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Hong MK, Echanique KA, Hoffman LF, Kita AE. Designing a Prolonged Method of Therapeutic Delivery to Support Rehabilitation From Ototoxic Damage in a Schwann Cell Model. Otol Neurotol 2023; 44:373-381. [PMID: 36791364 PMCID: PMC10038897 DOI: 10.1097/mao.0000000000003839] [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] [Indexed: 02/17/2023]
Abstract
HYPOTHESIS The ototoxicity of gentamicin and cisplatin can be evaluated with a Schwann cell model to screen for otoprotective agents that can be encapsulated into poly (lactic-co-glycolic acid) (PLGA) microparticles for drug delivery to the inner ear. BACKGROUND Aminoglycosides and cisplatin are widely prescribed but known to cause ototoxicity. There is strong evidence that compromise to Schwann cells ensheathing inner ear afferent neurons results in inner ear dysfunction mimicking drug-induced ototoxicity. There is a need for a model for ototoxic demyelination to screen medications for protective potential and to subsequently target and tune the delivery of any promising agents. METHODS RT4-D6P2T rat schwannoma cells were used as a Schwann cell model to assess gentamicin and cisplatin toxicity and to screen for protective agents. Cell viability was evaluated with the MTT cell proliferation assay. N -acetylcysteine (NAC) was encapsulated into a PLGA microparticle, and its elution profile was determined. RESULTS The estimated 50% lethal concentration dose for gentamicin was 805.6 μM, which was 46-fold higher than that for cisplatin (17.5 μM). In several trials, cells dosed with NAC and cisplatin demonstrated a 22.6% ( p < 0.001) increase in cell viability when compared with cisplatin alone. However, this protective effect was not consistent across all trials. NAC was encapsulated into a PLGA microparticle and elution plateaued at 5 days. CONCLUSION When dosed at their respective therapeutic ranges, cisplatin is more likely than gentamicin to induce damage to the Schwann cell model. Although NAC demonstrates an uncertain role in protecting against cisplatin-induced Schwann cell cytotoxicity, this study establishes a method to screen for other otoprotective medications to encapsulate into a tunable microparticle for localized drug delivery.
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Affiliation(s)
- Michelle K Hong
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
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Electrospun nanofibrous membrane for biomedical application. SN APPLIED SCIENCES 2022; 4:172. [PMID: 35582285 PMCID: PMC9099337 DOI: 10.1007/s42452-022-05056-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 05/02/2022] [Indexed: 11/09/2022] Open
Abstract
Electrospinning is a simple, cost-effective, flexible, and feasible continuous micro-nano polymer fiber preparation technology that has attracted extensive scientific and industrial interest over the past few decades, owing to its versatility and ability to manufacture highly tunable nanofiber networks. Nanofiber membrane materials prepared using electrospinning have excellent properties suitable for biomedical applications, such as a high specific surface area, strong plasticity, and the ability to manipulate their nanofiber components to obtain the desired properties and functions. With the increasing popularity of nanomaterials in this century, electrospun nanofiber membranes are gradually becoming widely used in various medical fields. Here, the research progress of electrospun nanofiber membrane materials is reviewed, including the basic electrospinning process and the development of the materials as well as their biomedical applications. The main purpose of this review is to discuss the latest research progress on electrospun nanofiber membrane materials and the various new electrospinning technologies that have emerged in recent years for various applications in the medical field. The application of electrospun nanofiber membrane materials in recent years in tissue engineering, wound dressing, cancer diagnosis and treatment, medical protective equipment, and other fields is the main topic of discussion in this review. Finally, the development of electrospun nanofiber membrane materials in the biomedical field is systematically summarized and prospects are discussed. In general, electrospinning has profound prospects in biomedical applications, as it is a practical and flexible technology used for the fabrication of microfibers and nanofibers. This review summarizes recent research on the application of electrospun nanofiber membranes as tissue engineering materials for the cardiovascular system, motor system, nervous system, and other clinical aspects. Research on the application of electrospun nanofiber membrane materials as protective products is discussed in the context of the current epidemic situation. Examples and analyses of recent popular applications in tissue engineering, wound dressing, protective products, and cancer sensors are presented.
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Chemotherapy-induced hearing loss: the applications of bio-nanotechnologies and bile acid-based delivery matrices. Ther Deliv 2021; 12:723-737. [PMID: 34697955 DOI: 10.4155/tde-2021-0050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Advancement in the prevention of chemotherapy-induced hearing loss has proposed new nano-based delivery matrices that can target inner ear regions most damaged by chemotherapy. Chemotherapy agents (e.g., cisplatin) induce increased reactive oxygen species formation in the inner ear that damage sensory hair cells and result in irreversible hearing impairment. Exogenous antioxidants (e.g., Probucol and metformin) have been shown to block the formation of these reactive oxygen species. Delivery of these drugs in effective concentrations remains a challenge. Microencapsulation in combination with drug excipients provides one technique to effectively deliver these drugs. This paper investigates the use of probucol and metformin in combination with drug excipients for novel, inner ear, delivery.
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Qnouch A, Solarczyk V, Verin J, Tourrel G, Stahl P, Danede F, Willart JF, Lemesre PE, Vincent C, Siepmann J, Siepmann F. Dexamethasone-loaded cochlear implants: How to provide a desired "burst release". INTERNATIONAL JOURNAL OF PHARMACEUTICS-X 2021; 3:100088. [PMID: 34553137 PMCID: PMC8441626 DOI: 10.1016/j.ijpx.2021.100088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 06/03/2021] [Accepted: 06/06/2021] [Indexed: 12/20/2022]
Abstract
Cochlear implants containing iridium platinum electrodes are used to transmit electrical signals into the inner ear of patients suffering from severe or profound deafness without valuable benefit from conventional hearing aids. However, their placement is invasive and can cause trauma as well as local inflammation, harming remaining hair cells or other inner ear cells. As foreign bodies, the implants also induce fibrosis, resulting in a less efficient conduction of the electrical signals and, thus, potentially decreased system performance. To overcome these obstacles, dexamethasone has recently been embedded in this type of implants: into the silicone matrices separating the metal electrodes (to avoid short circuits). It has been shown that the resulting drug release can be controlled over several years. Importantly, the dexamethasone does not only act against the immediate consequences of trauma, inflammation and fibrosis, it can also be expected to be beneficial for remaining hair cells in the long term. However, the reported amounts of drug released at “early” time points (during the first days/weeks) are relatively low and the in vivo efficacy in animal models was reported to be non-optimal. The aim of this study was to increase the initial “burst release” from the implants, adding a freely water-soluble salt of a phosphate ester of dexamethasone. The idea was to facilitate water penetration into the highly hydrophobic system and, thus, to promote drug dissolution and diffusion. This approach was efficient: Adding up to 10% dexamethasone sodium phosphate to the silicone matrices substantially increased the resulting drug release rate at early time points. This can be expected to improve drug action and implant functionality. But at elevated dexamethasone sodium phosphate loadings device swelling became important. Since the cochlea is a tiny and sensitive organ, a potential increase in implant dimensions over time must be limited. Hence, a balance has to be found between drug release and implant swelling.
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Affiliation(s)
- A Qnouch
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - V Solarczyk
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Verin
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - G Tourrel
- Oticon Medical, R&D, 06224 Vallauris, France
| | - P Stahl
- Oticon Medical, R&D, 06224 Vallauris, France
| | - F Danede
- Univ. Lille, UMR CNRS 8207, UMET, F-59655 Villeneuve d'Ascq, France
| | - J F Willart
- Univ. Lille, UMR CNRS 8207, UMET, F-59655 Villeneuve d'Ascq, France
| | - P E Lemesre
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - C Vincent
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - F Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
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Lehner E, Liebau A, Syrowatka F, Knolle W, Plontke SK, Mäder K. Novel biodegradable Round Window Disks for inner ear delivery of dexamethasone. Int J Pharm 2020; 594:120180. [PMID: 33338566 DOI: 10.1016/j.ijpharm.2020.120180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/20/2022]
Abstract
Drug delivery to the inner ear is an important and very challenging field. The cochlea is protected by several barriers that need to be overcome in the drug delivery process. Local drug delivery can avoid undesirable side effects arising from systemic drug delivery. We developed a biodegradable dexamethasone-loaded Round Window (RW) Disk based on poly(D,L-lactic-co-glycolic acid) (PLGA) for local drug therapy to the inner ear by RW membrane administration by a film-casting method. The optimal drying time was characterized by thermogravimetric analysis and differential scanning calorimetry. In addition, the mass and polymer degradation over time of drug release was measured in vitro showing a total mass loss of 70% after 3 weeks. Dexamethasone release was determined by a RW model setup using a polyethylene terephthalate membrane. We achieved a controlled release over 52 days. Ex vivo implantation of a RW Disk onto a guinea pig RW membrane indicated well-fitting properties of the drug delivery device leading to a close surface contact with the membrane and the successful proof of concept. The developed RW Disks could be new and promising drug delivery device to achieve effective local drug delivery to the inner ear for an extended time.
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Affiliation(s)
- E Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - A Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - F Syrowatka
- Interdisciplinary Center of Materials Science, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - W Knolle
- Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany
| | - S K Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - K Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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