L, Zhang R, Jiang L, Gao S, Wu J, Jiao Y. Biomaterials as a new option for treating sensorineural hearing loss. Biomater Sci 2024; 12:4006-4023. [PMID: 38979939 DOI: 10.1039/d4bm00518j] [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: 07/10/2024]
Abstract
Sensorineural hearing loss (SNHL) usually involves damage to complex auditory pathways such as inner ear cells and auditory nerves. The highly intricate and nuanced characteristics of these cells render their repair and regeneration extremely challenging, making it difficult to restore hearing to normal levels once it has been compromised. The effectiveness of traditional drugs is so minimal that they provide little help with the treatment. Fortunately, extensive experiments have demonstrated that combining biomaterials with conventional techniques significantly enhances drug effectiveness. This article reviews the research progress of biomaterials in protecting hair cells and the auditory nerve, repairing genes related to hearing, and developing artificial cochlear materials. By organizing the knowledge presented in this article, perhaps new insights can be provided for the clinical management of SNHL.
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Affiliation(s)
- Liwen Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Guangzhou Twelfth People's Hospital (The Affiliated Twelfth People's Hospital of Guangzhou Medical University), Guangzhou 510620, China
- Institute of Otorhinolaryngology, Head and Neck Surgery, Guangzhou Medical University, Guangzhou 510620, China.
| | - Ruhe Zhang
- Department of Hematology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China
| | - Linlan Jiang
- Department of Otorhinolaryngology Head and Neck Surgery, Guangzhou Twelfth People's Hospital (The Affiliated Twelfth People's Hospital of Guangzhou Medical University), Guangzhou 510620, China
- Institute of Otorhinolaryngology, Head and Neck Surgery, Guangzhou Medical University, Guangzhou 510620, China.
| | - Shuyi Gao
- Department of Otorhinolaryngology Head and Neck Surgery, Guangzhou Twelfth People's Hospital (The Affiliated Twelfth People's Hospital of Guangzhou Medical University), Guangzhou 510620, China
- Institute of Otorhinolaryngology, Head and Neck Surgery, Guangzhou Medical University, Guangzhou 510620, China.
| | - Jun Wu
- Institute of Otorhinolaryngology, Head and Neck Surgery, Guangzhou Medical University, Guangzhou 510620, China.
- Bioscience and Biomedical Engineering Thrust, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou 511400, China.
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yuenong Jiao
- Department of Otorhinolaryngology Head and Neck Surgery, Guangzhou Twelfth People's Hospital (The Affiliated Twelfth People's Hospital of Guangzhou Medical University), Guangzhou 510620, China
- Institute of Otorhinolaryngology, Head and Neck Surgery, Guangzhou Medical University, Guangzhou 510620, China.
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Goyal MM, Shen SA, Lehar M, Martinez A, Hiel H, Wang C, Liu Y, Wang C, Sun DQ. A Benchtop Round Window Model for Studying Magnetic Nanoparticle Transport to the Inner Ear. Laryngoscope 2024; 134:3355-3362. [PMID: 38379206 DOI: 10.1002/lary.31345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/09/2024] [Accepted: 01/30/2024] [Indexed: 02/22/2024]
Abstract
INTRODUCTION The round window membrane (RWM) presents a significant barrier to the local application of therapeutics to the inner ear. We demonstrate a benchtop preclinical RWM model and evaluate superparamagnetic iron oxide nanoparticles (SPIONs) as vehicles for magnetically assisted drug delivery. METHODS Guinea pig RWM explants were inset into a 3D-printed dual chamber benchtop device. Custom-synthesized 7-nm iron core nanoparticles were modified with different polyethylene glycol chains to yield two sizes of SPIONs (NP-PEG600 and NP-PEG3000) and applied to the benchtop model with and without a magnetic field. Histologic analysis of the RWM was performed using transmission electron microscopy (TEM) and confocal microscopy. RESULTS Over a 4-h period, 19.5 ± 1.9% of NP-PEG3000 and 14.6 ± 1.9% of NP-PEG600 were transported across the guinea pig RWM. The overall transport increased by 1.45× to 28.4 ± 5.8% and 21.0 ± 2.0%, respectively, when a magnetic field was applied. Paraformaldehyde fixation of the RWM decreased transport significantly (NP-PEG3000: 7.6 ± 1.5%; NP-PEG600: 7.0 ± 1.6%). Confocal and electron microscopy analysis demonstrated nanoparticle localization throughout all cellular layers and layer-specific transport characteristics within RWM. CONCLUSION The guinea pig RWM explant benchtop model allows for targeted and practical investigations of transmembrane transport in the development of nanoparticle drug delivery vehicles. The presence of a magnetic field increases SPION delivery by 45%-50% in a nanoparticle size- and cellular layer-dependent manner. LEVEL OF EVIDENCE NA Laryngoscope, 134:3355-3362, 2024.
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Affiliation(s)
- Mukund M Goyal
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sarek A Shen
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mohamed Lehar
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Angela Martinez
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hakim Hiel
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Canhui Wang
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yulin Liu
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Chao Wang
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Daniel Q Sun
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Falconieri A, Folino P, Da Palmata L, Raffa V. Nano-pulling stimulates axon regeneration in dorsal root ganglia by inducing stabilization of axonal microtubules and activation of local translation. Front Mol Neurosci 2024; 17:1340958. [PMID: 38633213 PMCID: PMC11022966 DOI: 10.3389/fnmol.2024.1340958] [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: 11/19/2023] [Accepted: 03/11/2024] [Indexed: 04/19/2024] Open
Abstract
Introduction Axonal plasticity is strongly related to neuronal development as well as regeneration. It was recently demonstrated that active mechanical tension, intended as an extrinsic factor, is a valid contribution to the modulation of axonal plasticity. Methods In previous publications, our team validated a the "nano-pulling" method used to apply mechanical forces to developing axons of isolated primary neurons using magnetic nanoparticles (MNP) actuated by static magnetic fields. This method was found to promote axon growth and synaptic maturation. Here, we explore the use of nano-pulling as an extrinsic factor to promote axon regeneration in a neuronal tissue explant. Results Whole dorsal root ganglia (DRG) were thus dissected from a mouse spinal cord, incubated with MNPs, and then stretched. We found that particles were able to penetrate the ganglion and thus become localised both in the somas and in sprouting axons. Our results highlight that nano-pulling doubles the regeneration rate, and this is accompanied by an increase in the arborizing capacity of axons, an accumulation of cellular organelles related to mass addition (endoplasmic reticulum and mitochondria) and pre-synaptic proteins with respect to spontaneous regeneration. In line with the previous results on isolated hippocampal neurons, we observed that this process is coupled to an increase in the density of stable microtubules and activation of local translation. Discussion Our data demonstrate that nano-pulling enhances axon regeneration in whole spinal ganglia exposed to MNPs and external magnetic fields. These preliminary data represent an encouraging starting point for proposing nano-pulling as a biophysical tool for the design of novel therapies based on the use of force as an extrinsic factor for promoting nerve regeneration.
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Dąbkowska M, Stukan I, Kosiorowska A, Szatanik A, Łuczkowska K, Machalińska A, Machaliński B. In vitro and in vivo characterization of human serum albumin-based PEGylated nanoparticles for BDNF and NT3 codelivery. Int J Biol Macromol 2024; 265:130726. [PMID: 38490392 DOI: 10.1016/j.ijbiomac.2024.130726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 02/28/2024] [Accepted: 03/06/2024] [Indexed: 03/17/2024]
Abstract
The utilization of neurotrophins in medicine shows significant potential for addressing neurodegenerative conditions, such as age-related macular degeneration (AMD). However, the therapeutic use of neurotrophins has been restricted due to their short half-life. Here, we aimed to synthesize PEGylated nanoparticles based on electrostatic-driven interactions between human serum albumin (HSA), a carrier for adsorption; neurotrophin-3 (NT3); and brain-derived neurotrophic factor (BDNF). Electrophoretic (ELS) and multi-angle dynamic light scattering (MADLS) revealed that the PEGylated HSA-NT3-BDNF nanoparticles ranged from 10 to 430 nm in diameter and exhibited a low polydispersity index (<0.4) and a zeta potential of -8 mV. Based on microscale thermophoresis (MST), the estimated dissociation constant (Kd) from the HSA molecule of BDNF was 1.6 μM, and the Kd of NT3 was 732 μM. The nanoparticles were nontoxic toward ARPE-19 and L-929 cells in vitro and efficiently delivered BDNF and NT3. Based on the biodistribution of neurotrophins after intravitreal injection into BALB/c mice, both nanoparticles were gradually released in the mouse vitreous body within 28 days. PEGylated HSA-NT3-BDNF nanoparticles stabilize neurotrophins and maintain this characteristic in vivo. Thus, given the simplicity of the system, the nanoparticles may enhance the treatment of a variety of neurological disorders in the future.
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Affiliation(s)
- Maria Dąbkowska
- Independent Laboratory of Pharmacokinetic and Clinical Pharmacy, Rybacka 1, 71-899 Szczecin, Poland.
| | - Iga Stukan
- Department of General Pathology, Pomeranian Medical University, Rybacka 1, 70-111 Szczecin, Poland
| | - Alicja Kosiorowska
- Independent Laboratory of Pharmacokinetic and Clinical Pharmacy, Rybacka 1, 71-899 Szczecin, Poland; Department of General Pathology, Pomeranian Medical University, Rybacka 1, 70-111 Szczecin, Poland
| | - Alicja Szatanik
- Independent Laboratory of Pharmacokinetic and Clinical Pharmacy, Rybacka 1, 71-899 Szczecin, Poland
| | - Karolina Łuczkowska
- Department of General Pathology, Pomeranian Medical University, Rybacka 1, 70-111 Szczecin, Poland
| | - Anna Machalińska
- First Department of Ophthalmology, Pomeranian Medical University, 70-111 Szczecin, Poland
| | - Bogusław Machaliński
- Department of General Pathology, Pomeranian Medical University, Rybacka 1, 70-111 Szczecin, Poland
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Behrends W, Ahrens D, Bankstahl JP, Esser KH, Paasche G, Lenarz T, Scheper V. Refinement of systemic guinea pig deafening in hearing research: Sensorineural hearing loss induced by co-administration of kanamycin and furosemide via the leg veins. Lab Anim 2023; 57:631-641. [PMID: 37070340 DOI: 10.1177/00236772231167679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Auditory disabilities have a large impact on the human population worldwide. Research into understanding and treating hearing disabilities has increased significantly in recent years. One of the most relevant animal species in this context is the guinea pig, which has to be deafened to study several of the hearing pathologies and develop novel therapies. Applying kanamycin subcutaneously and furosemide intravenously is a long-established method in hearing research, leading to permanent hearing loss without surgical intervention at the ear. The intravenous application of furosemide requires invasive surgery in the cervical area of the animals to expose the jugular vein, since a relatively large volume (1 ml per 500 g body weight) must be injected over a period of about 2.5 min. We have established a gentler alternative by applying the furosemide by puncture of the leg veins. For this, custom-made cannula-needle devices were built to allow the vein puncture and subsequent slow injection of the furosemide. This approach was tested in 11 guinea pigs through the foreleg via the cephalic antebrachial vein and through the hind leg via the saphenous vein. Frequency-specific hearing thresholds were measured before and after the procedure to verify normal hearing and successful deafening, respectively. The novel approach of systemic deafening was successfully implemented in 10 out of 11 animals. The Vena saphena was best suited to the application. Since the animals' condition, post leg vein application, was better in comparison to animals deafened by exposure of the Vena jugularis, the postulated refinement that reduced animal stress was deemed successful.
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Affiliation(s)
- Wiebke Behrends
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Auditory Neuroethology and Neurobiology, Institute of Zoology, University of Veterinary Medicine Hannover Foundation, Germany
| | - Daniel Ahrens
- Department of Nuclear Medicine, Hannover Medical School, Germany
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Germany
| | - Karl-Heinz Esser
- Auditory Neuroethology and Neurobiology, Institute of Zoology, University of Veterinary Medicine Hannover Foundation, Germany
| | - Gerrit Paasche
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Hearing4all Cluster of Excellence, Hannover Medical School, Germany
| | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Hearing4all Cluster of Excellence, Hannover Medical School, Germany
| | - Verena Scheper
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Hearing4all Cluster of Excellence, Hannover Medical School, Germany
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Vink HA, Ramekers D, Foster AC, Versnel H. The efficacy of a TrkB monoclonal antibody agonist in preserving the auditory nerve in deafened guinea pigs. Hear Res 2023; 439:108895. [PMID: 37837701 DOI: 10.1016/j.heares.2023.108895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/31/2023] [Accepted: 10/02/2023] [Indexed: 10/16/2023]
Abstract
The auditory nerve typically degenerates following loss of cochlear hair cells or synapses. In the case of hair cell loss neural degeneration hinders restoration of hearing through a cochlear implant, and in the case of synaptopathy suprathreshold hearing is affected, potentially degrading speech perception in noise. It has been established that neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) can mitigate auditory nerve degeneration. Several potential BDNF mimetics have also been investigated for neurotrophic effects in the cochlea. A recent in vitro study showed favorable effects of M3, a TrkB monoclonal antibody agonist, when compared with BDNF. In the present study we set out to examine the effect of M3 on auditory nerve preservation in vivo. Thirty-one guinea pigs were bilaterally deafened, and unilaterally treated with a single 3-µl dose of 7 mg/ml, 0.7 mg/ml M3 or vehicle-only by means of a small gelatin sponge two weeks later. During the experiment and analyses the experimenters were blinded to the three treatment groups. Four weeks after treatment, we assessed the treatment effect (1) histologically, by quantifying survival of SGCs and their peripheral processes (PPs); and (2) electrophysiologically, with two different paradigms of electrically evoked compound action potential (eCAP) recordings shown to be indicative of neural health: single-pulse stimulation with varying inter-phase gap (IPG), and pulse-train stimulation with varying inter-pulse interval. We observed a consistent and significant preservative effect of M3 on SGC survival in the lower basal turn (approximately 40% more survival than in the untreated contralateral cochlea), but also in the upper middle and lower apical turn of the cochlea. This effect was similar for the two treatment groups. Survival of PPs showed a trend similar to that of the SGCs, but was only significantly higher for the highest dose of M3. The protective effect of M3 on SGCs was not reflected in any of the eCAP measures: no statistically significant differences were observed between groups in IPG effect nor between the M3 treatment groups and the control group using the pulse-train stimulation paradigm. In short, while a clear effect of M3 was observed on SGC survival, this was not clearly translated into functional preservation.
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Affiliation(s)
- Henk A Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands
| | | | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
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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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Gunewardene N, Ma Y, Lam P, Wagstaff S, Cortez-Jugo C, Hu Y, Caruso F, Richardson RT, Wise AK. Developing the supraparticle technology for round window-mediated drug administration into the cochlea. J Control Release 2023; 361:621-635. [PMID: 37572963 DOI: 10.1016/j.jconrel.2023.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/04/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
The semi-permeable round window membrane (RWM) is the gateway to the cochlea. Although the RWM is considered a minimally invasive and clinically accepted route for localised drug delivery to the cochlea, overcoming this barrier is challenging, hindering development of effective therapies for hearing loss. Neurotrophin 3 (NT3) is an emerging treatment option for hearing loss, but its therapeutic effect relies on sustained delivery across the RWM into the cochlea. Silica supraparticles (SPs) are drug delivery carriers capable of providing long-term NT3 delivery, when injected directly into the guinea pig cochlea. However, for clinical translation, a RWM delivery approach is desirable. Here, we aimed to test approaches to improve the longevity and biodistribution of NT3 inside the cochlea after RWM implantation of SPs in guinea pigs and cats. Three approaches were tested (i) coating the SPs to slow drug release (ii) improving the retention of SPs on the RWM using a clinically approved gel formulation and (iii) permeabilising the RWM with hyaluronic acid. A radioactive tracer (iodine 125: 125I) tagged to NT3 (125I NT3) was loaded into the SPs to characterise drug pharmacokinetics in vitro and in vivo. The neurotrophin-loaded SPs were coated using a chitosan and alginate layer-by-layer coating strategy, named as '(Chi/Alg)SPs', to promote long term drug release. The guinea pigs were implanted with 5× 125I NT3 loaded (Chi/Alg) SPs on the RWM, while cats were implanted with 30× (Chi/Alg) SPs. A cohort of animals were also implanted with SPs (controls). We found that the NT3 loaded (Chi/Alg)SPs exhibited a more linear release profile compared to NT3 loaded SPs alone. The 125I NT3 loaded (Chi/Alg)SPs in fibrin sealant had efficient drug loading (~5 μg of NT3 loaded per SP that weights ~50 μg) and elution capacities (~49% over one month) in vitro. Compared to the SPs in fibrin sealant, the (Chi/Alg)SPs in fibrin sealant had a significantly slower 125I NT3 drug release profile over the first 7 days in vitro (~12% for (Chi/Alg) SPs in fibrin sealant vs ~43% for SPs in fibrin sealant). One-month post-implantation of (Chi/Alg) SPs, gamma count measurements revealed an average of 0.3 μg NT3 remained in the guinea pig cochlea, while for the cat, 1.3 μg remained. Histological analysis of cochlear tissue revealed presence of a 125I NT3 signal localised in the basilar membrane of the lower basal turn in some cochleae after 4 weeks in guinea pigs and 8 weeks in cats. Comparatively, and in contrast to the in vitro release data, implantation of the SPs presented better NT3 retention and distribution inside the cochlea in both the guinea pigs and cats. No significant difference in drug entry was observed upon acute treatment of the RWM with hyaluronic acid. Collectively, our findings indicate that SPs and (Chi/Alg)SPs can facilitate drug transfer across the RWM, with detectable levels inside the cat cochlea even after 8 weeks with the intracochlear approach. This is the first study to examine neurotrophin pharmacokinetics in the cochlea for such an extended period of times in these two animal species. Whilst promising, we note that outcomes between animals were variable, and opposing results were found between in vitro and in vivo release studies. These findings have important clinical ramifications, emphasising the need to understand the physical properties and mechanics of this complex barrier in parallel with the development of therapies for hearing loss.
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Affiliation(s)
- Niliksha Gunewardene
- Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Medical Bionics, The University of Melbourne, Fitzroy, Victoria 3065, Australia.
| | - Yutian Ma
- Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Patrick Lam
- Bionics Institute, East Melbourne, Victoria 3002, Australia
| | | | - Christina Cortez-Jugo
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Yingjie Hu
- Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Medical Bionics, The University of Melbourne, Fitzroy, Victoria 3065, Australia; Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Frank Caruso
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Rachael T Richardson
- Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Medical Bionics, The University of Melbourne, Fitzroy, Victoria 3065, Australia; Department of Surgery (Otolaryngology), University of Melbourne, The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria 3002, Australia
| | - Andrew K Wise
- Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Medical Bionics, The University of Melbourne, Fitzroy, Victoria 3065, Australia.
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Sonoporation of the Round Window Membrane on a Sheep Model: A Safety Study. Pharmaceutics 2023; 15:pharmaceutics15020442. [PMID: 36839763 PMCID: PMC9964975 DOI: 10.3390/pharmaceutics15020442] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Sonoporation using microbubble-assisted ultrasound increases the permeability of a biological barrier to therapeutic molecules. Application of this method to the round window membrane could improve the delivery of therapeutics to the inner ear. The aim of this study was to assess the safety of sonoporation of the round window membrane in a sheep model. To achieve this objective, we assessed auditory function and cochlear heating, and analysed the metabolomics profiles of perilymph collected after sonoporation, comparing them with those of the control ear in the same animal. Six normal-hearing ewes were studied, with one sonoporation ear and one control ear for each. A mastoidectomy was performed on both ears. On the sonoporation side, Vevo MicroMarker® microbubbles (MBs; VisualSonics-Fujifilm, Amsterdam, The Netherlands) at a concentration of 2 × 108 MB/mL were locally injected into the middle ear and exposed to 1.1 MHz sinusoidal ultrasonic waves at 0.3 MPa negative peak pressure with 40% duty cycle and 100 μs interpulse period for 1 min; this was repeated three times with 1 min between applications. The sonoporation protocol did not induce any hearing impairment or toxic overheating compared with the control condition. The metabolomic analysis did not reveal any significant metabolic difference between perilymph samples from the sonoporation and control ears. The results suggest that sonoporation of the round window membrane does not cause damage to the inner ear in a sheep model.
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Kashizadeh A, Pastras C, Rabiee N, Mohseni-Dargah M, Mukherjee P, Asadnia M. Potential nanotechnology-based diagnostic and therapeutic approaches for Meniere's disease. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2022; 46:102599. [PMID: 36064032 DOI: 10.1016/j.nano.2022.102599] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Meniere's disease (MD) is a progressive inner ear disorder involving recurrent and prolonged episodes or attacks of vertigo with associated symptoms, resulting in a significantly reduced quality of life for sufferers. In most cases, MD starts in one ear; however, in one-third of patients, the disorder progresses to the other ear. Unfortunately, the etiology of the disease is unknown, making the development of effective treatments difficult. Nanomaterials, including nanoparticles (NPs) and nanocarriers, offer an array of novel diagnostic and therapeutic applications related to MD. NPs have specific features such as biocompatibility, biochemical stability, targetability, and enhanced visualization using imaging tools. This paper provides a comprehensive and critical review of recent advancements in nanotechnology-based diagnostic and therapeutic approaches for MD. Furthermore, the crucial challenges adversely affecting the use of nanoparticles to treat middle ear disorders are investigated. Finally, this paper provides recommendations and future directions for improving the performances of nanomaterials on theragnostic applications of MD.
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Affiliation(s)
- Afsaneh Kashizadeh
- School of Electrical and Computer Engineering, Shahid Beheshti University, Tehran 1983969411, Iran
| | - Christopher Pastras
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia; The Menière's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Navid Rabiee
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia
| | - Masoud Mohseni-Dargah
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia; Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Payal Mukherjee
- RPA Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Mohsen Asadnia
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
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Vink HA, Ramekers D, Thomeer HGXM, Versnel H. Combined brain-derived neurotrophic factor and neurotrophin-3 treatment is preferred over either one separately in the preservation of the auditory nerve in deafened guinea pigs. Front Mol Neurosci 2022; 15:935111. [PMID: 36226314 PMCID: PMC9549372 DOI: 10.3389/fnmol.2022.935111] [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: 05/03/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Severe hearing loss or deafness is often caused by cochlear hair cell loss and can be mitigated by a cochlear implant (CI). CIs target the auditory nerve, consisting of spiral ganglion cells (SGCs), which degenerate gradually, following hair cell loss. In animal models, it has been established that treatment with the neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) reduce SGC degeneration. In this study, we aimed to investigate whether treatment with both BDNF and NT-3 (Cocktail) is superior to treatment with each neurotrophin separately regarding cell preservation and neural responsiveness to electrical stimulation. To this end, deafened guinea pigs received neurotrophic treatment in their right ear via a gelatin sponge on the perforated round window membrane, followed by cochlear implantation 4 weeks later in the same ear for electrophysiological recordings to various stimulation paradigms. Normal-hearing and deafened untreated guinea pigs were included as positive and negative controls, respectively. Substantial SGC loss occurred in all deafened animals. Each of the neurotrophic treatments led to enhanced SGC survival mainly in the basal turn of the cochlea, gradually decreasing toward the apex. The Cocktail treatment resulted in the highest SGC survival in the treated ear, followed by BDNF, with the least protection of SGCs following NT-3 treatment. Survival of the SGC’s peripheral processes (PPs) followed the same trend in response to the treatment. However, survival of SGCs and PPs in the contralateral untreated ears was also highest in the Cocktail group. Consequently, analysis of the ratio between the treated and untreated ears showed that the BDNF group, which showed low SGC survival in the untreated ear, had the highest relative SGC survival of the three neurotrophin-treated groups. Neurotrophic treatment had positive effects in part of the electrically evoked compound action-potential recording paradigms. These effects were only observed for the BDNF or Cocktail treatment. We conclude that treatment with either BDNF or a cocktail of BDNF and NT-3 is preferred to NT-3 alone. Furthermore, since the Cocktail treatment resulted in better electrophysiological responsiveness and overall higher SGC survival than BDNF alone, we are inclined to recommend the Cocktail treatment rather than BDNF alone.
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Affiliation(s)
- Henk A. Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- *Correspondence: Dyan Ramekers,
| | - Hans G. X. M. Thomeer
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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12
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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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13
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Nguyen TN, Park JS. Intratympanic drug delivery systems to treat inner ear impairments. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2022. [DOI: 10.1007/s40005-022-00586-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Zhang Q, Wu M, Fang Y, Deng C, Shen HH, Tang Y, Wang Y. Dendritic Mesoporous Silica Hollow Spheres for Nano-Bioreactor Application. NANOMATERIALS 2022; 12:nano12111940. [PMID: 35683794 PMCID: PMC9182369 DOI: 10.3390/nano12111940] [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: 05/09/2022] [Revised: 05/26/2022] [Accepted: 06/03/2022] [Indexed: 12/10/2022]
Abstract
Mesoporous silica materials have attracted great research interest for various applications ranging from (bio)catalysis and sensing to drug delivery. It remains challenging to prepare hollow mesoporous silica nanoparticles (HMSN) with large center-radial mesopores that could provide a more efficient transport channel through the cell for guest molecules. Here, we propose a novel strategy for the preparation of HMSN with large dendritic mesopores to achieve higher enzyme loading capacity and more efficient bioreactors. The materials were prepared by combining barium sulfate nanoparticles (BaSO4 NP) as a hard template and the in situ-formed 3-aminophenol/formaldehyde resin as a porogen for directing the dendritic mesopores’ formation. HMSNs with different particle sizes, shell thicknesses, and pore structures have been prepared by choosing BaSO4 NP of various sizes and adjusting the amount of tetraethyl orthosilicate added in synthesis. The obtained HMSN-1.1 possesses a high pore volume (1.07 cm3 g−1), a large average pore size (10.9 nm), and dendritic mesopores that penetrated through the shell. The advantages of HMSNs are also demonstrated for enzyme (catalase) immobilization and subsequent use of catalase-loaded HMSNs as bioreactors for catalyzing the H2O2 degradation reaction. The hollow and dendritic mesoporous shell features of HMSNs provide abundant tunnels for molecular transport and more accessible surfaces for molecular adsorption, showing great promise in developing efficient nanoreactors and drug delivery vehicles.
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Affiliation(s)
- Qian Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, China; (Q.Z.); (M.W.); (Y.F.)
| | - Minying Wu
- Department of Chemistry, Fudan University, Shanghai 200433, China; (Q.Z.); (M.W.); (Y.F.)
| | - Yuanyuan Fang
- Department of Chemistry, Fudan University, Shanghai 200433, China; (Q.Z.); (M.W.); (Y.F.)
| | - Chao Deng
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou 325027, China;
| | - Hsin-Hui Shen
- Department of Materials Science and Engineering, Monash University, Clayton, VIC 3800, Australia;
| | - Yi Tang
- Department of Chemistry, Fudan University, Shanghai 200433, China; (Q.Z.); (M.W.); (Y.F.)
- Correspondence: (Y.T.); (Y.W.)
| | - Yajun Wang
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou 325027, China;
- Correspondence: (Y.T.); (Y.W.)
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15
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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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16
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Li L, Luo J, Lin X, Tan J, Li P. Nanomaterials for Inner Ear Diseases: Challenges, Limitations and Opportunities. MATERIALS (BASEL, SWITZERLAND) 2022; 15:3780. [PMID: 35683076 PMCID: PMC9181474 DOI: 10.3390/ma15113780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/22/2022] [Accepted: 05/18/2022] [Indexed: 02/01/2023]
Abstract
The inner ear is located deep in the temporal bone and has a complex anatomy. It is difficult to observe and obtain pathological tissues directly. Therefore, the diagnosis and treatment of inner ear diseases have always been a major clinical problem. The onset of inner ear disease can be accompanied by symptoms such as hearing loss, dizziness and tinnitus, which seriously affect people's lives. Nanoparticles have the characteristics of small size, high bioavailability and strong plasticity. With the development of related research on nanoparticles in inner ear diseases, nanoparticles have gradually become a research hotspot in inner ear diseases. This review briefly summarizes the research progress, opportunities and challenges of the application of nanoparticles in inner ear diseases.
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Affiliation(s)
- Liling Li
- Department of Otolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, No.600 Tianhe Road, Guangzhou 510630, China; (L.L.); (J.L.); (X.L.)
| | - Jia Luo
- Department of Otolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, No.600 Tianhe Road, Guangzhou 510630, China; (L.L.); (J.L.); (X.L.)
| | - Xuexin Lin
- Department of Otolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, No.600 Tianhe Road, Guangzhou 510630, China; (L.L.); (J.L.); (X.L.)
| | - Jingqian Tan
- Department of Otolaryngology Head and Neck Surgery, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen 518033, China;
| | - Peng Li
- Department of Otolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, No.600 Tianhe Road, Guangzhou 510630, China; (L.L.); (J.L.); (X.L.)
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17
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Abstract
INTRODUCTION More than 5% of the world's population have a disabling hearing loss which can be managed by hearing aids or implanted electrical devices. However, outcomes are highly variable, and the sound perceived by recipients is far from perfect. Sparked by the discovery of progenitor cells in the cochlea and rapid progress in drug delivery to the cochlea, biological and pharmaceutical therapies are currently in development to improve the function of the cochlear implant or eliminate the need for it altogether. AREAS COVERED This review highlights progress in emerging regenerative strategies to restore hearing and adjunct therapies to augment the cochlear implant. Novel approaches include the reprogramming of progenitor cells to restore the sensory hair cell population in the cochlea, gene therapy and gene editing to treat hereditary and acquired hearing loss. A detailed review of optogenetics is also presented as a technique that could enable optical stimulation of the spiral ganglion neurons, replacing or complementing electrical stimulation. EXPERT OPINION Increasing evidence of substantial reversal of hearing loss in animal models, alongside rapid advances in delivery strategies to the cochlea and learnings from clinical trials will amalgamate into a biological or pharmaceutical therapy to replace or complement the cochlear implant.
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Affiliation(s)
- Elise Ajay
- Bionics Institute, East Melbourne, Victoria, Australia.,University of Melbourne, Department of Engineering
| | | | - Rachael Richardson
- Bionics Institute, East Melbourne, Victoria, Australia.,University of Melbourne, Medical Bionics Department, Parkville, Victoria, Australia.,University of Melbourne, Department of Surgery (Otolaryngology), East Melbourne, Victoria, Australia
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18
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Wille I, Harre J, Oehmichen S, Lindemann M, Menzel H, Ehlert N, Lenarz T, Warnecke A, Behrens P. Development of Neuronal Guidance Fibers for Stimulating Electrodes: Basic Construction and Delivery of a Growth Factor. Front Bioeng Biotechnol 2022; 10:776890. [PMID: 35141211 PMCID: PMC8819688 DOI: 10.3389/fbioe.2022.776890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/05/2022] [Indexed: 12/03/2022] Open
Abstract
State-of-the-art treatment for sensorineural hearing loss is based on electrical stimulation of residual spiral ganglion neurons (SGNs) with cochlear implants (CIs). Due to the anatomical gap between the electrode contacts of the CI and the residual afferent fibers of the SGNs, spatial spreading of the stimulation signal hampers focused neuronal stimulation. Also, the efficiency of a CI is limited because SGNs degenerate over time due to loss of trophic support. A promising option to close the anatomical gap is to install fibers as artificial nerve guidance structures on the surface of the implant and install on these fibers drug delivery systems releasing neuroprotective agents. Here, we describe the first steps in this direction. In the present study, suture yarns made of biodegradable polymers (polyglycolide/poly-ε-caprolactone) serve as the basic fiber material. In addition to the unmodified fiber, also fibers modified with amine groups were employed. Cell culture investigations with NIH 3T3 fibroblasts attested good cytocompatibility to both types of fibers. The fibers were then coated with the extracellular matrix component heparan sulfate (HS) as a biomimetic of the extracellular matrix. HS is known to bind, stabilize, modulate, and sustainably release growth factors. Here, we loaded the HS-carrying fibers with the brain-derived neurotrophic factor (BDNF) which is known to act neuroprotectively. Release of this neurotrophic factor from the fibers was followed over a period of 110 days. Cell culture investigations with spiral ganglion cells, using the supernatants from the release studies, showed that the BDNF delivered from the fibers drastically increased the survival rate of SGNs in vitro. Thus, biodegradable polymer fibers with attached HS and loaded with BDNF are suitable for the protection and support of SGNs. Moreover, they present a promising base material for the further development towards a future neuronal guiding scaffold.
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Affiliation(s)
- Inga Wille
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Jennifer Harre
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Sarah Oehmichen
- Institut für Technische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Maren Lindemann
- Institut für Technische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Henning Menzel
- Institut für Technische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Nina Ehlert
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Thomas Lenarz
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Peter Behrens
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
- Cluster of Excellence PhoenixD, Hannover, Germany
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Gunewardene N, Lam P, Ma Y, Caruso F, Wagstaff S, Richardson RT, Wise AK. Pharmacokinetics and biodistribution of supraparticle-delivered neurotrophin 3 in the guinea pig cochlea. J Control Release 2022; 342:295-307. [PMID: 34999140 DOI: 10.1016/j.jconrel.2021.12.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 12/29/2021] [Indexed: 02/06/2023]
Abstract
Hearing loss is the most prevalent sensory disorder affecting nearly half a billion people worldwide. Aside from devices to assist hearing, such as hearing aids and cochlear implants, a drug treatment for hearing loss has yet to be developed. The neurotrophin family of growth factors has long been established as a potential therapy, however delivery of these factors into the inner ear at therapeutic levels over a sustained period of time has remained a challenge restricting clinical translation. We previously demonstrated that direct delivery of exogenous neurotrophin-3 (NT3) in the guinea pig cochleae via a bolus injection was rapidly cleared from the inner ear, with almost complete elimination 3 days post-treatment. Here, we explored the potential of suprapaticles (SPs) for NT3 delivery to the inner ear to achieve sustained delivery over time. SPs are porous spheroid structures comprised of smaller colloidal silica nanoparticles that provide a platform for long-term controlled release of therapeutics. This study aimed to assess the pharmacokinetics and biodistribution of SP-delivered NT3. We used a radioactive tracer (iodine 125: 125I) to label the NT3 to determine the loading, retention and distribution of NT3 delivered via SPs. Gamma measurements taken from 125I NT3 loaded SPs revealed high drug loading (an average of 5.3 μg of NT3 loaded per SP weighing 50 μg) and elution capacities in vitro (67% cumulative release over one month). Whole cochlear gamma measurements from SP-implanted cochleae harvested at various time points revealed detection of 125I NT3 in the guinea pig cochlea after one month, with 3.6 and 10% of the loaded drug remaining in the intracochlear and round window-implanted cochleae respectively. Autoradiography analysis of cochlear micro-sections revealed widespread 125I NT3 distribution after intracochlear SP delivery, but more restricted distribution with the round window delivery approach. Collectively, drug delivery into the inner ear using SPs support sustained, long-term availability and release of neurotrophins in the inner ear.
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Affiliation(s)
- Niliksha Gunewardene
- Bionics Institute, Melbourne, Australia; Medical Bionics Department, University of Melbourne, Australia.
| | | | - Yutian Ma
- Bionics Institute, Melbourne, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Rachael T Richardson
- Bionics Institute, Melbourne, Australia; Medical Bionics Department, University of Melbourne, Australia; Department of Surgery (Otolaryngology), University of Melbourne, Australia
| | - Andrew K Wise
- Bionics Institute, Melbourne, Australia; Medical Bionics Department, University of Melbourne, Australia; Department of Surgery (Otolaryngology), University of Melbourne, Australia.
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20
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Shew M, Wichova H, Warnecke A, Lenarz T, Staecker H. Evaluating Neurotrophin Signaling Using MicroRNA Perilymph Profiling in Cochlear Implant Patients With and Without Residual Hearing. Otol Neurotol 2021; 42:e1125-e1133. [PMID: 33973949 DOI: 10.1097/mao.0000000000003182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
HYPOTHESIS MicroRNAs predicted to regulate neurotrophin signaling can be found in human perilymph. BACKGROUND Animal and human temporal bone studies suggest that spiral ganglion health can affect cochlear implant (CI) outcomes. Neurotrophins have been identified as a key factor in the maintenance of spiral ganglion health. Changes in miRNAs may regulate neurotrophin signaling and may reflect neurotrophin expression levels. METHODS Perilymph sampling was carried out in 18 patients undergoing cochlear implantation or stapedotomy. Expression of miRNAs in perilymph was evaluated using an Agilent miRNA gene chip. Using ingenuity pathway analysis (IPA) software, miRNAs targeting neurotrophin signaling pathway genes present in a cochlear cDNA library were annotated. Expression levels of miRNAs in perilymph were correlated to the patients' preoperative pure-tone average. RESULTS Expression of mRNAs coding for neurotrophins and their receptors were identified in tissue obtained from normal human cochlea during skull base surgery. We identified miRNAs predicted to regulate these signaling cascades, including miR-1207-5p, miR-4651, miR-103-3p, miR-100-5p, miR-221-3p, miR-200-3p. There was a correlation between poor preoperative hearing and lower expression of miR-1207 (predicted to regulate NTR3) and miR-4651 (predicted to regulate NTR2). Additionally, miR-3960, miR-4481, and miR-675 showed significant differences in expression level when comparing mild and profound hearing loss patients. CONCLUSIONS Expression of some miRNAs that are predicted to regulate neurotrophin signaling in the perilymph of cochlear implant patients vary with the patient's level of residual hearing. These miRNAs may serve as biomarkers for changes in neurotrophin signaling.
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Affiliation(s)
- Matthew Shew
- Department of Otolaryngology Head and Neck Surgery, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - Helena Wichova
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
| | - Athanasia Warnecke
- Department of Otolaryngology, Medizinische Hochschule Hannover, Hannover
- Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 1077), Germany
| | - Thomas Lenarz
- Department of Otolaryngology, Medizinische Hochschule Hannover, Hannover
- Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 1077), Germany
| | - Hinrich Staecker
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
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21
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Gurner KH, Richardson JJ, Harvey AJ, Gardner DK. A pilot study investigating a novel particle-based growth factor delivery system for preimplantation embryo culture. Hum Reprod 2021; 36:1776-1783. [PMID: 33975346 DOI: 10.1093/humrep/deab105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/22/2021] [Indexed: 11/15/2022] Open
Abstract
STUDY QUESTION Can vascular endothelial growth factor (VEGF)-loaded silica supraparticles (V-SPs) be used as a novel mode of delivering VEGF to the developing preimplantation embryo in vitro? SUMMARY ANSWER Supplementation of embryo culture media with V-SPs promoted embryonic development in a manner equivalent to media supplemented with free VEGF. WHAT IS KNOWN ALREADY VEGF is a maternally derived growth factor that promotes preimplantation embryonic development in vitro. However, its use in clinical media has limitations due to its low stability in solution. STUDY DESIGN, SIZE, DURATION This study was a laboratory-based analysis utilising a mouse model. V-SPs were prepared in vitro and supplemented to embryonic culture media. The bioactivity of V-SPs was determined by analysis of blastocyst developmental outcomes (blastocyst development rate and total cell number). PARTICIPANTS/MATERIALS, SETTING, METHODS SPs were loaded with fluorescently labelled VEGF and release kinetics were characterised. Bioactivity of unlabelled VEGF released from V-SPs was determined by analysis of embryo developmental outcomes (blastocyst developmental rate and total cell number) following individual mouse embryo culture in 20 µl of G1/G2 media at 5% oxygen, supplemented with 10 ng/ml recombinant mouse VEGF in solution or with V-SPs. The bioactivity of freeze-dried V-SPs was also assessed to determine the efficacy of cryostorage. MAIN RESULTS AND THE ROLE OF CHANCE VEGF release kinetics were characterised by an initial burst of VEGF from loaded spheres followed by a consistent lower level of VEGF release over 48 h. VEGF released from V-SPs resulted in significant increases in total blastocyst cell number relative to the control (P < 0.001), replicating the effects of medium freely supplemented with fresh VEGF (P < 0.001). Similarly, freeze dried V-SPs exerted comparable effects on embryonic development (P < 0.05). LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION In this proof of principle study, the effects of V-SPs on embryonic development were only analysed in a mouse model. WIDER IMPLICATIONS OF THE FINDINGS These findings suggest that SPs represent a novel method by which a targeted dose of therapeutic agents (e.g. bioactive VEGF) can be delivered to the developing in vitro embryo to promote embryonic development, an approach that negates the breakdown of VEGF associated with storage in solution. As such, V-SPs may be an alternative and effective method of delivering bioactive VEGF to the developing in vitro embryo; however, the potential use of V-SPs in clinical IVF requires further investigation. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by the University of Melbourne. The authors have no conflict of interest to declare.
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Affiliation(s)
- Kathryn H Gurner
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Joseph J Richardson
- Department of Chemical Engineering, The University of Melbourne, Parkville, VIC, Australia
| | - Alexandra J Harvey
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - David K Gardner
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
- Melbourne IVF, East Melbourne, VIC, Australia
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22
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Carlyon RP, Guérit F, Deeks JM, Harland A, Gransier R, Wouters J, de Rijk SR, Bance M. Using Interleaved Stimulation to Measure the Size and Selectivity of the Sustained Phase-Locked Neural Response to Cochlear Implant Stimulation. J Assoc Res Otolaryngol 2021; 22:141-159. [PMID: 33492562 PMCID: PMC7943679 DOI: 10.1007/s10162-020-00783-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/21/2020] [Indexed: 02/08/2023] Open
Abstract
We measured the sustained neural response to electrical stimulation by a cochlear implant (CI). To do so, we interleaved two stimuli with frequencies F1 and F2 Hz and recorded a neural distortion response (NDR) at F2-F1 Hz. We show that, because any one time point contains only the F1 or F2 stimulus, the instantaneous nonlinearities typical of electrical artefact should not produce distortion at this frequency. However, if the stimulus is smoothed, such as by charge integration at the nerve membrane, subsequent (neural) nonlinearities can produce a component at F2-F1 Hz. We stimulated a single CI electrode with interleaved sinusoids or interleaved amplitude-modulated pulse trains such that F2 = 1.5F1, and found no evidence for an NDR when F2-F1 was between 90 and 120 Hz. However, interleaved amplitude-modulated pulse trains with F2-F1~40 Hz revealed a substantial NDR with a group delay of about 45 ms, consistent with a thalamic and/or cortical response. The NDR could be measured even from recording electrodes adjacent to the implant and at the highest pulse rates (> 4000 pps) used clinically. We then measured the selectivity of this sustained response by presenting F1 and F2 to different electrodes and at different between-electrode distances. This revealed a broad tuning that, we argue, reflects the overlap between the excitation elicited by the two electrodes. Our results also provide a glimpse of the neural nonlinearity in the auditory system, unaffected by the biomechanical cochlear nonlinearities that accompany acoustic stimulation. Several potential clinical applications of our findings are discussed.
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Affiliation(s)
- Robert P Carlyon
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, 15 Chaucer Rd, Cambridge, CB2 7EF, England.
| | - François Guérit
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, 15 Chaucer Rd, Cambridge, CB2 7EF, England
| | - John M Deeks
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, 15 Chaucer Rd, Cambridge, CB2 7EF, England
| | - Andrew Harland
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, 15 Chaucer Rd, Cambridge, CB2 7EF, England
| | - Robin Gransier
- Dept. of Neurosciences, ExpORL, KU Leuven, Herestraat 49 box 721, 3000, Leuven, Belgium
| | - Jan Wouters
- Dept. of Neurosciences, ExpORL, KU Leuven, Herestraat 49 box 721, 3000, Leuven, Belgium
| | - Simone R de Rijk
- Cambridge Hearing Group, Dept. Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, England
| | - Manohar Bance
- Cambridge Hearing Group, Dept. Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, England
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23
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Shepherd RK, Carter PM, Dalrymple AN, Enke YL, Wise AK, Nguyen T, Firth J, Thompson A, Fallon JB. Platinum dissolution and tissue response following long-term electrical stimulation at high charge densities. J Neural Eng 2021; 18:10.1088/1741-2552/abe5ba. [PMID: 33578409 PMCID: PMC8711780 DOI: 10.1088/1741-2552/abe5ba] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/12/2021] [Indexed: 11/11/2022]
Abstract
Objective. Established guidelines for safe levels of electrical stimulation for neural prostheses are based on a limited range of the stimulus parameters used clinically. Recent studies have reported particulate platinum (Pt) associated with long-term clinical use of these devices, highlighting the need for more carefully defined safety limits. We previously reported no adverse effects of Pt corrosion products in the cochleae of guinea pigs following 4 weeks of electrical stimulation using charge densities far greater than the published safe limits for cochlear implants. The present study examines the histopathological effects of Pt within the cochlea following continuous stimulation at a charge density well above the defined safe limits for periods up to 6 months.Approach. Six cats were bilaterally implanted with Pt electrode arrays and unilaterally stimulated using charge balanced current pulses at a charge density of 267μC cm-2phase-1using a tripolar electrode configuration. Electrochemical measurements were made throughout the implant duration and evoked potentials recorded at the outset and on completion of the stimulation program. Cochleae were examined histologically for particulate Pt, tissue response, and auditory nerve survival; electrodes were examined for surface corrosion; and cochlea, brain, kidney, and liver tissue analysed for trace levels of Pt.Main results. Chronic stimulation resulted in both a significant increase in tissue response and particulate Pt within the tissue capsule surrounding the electrode array compared with implanted, unstimulated control cochleae. Importantly, there was no stimulus-induced loss of auditory neurons (ANs) or increase in evoked potential thresholds. Stimulated electrodes were significantly more corroded compared with unstimulated electrodes. Trace analysis revealed Pt in both stimulated and control cochleae although significantly greater levels were detected within stimulated cochleae. There was no evidence of Pt in brain or liver; however, trace levels of Pt were recorded in the kidneys of two animals. Finally, increased charge storage capacity and charge injection limit reflected the more extensive electrode corrosion associated with stimulated electrodes.Significance. Long-term electrical stimulation of Pt electrodes at a charge density well above existing safety limits and nearly an order of magnitude higher than levels used clinically, does not adversely affect the AN population or reduce neural function, despite a stimulus-induced tissue response and the accumulation of Pt corrosion product. The mechanism resulting in Pt within the unstimulated cochlea is unclear, while the level of Pt observed systemically following stimulation at these very high charge densities does not appear to be of clinical significance.
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Affiliation(s)
- Robert K Shepherd
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
- Medical Bionics Department, University of Melbourne, Melbourne, Australia
| | | | - Ashley N Dalrymple
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | | | - Andrew K Wise
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
- Medical Bionics Department, University of Melbourne, Melbourne, Australia
| | - Trung Nguyen
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
| | - James Firth
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
| | - Alex Thompson
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
| | - James B Fallon
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia
- Medical Bionics Department, University of Melbourne, Melbourne, Australia
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24
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Mustfa SA, Maurizi E, McGrath J, Chiappini C. Nanomedicine Approaches to Negotiate Local Biobarriers for Topical Drug Delivery. ADVANCED THERAPEUTICS 2021. [DOI: 10.1002/adtp.202000160] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Salman Ahmad Mustfa
- Centre for Craniofacial and Regenerative Biology King's College London London SE1 9RT UK
| | - Eleonora Maurizi
- Dipartimento di Medicina e Chirurgia Università di Parma Parma 43121 Italy
| | - John McGrath
- St John's Institute of Dermatology King's College London London SE1 9RT UK
| | - Ciro Chiappini
- Centre for Craniofacial and Regenerative Biology King's College London London SE1 9RT UK
- London Centre for Nanotechnology King's College London London WC2R 2LS UK
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25
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Sekiya T, Holley MC. Cell Transplantation to Restore Lost Auditory Nerve Function is a Realistic Clinical Opportunity. Cell Transplant 2021; 30:9636897211035076. [PMID: 34498511 PMCID: PMC8438274 DOI: 10.1177/09636897211035076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Hearing is one of our most important means of communication. Disabling hearing loss (DHL) is a long-standing, unmet problem in medicine, and in many elderly people, it leads to social isolation, depression, and even dementia. Traditionally, major efforts to cure DHL have focused on hair cells (HCs). However, the auditory nerve is also important because it transmits electrical signals generated by HCs to the brainstem. Its function is critical for the success of cochlear implants as well as for future therapies for HC regeneration. Over the past two decades, cell transplantation has emerged as a promising therapeutic option for restoring lost auditory nerve function, and two independent studies on animal models show that cell transplantation can lead to functional recovery. In this article, we consider the approaches most likely to achieve success in the clinic. We conclude that the structure and biochemical integrity of the auditory nerve is critical and that it is important to preserve the remaining neural scaffold, and in particular the glial scar, for the functional integration of donor cells. To exploit the natural, autologous cell scaffold and to minimize the deleterious effects of surgery, donor cells can be placed relatively easily on the surface of the nerve endoscopically. In this context, the selection of donor cells is a critical issue. Nevertheless, there is now a very realistic possibility for clinical application of cell transplantation for several different types of hearing loss.
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Affiliation(s)
- Tetsuji Sekiya
- Department of Otolaryngology, Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Neurological Surgery, Hikone Chuo Hospital, Hikone, Japan
- Tetsuji Sekiya, Department of Otolaryngology, Head and Neck Surgery, Kyoto University Graduate School of Medicine, 606-8507 Kyoto, Japan,.
| | - Matthew C. Holley
- Department of Biomedical Science, University of Sheffield, Firth Court, Sheffield, England
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26
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Vink HA, Versnel H, Kroon S, Klis SFL, Ramekers D. BDNF-mediated preservation of spiral ganglion cell peripheral processes and axons in comparison to that of their cell bodies. Hear Res 2020; 400:108114. [PMID: 33271438 DOI: 10.1016/j.heares.2020.108114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/21/2020] [Accepted: 11/10/2020] [Indexed: 01/19/2023]
Abstract
Treatment with neurotrophins prevents degeneration of spiral ganglion cells (SGCs) after severe hair cell loss. In a previous study we demonstrated a long-lasting effect with brain-derived neurotrophic factor (BDNF) after cessation of treatment. In that study the survival of the SGC cell bodies was examined. Here we address the question whether their peripheral processes and central processes (axons) were protected by this treatment as well in the cochleas of the aforementioned study. Guinea pigs were deafened by co-administration of kanamycin and furosemide. Two weeks after deafening the right cochleas were implanted with an intracochlear electrode array combined with a cannula connected to an osmotic pump filled with BDNF solution. Four weeks later the treatment was stopped by surgically removing the osmotic pump. At that point, or another four or eight weeks later, the animals were sacrificed for histological analysis. Control groups consisted of normal-hearing animals, and three groups of deafened animals: two-weeks-deaf untreated animals, and six- and fourteen-weeks-deaf sham-treated animals. Cochleas were processed for analysis of: (1) the myelinated portion of peripheral processes in the osseous spiral lamina, (2) the cell bodies in Rosenthal's canal, and (3) axons in the internal acoustic meatus. Packing densities and cross-sectional areas were determined using light microscopy. Up to eight weeks after treatment cessation the numbers of peripheral processes and axons were significantly higher than in untreated cochleas of control animals. Whereas the numbers of cell bodies and axons were similar to those at the start of treatment, the peripheral processes were significantly less well preserved. This smaller protective effect was found mainly in the apical turns. Strategies to prevent SGC degeneration after hair cell loss should consider the differential effects on the various neural elements.
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Affiliation(s)
- Henk A Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
| | - Steven Kroon
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands
| | - Sjaak F L Klis
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
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27
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Lam P, Gunewardene N, Ma Y, Caruso F, Nguyen T, Flynn B, Wise AK, Richardson RT. A radiolabeled drug tracing method to study neurotrophin-3 retention and distribution in the cochlea after nano-based local delivery. MethodsX 2020; 7:101078. [PMID: 33072529 PMCID: PMC7549113 DOI: 10.1016/j.mex.2020.101078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/21/2020] [Indexed: 12/02/2022] Open
Abstract
Hearing loss is the most common sensory deficit worldwide with no approved therapeutics for treatment. Local neurotrophin delivery into the cochlea has shown great potential in protecting and repairing the sensory cells important for hearing. However, delivery of these factors into the inner ear at therapeutic levels over a sustained period of time has remained a challenge restricting clinical translation. We have developed a method to test the pharmacokinetics of neurotrophin released from porous silica particles called ‘supraparticles’ that can provide sustained release of neurotrophins to the inner ear.This report describes a radiolabeling method to examine neurotrophin retention and distribution in the cochlea. The neurotrophin was labeled with a radioactive tracer (iodine 125: 125I) and delivered into the cochlea via the supraparticle system. Gamma counts reveal drug levels and clearance in the intact cochlea, as well as accumulation in off-target organs (safety test). Autoradiography analyses using film and emulsion permit quantification and visualization of drug distribution at the cellular level. The method has a detection limit of 0.8 pg of radiolabeled neurotrophin-3 in cochlear sections exposed to film. The tracer 125I with a half-life of 59.4 days can be used to label other drugs/substances with a tyrosine residue and therefore be broadly applicable for long-term pharmacokinetic studies in other systems.
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Affiliation(s)
- Patrick Lam
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Medical Bionics, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Niliksha Gunewardene
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Medical Bionics, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Yutian Ma
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Trung Nguyen
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Medical Bionics, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Brianna Flynn
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Medical Bionics, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Andrew K. Wise
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Medical Bionics, University of Melbourne, Fitzroy, Victoria 3065, Australia
- University of Melbourne, Department of Otolaryngology, The Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
| | - Rachael T. Richardson
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Medical Bionics, University of Melbourne, Fitzroy, Victoria 3065, Australia
- University of Melbourne, Department of Otolaryngology, The Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
- Corresponding author at: Bionics Institute, East Melbourne, Victoria 3002, Australia.
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28
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Shepherd RK, Carter PM, Enke YL, Thompson A, Flynn B, Trang EP, Dalrymple AN, Fallon JB. Chronic intracochlear electrical stimulation at high charge densities: reducing platinum dissolution. J Neural Eng 2020; 17:056009. [DOI: 10.1088/1741-2552/abb7a6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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29
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Dalrymple AN, Huynh M, Nayagam BA, Lee CD, Weiland GR, Petrossians A, J J, Iii W, Fallon JB, Shepherd RK. Electrochemical and biological characterization of thin-film platinum-iridium alloy electrode coatings: a chronic in vivo study. J Neural Eng 2020; 17:036012. [PMID: 32408281 DOI: 10.1088/1741-2552/ab933d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To evaluate the electrochemical properties, biological response, and surface characterization of an electrodeposited Platinum-Iridium (Pt-Ir) electrode coating on cochlear implants subjected to chronic stimulation in vivo. APPROACH Electrochemical impedance spectroscopy (EIS), charge storage capacity (CSC), charge injection limit (CIL), and voltage transient (VT) impedance were measured bench-top before and after implant and in vivo. Coated Pt-Ir and uncoated Pt electrode arrays were implanted into cochlea of normal hearing rats and stimulated for ∼4 h d, 5 d week-1 for 5 weeks at levels within the normal clinical range. Neural function was monitored using electrically-evoked auditory brainstem responses. After explant, the electrode surfaces were assessed, and cochleae examined histologically. MAIN RESULTS When measured on bench-top before and after stimulation, Pt-Ir coated electrodes had significantly lower VT impedance (p < 0.001) and significantly higher CSC (p < 0.001) and CIL (p < 0.001) compared to uncoated Pt electrodes. In vivo, the CSC and CIL of Pt-Ir were significantly higher than Pt throughout the implantation period (p= 0.047 and p< 0.001, respectively); however, the VT impedance (p= 0.3) was not. There was no difference in foreign body response between material cohorts, although cochleae implanted with coated electrodes contained small deposits of Pt-Ir. There was no evidence of increased neural loss or loss of neural function in either group. Surface examination revealed no Pt corrosion on any electrodes. SIGNIFICANCE Electrodeposited Pt-Ir electrodes demonstrated significant improvements in electrochemical performance on the bench-top and in vivo compared to uncoated Pt. Neural function and tissue response to Pt-Ir electrodes were not different from uncoated Pt, despite small deposits of Pt-Ir in the tissue capsule. Electrodeposited Pt-Ir coatings offer promise as an improved electrode coating for active neural prostheses.
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30
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A new method for three-dimensional immunofluorescence study of the cochlea. Hear Res 2020; 392:107956. [PMID: 32464455 DOI: 10.1016/j.heares.2020.107956] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 03/13/2020] [Accepted: 03/26/2020] [Indexed: 01/07/2023]
Abstract
Visualisation of cochlear histopathology in three-dimensions has been long desired in the field of hearing research. This paper outlines a technique that has made this possible and shows a research application in the field of hearing protection after cochlear implantation. The technique utilises robust immunofluorescent labelling followed by effective tissue clearing and fast image acquisition using Light Sheet Microscopy. We can access the health of individual components by immunofluorescent detection of proteins such as myosin VIIa to look at cochlear hair cells, NaKATPase alpha 3 to look at spiral ganglion neurons, and IBA1 to look at macrophages within a single cochlea, whilst maintaining the integrity of fine membranous structures and keeping the cochlear implant in place. This allows the tissue response to cochlear implantation to be studied in detail, including the immune reaction to the implant and the impact on the structure and health of neural components such as hair cells. This technique reduces time and labour required for sectioning of cochleae and can allow visualisation of cellular detail. Use of image analysis software allows conversion of high-resolution image stacks into three-dimensional interactive data sets so volumes and numbers of surfaces can be measured. Immunofluorescent whole cochlea labelling and Light Sheet Microscopy have the capacity to be applied to many questions in hearing research of both the cochlea and vestibular system.
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31
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Dalrymple AN, Robles UA, Huynh M, Nayagam BA, Green RA, Poole-Warren LA, Fallon JB, Shepherd RK. Electrochemical and biological performance of chronically stimulated conductive hydrogel electrodes. J Neural Eng 2020; 17:026018. [DOI: 10.1088/1741-2552/ab7cfc] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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32
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Shi C, Du G, Wang J, Sun P, Chen T. Polyelectrolyte-Surfactant Mesomorphous Complex Templating: A Versatile Approach for Hierarchically Porous Materials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:1851-1863. [PMID: 32036669 DOI: 10.1021/acs.langmuir.9b03513] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hierarchically porous materials have attracted great attention because of their potential applications in the fields of adsorption, catalysis, and biomedical systems. The art of manipulating different templates that are used for pore construction is the key to fabricating desired hierarchically porous structures. In this feature article, the polyelectrolyte-surfactant mesomorphous complex templating (PSMCT) approach, which was first developed by our group, is elaborated on. During the organic-inorganic self-assembly, the mesomorphous complex of the polyelectrolyte and oppositely charged surfactants would undergo in situ phase separation, which is the key to fabricating hierarchically porous materials. The recent progress in the utilization of the PSMCT method for the synthesis of hierarchically porous materials with tunable morphologies, mesophases, pore structures, and compositions is reviewed. Meanwhile, the functions of the hierarchically porous materials synthesized by the PSMCT method and their applications in adsorption, catalysis, drug delivery, and nanocasting are also briefly summarized.
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Affiliation(s)
- Chengxiang Shi
- Institute of New Catalytic Materials Science, School of Materials Science and Engineering, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Nankai University, Tianjin 300350, P. R. China
| | - Guo Du
- Institute of New Catalytic Materials Science, School of Materials Science and Engineering, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Nankai University, Tianjin 300350, P. R. China
| | - Jingui Wang
- Institute of New Catalytic Materials Science, School of Materials Science and Engineering, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Nankai University, Tianjin 300350, P. R. China
| | - Pingchuan Sun
- Key Laboratory of Functional Polymer Materials (MOE), College of Chemistry, Nankai University, Tianjin 300071, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, P. R. China
| | - Tiehong Chen
- Institute of New Catalytic Materials Science, School of Materials Science and Engineering, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Nankai University, Tianjin 300350, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, P. R. China
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Mehta AH, Lu H, Oxenham AJ. The Perception of Multiple Simultaneous Pitches as a Function of Number of Spectral Channels and Spectral Spread in a Noise-Excited Envelope Vocoder. J Assoc Res Otolaryngol 2020; 21:61-72. [PMID: 32048077 DOI: 10.1007/s10162-019-00738-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 10/30/2019] [Indexed: 01/06/2023] Open
Abstract
Cochlear implant (CI) listeners typically perform poorly on tasks involving the pitch of complex tones. This limitation in performance is thought to be mainly due to the restricted number of active channels and the broad current spread that leads to channel interactions and subsequent loss of precise spectral information, with temporal information limited primarily to temporal-envelope cues. Little is known about the degree of spectral resolution required to perceive combinations of multiple pitches, or a single pitch in the presence of other interfering tones in the same spectral region. This study used noise-excited envelope vocoders that simulate the limited resolution of CIs to explore the perception of multiple pitches presented simultaneously. The results show that the resolution required for perceiving multiple complex pitches is comparable to that found in a previous study using single complex tones. Although relatively high performance can be achieved with 48 channels, performance remained near chance when even limited spectral spread (with filter slopes as steep as 144 dB/octave) was introduced to the simulations. Overall, these tight constraints suggest that current CI technology will not be able to convey the pitches of combinations of spectrally overlapping complex tones.
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Affiliation(s)
- Anahita H Mehta
- Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 East River Parkway, Minneapolis, MN, 55455, USA.
| | - Hao Lu
- Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 East River Parkway, Minneapolis, MN, 55455, USA
| | - Andrew J Oxenham
- Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 East River Parkway, Minneapolis, MN, 55455, USA
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Rathnam C, Chueng STD, Ying YLM, Lee KB, Kwan K. Developments in Bio-Inspired Nanomaterials for Therapeutic Delivery to Treat Hearing Loss. Front Cell Neurosci 2019; 13:493. [PMID: 31780898 PMCID: PMC6851168 DOI: 10.3389/fncel.2019.00493] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 10/21/2019] [Indexed: 01/10/2023] Open
Abstract
Sensorineural hearing loss affects millions of people worldwide and is a growing concern in the aging population. Treatment using aminoglycoside antibiotics for infection and exposure to loud sounds contribute to the degeneration of cochlear hair cells and spiral ganglion neurons. Cell loss impacts cochlear function and causes hearing loss in ∼ 15% of adult Americans (∼36 million). The number of individuals with hearing loss will likely grow with increasing lifespans. Current prosthesis such as hearing aids and cochlear implants can ameliorate hearing loss. However, hearing aids are ineffective if hair cells or spiral ganglion neurons are severely damaged, and cochlear implants are ineffective without properly functioning spiral ganglion neurons. As such, strategies that alleviate hearing loss by preventing degeneration or promoting cell replacement are urgently needed. Despite showing great promise from in vitro studies, the complexity and delicate nature of the inner ear poses a huge challenge for delivering therapeutics. To mitigate risks and complications associated with surgery, new technologies and methodologies have emerged for efficient delivery of therapeutics. We will focus on biomaterials that allow controlled and local drug delivery into the inner ear. The rapid development of microsurgical techniques in conjunction with novel bio- and nanomaterials for sustained drug delivery appears bright for hearing loss treatment.
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Affiliation(s)
- Christopher Rathnam
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
| | - Sy-Tsong Dean Chueng
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
| | - Yu-Lan Mary Ying
- Department of Otolaryngology Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Ki-Bum Lee
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States.,Stem Cell Research Center and Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
| | - Kelvin Kwan
- Stem Cell Research Center and Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, United States.,Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
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35
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Leso V, Fontana L, Ercolano ML, Romano R, Iavicoli I. Opportunities and challenging issues of nanomaterials in otological fields: an occupational health perspective. Nanomedicine (Lond) 2019; 14:2613-2629. [PMID: 31609676 DOI: 10.2217/nnm-2019-0114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Nanotechnology may offer innovative solutions to overcome the physiological and anatomical barriers that make the diagnosis and treatment of ear diseases an extremely challenging issue. However, despite the solutions provided by nano-applications, the still little-known toxicological behavior of nanomaterials raised scientific concerns regarding their biosafety for treated patients and exposed workers. Therefore, this review provides an overview on recent developments and upcoming opportunities in nanoscale otological applications, and critically assesses possible adverse effects of nanosized compounds on ear structures and hearing functionality. Although such preliminary data do not allow to draw definite strategies for the evaluation of nanomaterial ototoxicity, they can still be useful to improve scientific community and workforce awareness regarding possible nanomaterial adverse effects on ear.
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Affiliation(s)
- Veruscka Leso
- Department of Public Health, Section of Occupational Medicine, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Luca Fontana
- Department of Occupational & Environmental Medicine, Epidemiology & Hygiene, Italian Workers' Compensation Authority (INAIL), Via di Fontana Candida 1, 00040 Monte Porzio Catone, Rome, Italy
| | - Maria Luigia Ercolano
- Department of Public Health, Section of Occupational Medicine, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Rosaria Romano
- Department of Public Health, Section of Occupational Medicine, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Ivo Iavicoli
- Department of Public Health, Section of Occupational Medicine, University of Naples Federico II, Via Sergio Pansini 5, 80131 Naples, Italy
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Pinyon JL, von Jonquieres G, Crawford EN, Duxbury M, Al Abed A, Lovell NH, Klugmann M, Wise AK, Fallon JB, Shepherd RK, Birman CS, Lai W, McAlpine D, McMahon C, Carter PM, Enke YL, Patrick JF, Schilder AG, Marie C, Scherman D, Housley GD. Neurotrophin gene augmentation by electrotransfer to improve cochlear implant hearing outcomes. Hear Res 2019; 380:137-149. [DOI: 10.1016/j.heares.2019.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/07/2019] [Accepted: 06/12/2019] [Indexed: 12/14/2022]
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37
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Ma Y, Cortez-Jugo C, Li J, Lin Z, Richardson RT, Han Y, Zhou J, Björnmalm M, Feeney OM, Zhong QZ, Porter CJH, Wise AK, Caruso F. Engineering Biocoatings To Prolong Drug Release from Supraparticles. Biomacromolecules 2019; 20:3425-3434. [DOI: 10.1021/acs.biomac.9b00710] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Yutian Ma
- Bionics Institute, East Melbourne, Victoria 3002, Australia
| | | | | | | | | | | | | | - Mattias Björnmalm
- Bionics Institute, East Melbourne, Victoria 3002, Australia
- Department of Materials, Department of Bioengineering, and the Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Orlagh M. Feeney
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | | | - Christopher J. H. Porter
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Andrew K. Wise
- Bionics Institute, East Melbourne, Victoria 3002, Australia
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Carvalho CR, Silva-Correia J, Oliveira JM, Reis RL. Nanotechnology in peripheral nerve repair and reconstruction. Adv Drug Deliv Rev 2019; 148:308-343. [PMID: 30639255 DOI: 10.1016/j.addr.2019.01.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/20/2018] [Accepted: 01/05/2019] [Indexed: 02/07/2023]
Affiliation(s)
- Cristiana R Carvalho
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017, Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, AvePark, 4805-017 Barco, Guimarães, Portugal
| | - Joana Silva-Correia
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017, Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Joaquim M Oliveira
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017, Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, AvePark, 4805-017 Barco, Guimarães, Portugal
| | - Rui L Reis
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017, Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, AvePark, 4805-017 Barco, Guimarães, Portugal.
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39
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Ma Y, Wise AK, Shepherd RK, Richardson RT. New molecular therapies for the treatment of hearing loss. Pharmacol Ther 2019; 200:190-209. [PMID: 31075354 DOI: 10.1016/j.pharmthera.2019.05.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/02/2019] [Indexed: 12/11/2022]
Abstract
An estimated 466 million people suffer from hearing loss worldwide. Sensorineural hearing loss is characterized by degeneration of key structures of the sensory pathway in the cochlea such as the sensory hair cells, the primary auditory neurons and their synaptic connection to the hair cells - the ribbon synapse. Various strategies to protect or regenerate these sensory cells and structures are the subject of intensive research. Yet despite recent advances in our understandings of the capacity of the cochlea for repair and regeneration there are currently no pharmacological or biological interventions for hearing loss. Current research focusses on localized cochlear drug, gene and cell-based therapies. One of the more promising drug-based therapies is based on neurotrophic factors for the repair of the ribbon synapse after noise exposure, as well as preventing loss of primary auditory neurons and regrowth of the auditory neuron fibers after severe hearing loss. Drug therapy delivery technologies are being employed to address the specific needs of neurotrophin and other therapies for hearing loss that include the need for high doses, long-term delivery, localised or cell-specific targeting and techniques for their safe and efficacious delivery to the cochlea. Novel biomaterials are enabling high payloads of drugs to be administered to the cochlea with subsequent slow-release properties that are proving to be beneficial for treating hearing loss. In parallel, new gene therapy technologies are addressing the need for cell specificity and high efficacy for the treatment of both genetic and acquired hearing loss with promising reports of hearing recovery. Some biomaterials and cell therapies are being used in conjunction with the cochlear implant ensuring therapeutic benefit to the primary neurons during electrical stimulation. This review will introduce the auditory system, hearing loss and the potential for repair and regeneration in the cochlea. Drug delivery to the cochlea will then be reviewed, with a focus on new biomaterials, gene therapy technologies, cell therapy and the use of the cochlear implant as a vehicle for drug delivery. With the current pre-clinical research effort into therapies for hearing loss, including clinical trials for gene therapy, the future for the treatment for hearing loss is looking bright.
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Affiliation(s)
- Yutian Ma
- Bionics Institute, East Melbourne, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia; University of Melbourne, Department of Chemical Engineering, Parkville, Victoria, Australia
| | - Andrew K Wise
- Bionics Institute, East Melbourne, Australia; University of Melbourne, Medical Bionics Department, East Melbourne, Australia; University of Melbourne, Department of Surgery - Otolaryngology, East Melbourne, Australia
| | - Robert K Shepherd
- Bionics Institute, East Melbourne, Australia; University of Melbourne, Medical Bionics Department, East Melbourne, Australia; University of Melbourne, Department of Surgery - Otolaryngology, East Melbourne, Australia
| | - Rachael T Richardson
- Bionics Institute, East Melbourne, Australia; University of Melbourne, Medical Bionics Department, East Melbourne, Australia; University of Melbourne, Department of Surgery - Otolaryngology, East Melbourne, Australia.
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Shepherd RK, Carter PM, Enke YL, Wise AK, Fallon JB. Chronic intracochlear electrical stimulation at high charge densities results in platinum dissolution but not neural loss or functional changes in vivo. J Neural Eng 2019; 16:026009. [PMID: 30523828 PMCID: PMC8687872 DOI: 10.1088/1741-2552/aaf66b] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Although there are useful guidelines defining the boundary between damaging and non-damaging electrical stimulation they were derived from acute studies using large surface area electrodes in direct contact with cortical neurons. These parameters are a small subset of the parameters used by neural stimulators. More recently, histological examination of cochleae from patients that were long-term cochlear implant users have shown evidence of particulate platinum (Pt). The pathophysiological effect of Pt within the cochlea is unknown. We examined the response of the cochlea to stimulus levels beyond those regarded as safe, and to evaluate the pathophysiological response of the cochlea following chronic stimulation at charge densities designed to induce Pt corrosion in vivo. APPROACH 19 guinea pigs were systemically deafened and implanted with a cochlear electrode array containing eight Pt electrodes of 0.05, 0.075 or 0.2 mm2 area. Animals were electrically stimulated continuously for 28 d using charge balanced current pulses at charge densities of 400, 267 or 100 µC/cm2/phase. Electrically-evoked auditory brainstem responses (EABRs) were recorded to monitor neural function. On completion of stimulation electrodes were examined using scanning electron microscopy (SEM) and cochleae examined histology. Finally, analysis of Pt was measured using energy dispersive x-ray spectroscopy (EDS) and inductively coupled plasma mass spectrometry (ICP-MS). MAIN RESULTS Compared with unstimulated control electrodes and electrodes stimulated at 100 µC/cm2/phase, stimulation at 267 or 400 µC/cm2/phase resulted in significant Pt corrosion. Cochleae stimulated at these high charge densities contained particulate Pt. The extent of the foreign body response depended on the level of stimulation; cochleae stimulated at 267 or 400 µC/cm2/phase exhibited an extensive tissue response that included a focal region of necrosis close to the electrode. Despite chronic stimulation at high charge densities there was no loss of auditory neurons (ANs) in stimulated cochleae compared with their contralateral controls. Indeed, we report a statistically significant increase in AN density proximal to electrodes stimulated at 267 or 400 µC/cm2/phase. Finally, there was no evidence of a reduction in AN function associated with chronic stimulation at 100, 267 or 400 µC/cm2/phase as evidenced by stable EABR thresholds over the stimulation program. SIGNIFICANCE Chronic electrical stimulation of Pt electrodes at 267 or 400 µC/cm2/phase evoked a vigorous tissue response and produced Pt corrosion products that were located close to the electrode. Despite these changes at the electrode/tissue interface there was no evidence of neural loss or a reduction in neural function.
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Affiliation(s)
- Robert K Shepherd
- Bionics Institute, St Vincent's Hospital, Melbourne, Australia. Medical Bionics Department, The University of Melbourne, Melbourne, Australia
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41
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de Vries I, Schmitt H, Lenarz T, Prenzler N, Alvi S, Staecker H, Durisin M, Warnecke A. Detection of BDNF-Related Proteins in Human Perilymph in Patients With Hearing Loss. Front Neurosci 2019; 13:214. [PMID: 30971872 PMCID: PMC6445295 DOI: 10.3389/fnins.2019.00214] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/25/2019] [Indexed: 12/05/2022] Open
Abstract
The outcome of cochlear implantation depends on multiple variables including the underlying health of the cochlea. Brain derived neurotrophic factor (BDNF) has been shown to support spiral ganglion neurons and to improve implant function in animal models. Whether endogenous BDNF or BDNF-regulated proteins can be used as biomarkers to predict cochlear health and implant outcome has not been investigated yet. Gene expression of BDNF and downstream signaling molecules were identified in tissue of human cochleae obtained from normal hearing patients (n = 3) during skull base surgeries. Based on the gene expression data, bioinformatic analysis was utilized to predict the regulation of proteins by BDNF. The presence of proteins corresponding to these genes was investigated in perilymph (n = 41) obtained from hearing-impaired patients (n = 38) during cochlear implantation or skull base surgery for removal of vestibular schwannoma by nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS). Analyzed by mass spectrometry were 41 perilymph samples despite three patients undergoing bilateral cochlear implantation. These particular BDNF regulated proteins were not detectable in any of the perilymph samples. Subsequently, targeted analysis of the perilymph proteome data with Ingenuity Pathway Analysis (IPA) identified further proteins in human perilymph that could be regulated by BDNF. These BDNF regulated proteins were correlated to the presence of residual hearing (RH) prior to implantation and to the performance data with the cochlear implant after 1 year. There was overall a decreased level of expression of BDNF-regulated proteins in profoundly hearing-impaired patients compared to patients with some RH. Phospholipid transfer protein was positively correlated to the preoperative hearing level of the patients. Our data show that combination of gene expression arrays and bioinformatic analysis can aid in the prediction of downstream signaling proteins related to the BDNF pathway. Proteomic analysis of perilymph may help to identify the presence or absence of these molecules in the diseased organ. The impact of such prediction algorithms on diagnosis and treatment needs to be established in further studies.
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Affiliation(s)
- Ines de Vries
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany
| | - Heike Schmitt
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany.,Cluster of Excellence Hearing4all, German Research Foundation, Hannover Medical School, Hanover, Germany
| | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany.,Cluster of Excellence Hearing4all, German Research Foundation, Hannover Medical School, Hanover, Germany
| | - Nils Prenzler
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany
| | - Sameer Alvi
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, MO, United States
| | - Hinrich Staecker
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, MO, United States
| | - Martin Durisin
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany
| | - Athanasia Warnecke
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany.,Cluster of Excellence Hearing4all, German Research Foundation, Hannover Medical School, Hanover, Germany
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42
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Pharmacokinetics and tissue distribution of neurotrophin 3 after intracochlear delivery. J Control Release 2019; 299:53-63. [PMID: 30790594 DOI: 10.1016/j.jconrel.2019.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/11/2019] [Accepted: 02/15/2019] [Indexed: 01/22/2023]
Abstract
Neurotrophin therapy has potential to reverse some forms of hearing loss. However, cochlear pharmacokinetic studies are challenging due to small fluid volumes. Here a radioactive tracer was used to determine neurotrophin-3 retention, distribution and clearance after intracochlear administration. 125I-neurotrophin-3 was injected into guinea pig cochleae using a sealed injection technique comparing dosing volumes, rates and concentrations up to 750 μg/mL. Retention was measured by whole-cochlear gamma counts at five time points while distribution and clearance were assessed by autoradiography. Smaller injection volumes and higher concentrations correlated with higher retention of neurotrophin-3. Distribution of neurotrophin-3 was widespread throughout the cochlear tissue, decreasing in concentration from base to apex. Tissue distribution was non-uniform, with greatest density in cells lining the scala tympani and lower density in neural target tissue. The time constant for clearance of neurotrophin-3 from cochlear tissues was 38 h but neurotrophin-3 remained detectable for at least 2 weeks. Neurotrophin-3 was evident in the semi-circular canals with minor spread to the contralateral cochlea. This study is the first comprehensive evaluation of the disposition profile for a protein therapy in the cochlea. The findings and methods in this study will provide valuable guidance for the development of protein therapies for hearing loss.
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Hao J, Li SK. Inner ear drug delivery: Recent advances, challenges, and perspective. Eur J Pharm Sci 2019; 126:82-92. [DOI: 10.1016/j.ejps.2018.05.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/17/2018] [Accepted: 05/20/2018] [Indexed: 10/16/2022]
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Frisina RD, Budzevich M, Zhu X, Martinez GV, Walton JP, Borkholder DA. Animal model studies yield translational solutions for cochlear drug delivery. Hear Res 2018; 368:67-74. [PMID: 29793764 PMCID: PMC6165691 DOI: 10.1016/j.heares.2018.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/17/2018] [Accepted: 05/03/2018] [Indexed: 11/18/2022]
Abstract
The field of hearing and deafness research is about to enter an era where new cochlear drug delivery methodologies will become more innovative and plentiful. The present report provides a representative review of previous studies where efficacious results have been obtained with animal models, primarily rodents, for protection against acute hearing loss such as acoustic trauma due to noise overexposure, antibiotic use and cancer chemotherapies. These approaches were initiated using systemic injections or oral administrations of otoprotectants. Now, exciting new options for local drug delivery, which opens up the possibilities for utilization of novel otoprotective drugs or compounds that might not be suitable for systemic use, or might interfere with the efficacious actions of chemotherapeutic agents or antibiotics, are being developed. These include interesting use of nanoparticles (with or without magnetic field supplementation), hydrogels, cochlear micropumps, and new transtympanic injectable compounds, sometimes in combination with cochlear implants.
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Affiliation(s)
- R D Frisina
- Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Medical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA.
| | - M Budzevich
- Small Animal Imaging Lab, Moffitt Cancer Center, Tampa, FL, USA
| | - X Zhu
- Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Medical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| | - G V Martinez
- Small Animal Imaging Lab, Moffitt Cancer Center, Tampa, FL, USA
| | - J P Walton
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| | - D A Borkholder
- Microsystems Engineering, Rochester Institute of Technology, Rochester, NY, USA
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45
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Ma Y, Björnmalm M, Wise AK, Cortez-Jugo C, Revalor E, Ju Y, Feeney OM, Richardson RT, Hanssen E, Shepherd RK, Porter CJH, Caruso F. Gel-Mediated Electrospray Assembly of Silica Supraparticles for Sustained Drug Delivery. ACS APPLIED MATERIALS & INTERFACES 2018; 10:31019-31031. [PMID: 30192499 DOI: 10.1021/acsami.8b10415] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Supraparticles (SPs) composed of smaller colloidal particles provide a platform for the long-term, controlled release of therapeutics in biomedical applications. However, current synthesis methods used to achieve high drug loading and those involving biocompatible materials are often tedious and low throughput, thereby limiting the translation of SPs to diverse applications. Herein, we present a simple, effective, and automatable alginate-mediated electrospray technique for the assembly of robust spherical silica SPs (Si-SPs) for long-term (>4 months) drug delivery. The Si-SPs are composed of either porous or nonporous primary Si particles within a decomposable alginate matrix. The size and shape of the Si-SPs can be tailored by controlling the concentrations of alginate and silica primary particles used and key electrospraying parameters, such as flow rate, voltage, and collector distance. Furthermore, the performance (including drug loading kinetics, loading capacity, loading efficiency, and drug release) of the Si-SPs can be tuned by changing the porosity of the primary particles and through the retention or removal (via calcination) of the alginate matrix. The structure and morphology of the Si-SPs were characterized by electron microscopy, dynamic light scattering, N2 adsorption-desorption analysis, and X-ray photoelectron spectroscopy. The cytotoxicity and degradability of the Si-SPs were also examined. Drug loading kinetics and loading capacity for six different types of Si-SPs, using a model protein drug (fluorescently labeled lysozyme), demonstrate that Si-SPs prepared from primary silica particles with large pores can load significant amounts of lysozyme (∼10 μg per SP) and exhibit sustained, long-term release of more than 150 days. Our experiments show that Si-SPs can be produced through a gel-mediated electrospray technique that is robust and automatable (important for clinical translation and commercialization) and that they present a promising platform for long-term drug delivery.
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Affiliation(s)
| | - Mattias Björnmalm
- Bionics Institute , East Melbourne , Victoria 3002 , Australia
- Department of Materials, Department of Bioengineering, and the Institute of Biomedical Engineering , Imperial College London , London SW7 2AZ , U.K
| | - Andrew K Wise
- Bionics Institute , East Melbourne , Victoria 3002 , Australia
| | | | | | | | - Orlagh M Feeney
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and Drug Delivery Disposition and Dynamics , Monash Institute of Pharmaceutical Sciences, Monash University , Parkville , Victoria 3052 , Australia
| | | | - Eric Hanssen
- Melbourne Advanced Microscopy Facility and Department of Biochemistry and Molecular Biology , Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Parkville , Victoria 3010 , Australia
| | | | - Christopher J H Porter
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and Drug Delivery Disposition and Dynamics , Monash Institute of Pharmaceutical Sciences, Monash University , Parkville , Victoria 3052 , Australia
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46
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Salt AN, Hirose K. Communication pathways to and from the inner ear and their contributions to drug delivery. Hear Res 2018; 362:25-37. [PMID: 29277248 PMCID: PMC5911243 DOI: 10.1016/j.heares.2017.12.010] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 11/08/2017] [Accepted: 12/05/2017] [Indexed: 01/04/2023]
Abstract
The environment of the inner ear is highly regulated in a manner that some solutes are permitted to enter while others are excluded or transported out. Drug therapies targeting the sensory and supporting cells of the auditory and vestibular systems require the agent to gain entry to the fluid spaces of the inner ear, perilymph or endolymph, which surround the sensory organs. Access to the inner ear fluids from the vasculature is limited by the blood-labyrinth barriers, which include the blood-perilymph and blood-strial barriers. Intratympanic applications provide an alternative approach in which drugs are applied locally. Drug from the applied solution enters perilymph through the round window membrane, through the stapes, and under some circumstances, through thin bone in the otic capsule. The amount of drug applied to the middle ear is always substantially more than the amount entering perilymph. As a result, significant amounts of the applied drug can pass to the digestive system, to the vasculature, and to the brain. Drugs in perilymph pass to the vasculature and to cerebrospinal fluid via the cochlear aqueduct. Conversely, drugs applied to cerebrospinal fluid, including those given intrathecally, can enter perilymph through the cochlear aqueduct. Other possible routes in or out of the ear include passage by neuronal pathways, passage via endolymph and the endolymphatic sac, and possibly via lymphatic pathways. A better understanding of the pathways for drug movements in and out of the ear will enable better intervention strategies.
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Affiliation(s)
- Alec N Salt
- Department of Otolaryngology, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, MO, USA.
| | - Keiko Hirose
- Department of Otolaryngology, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, MO, USA
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Aijie C, Xuan L, Huimin L, Yanli Z, Yiyuan K, Yuqing L, Longquan S. Nanoscaffolds in promoting regeneration of the peripheral nervous system. Nanomedicine (Lond) 2018; 13:1067-1085. [PMID: 29790811 DOI: 10.2217/nnm-2017-0389] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The ability to surgically repair peripheral nerve injuries is urgently needed. However, traditional tissue engineering techniques, such as autologous nerve transplantation, have some limitations. Therefore, tissue engineered autologous nerve grafts have become a suitable choice for nerve repair. Novel tissue engineering techniques derived from nanostructured conduits have been shown to be superior to other successful functional neurological structures with different scaffolds in terms of providing the required structures and properties. Additionally, different biomaterials and growth factors have been added to nerve scaffolds to produce unique biological effects that promote nerve regeneration and functional recovery. This review summarizes the application of different nanoscaffolds in peripheral nerve repair and further analyzes how the nanoscaffolds promote peripheral nerve regeneration.
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Affiliation(s)
- Chen Aijie
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
- Guangdong Provincial Key Laboratory of Construction & Detection in Tissue Engineering, Guangzhou 510515, China
| | - Lai Xuan
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
| | - Liang Huimin
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
| | - Zhang Yanli
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
| | - Kang Yiyuan
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
| | - Lin Yuqing
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
| | - Shao Longquan
- Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, Guangdong 510515, China
- Guangdong Provincial Key Laboratory of Construction & Detection in Tissue Engineering, Guangzhou 510515, China
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Schmidt N, Schulze J, Warwas DP, Ehlert N, Lenarz T, Warnecke A, Behrens P. Long-term delivery of brain-derived neurotrophic factor (BDNF) from nanoporous silica nanoparticles improves the survival of spiral ganglion neurons in vitro. PLoS One 2018; 13:e0194778. [PMID: 29584754 PMCID: PMC5870973 DOI: 10.1371/journal.pone.0194778] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/11/2018] [Indexed: 11/18/2022] Open
Abstract
Sensorineural hearing loss (SNHL) can be overcome by electrical stimulation of spiral ganglion neurons (SGNs) via a cochlear implant (CI). Restricted CI performance results from the spatial gap between the SGNs and the electrode, but the efficacy of CI is also limited by the degeneration of SGNs as one consequence of SHNL. In the healthy cochlea, the survival of SGNs is assured by endogenous neurotrophic support. Several applications of exogenous neurotrophic supply have been shown to reduce SGN degeneration in vitro and in vivo. In the present study, nanoporous silica nanoparticles (NPSNPs), with an approximate diameter of <100 nm, were loaded with the brain-derived neurotrophic factor (BDNF) to test their efficacy as long-term delivery system for neurotrophins. The neurotrophic factor was released constantly from the NPSNPs over a release period of 80 days when the surface of the nanoparticles had been modified with amino groups. Cell culture investigations with NIH3T3 fibroblasts attest a good general cytocompatibility of the NPSNPs. In vitro experiments with SGNs indicate a significantly higher survival rate of SGNs in cell cultures that contained BDNF-loaded nanoparticles compared to the control culture with unloaded NPSNPs (p<0.001). Importantly, also the amounts of BDNF released up to a time period of 39 days increased the survival rate of SGNs. Thus, NPSNPs carrying BDNF are suitable for the treatment of inner ear disease and for the protection and the support of SGNs. Their nanoscale nature and the fact that a direct contact of the nanoparticles and the SGNs is not necessary for neuroprotective effects, should allow for the facile preparation of nanocomposites, e.g., with biocompatible polymers, to install coatings on implants for the realization of implant-based growth factor delivery systems.
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Affiliation(s)
- Nadeschda Schmidt
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Jennifer Schulze
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Dawid P. Warwas
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
| | - Nina Ehlert
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Thomas Lenarz
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Peter Behrens
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
- * E-mail:
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Pharmacokinetic principles in the inner ear: Influence of drug properties on intratympanic applications. Hear Res 2018; 368:28-40. [PMID: 29551306 DOI: 10.1016/j.heares.2018.03.002] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/06/2018] [Accepted: 03/02/2018] [Indexed: 01/12/2023]
Abstract
Local drug delivery to the ear has gained wide clinical acceptance, with the choice of drug and application protocol in humans largely empirically-derived. Here, we review the pharmacokinetics underlying local therapy of the ear using the drugs commonly used in clinical practice as examples. Based on molecular properties and perilymph measurements interpreted through computer simulations we now better understand the principles underlying entry and distribution of these and other drugs in the ear. From our analysis, we have determined that dexamethasone-phosphate, a pro-drug widely-used clinically, has molecular and pharmacokinetic properties that make it ill-suited for use as a local therapy for hearing disorders. This polar form of dexamethasone, used as a more soluble agent in intravenous preparations, passes less readily through lipid membranes, such as those of the epithelia restricting entry at the round window membrane and stapes. Once within the inner ear, dexamethasone-phosphate is cleaved to the active form, dexamethasone, which is less polar, passes more readily through lipid membranes of the blood-perilymph barrier and is rapidly eliminated from perilymph without distributing to apical cochlear regions. Dexamethasone-phosphate therefore provides only a brief exposure of the basal regions of the cochlea to active drug. Other steroids, such as triamcinolone-acetonide, exhibit pharmacokinetic properties more appropriate to the ear and merit more detailed consideration.
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Nanomedicine for Inner Ear Diseases: A Review of Recent In Vivo Studies. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3098230. [PMID: 29130038 PMCID: PMC5654248 DOI: 10.1155/2017/3098230] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/30/2017] [Indexed: 02/04/2023]
Abstract
Nanoparticles are promising therapeutic options for inner ear disease. In this report, we review in vivo animal studies in the otologic field using nanoparticles over the past 5 years. Many studies have used nanoparticles to deliver drugs, genes, and growth factors, and functional and morphological changes have been observed. The constituents of nanoparticles are also diversifying into various biocompatible materials, including poly(lactic-co-glycolic acid) (PLGA). The safe and effective delivery of drugs or genes in the inner ear will be a breakthrough for the treatment of inner ear diseases, including age-related hearing loss.
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