Preparation, characterization and application research of a sustained dexamethasone releasing electrode coating for cochlear implantation

Xu, Muqing; Ma, Dong; Chen, Dongxiu; Cai, Jun; He, Qiaofang; Shu, Fan; Tang, Jie; Zhang, Hongzheng

doi:10.1016/j.msec.2018.04.033

Cited by 18 publications

(14 citation statements)

References 43 publications

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“…Drug elution from the cochlear implant has been explored previously using a mini-osmotic pump or drug loaded in a gel surrounding the implant (Mamelle et al, 2017;Xu et al, 2018). Other reported drug delivery systems are not able to achieve long-term continuous administration or maintain a therapeutic level of drug concentration for a long time.…”

Section: Discussionmentioning

confidence: 99%

Long-Term Release of Dexamethasone With a Polycaprolactone-Coated Electrode Alleviates Fibrosis in Cochlear Implantation

Chen

Luo

Pan

et al. 2021

Front. Cell Dev. Biol.

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Cochlear implantation (CI) is the major treatment for severe sensorineural hearing loss. However, the fibrotic tissue forming around the electrodes reduces the treatment effectiveness of CI. Dexamethasone (DEX) is usually applied routinely in perioperative treatment of cochlear implantation (CI), but its diffusion in the inner ear after systemic administration is limited. In the present study, an electrode coated with polycaprolactone (PCL) loaded with dexamethasone was developed with a simple preparation process to maintain the stability of the electrode itself. The DEX-loaded PCL coating has good biocompatibility and does not change the smoothness, flexibility, or compliance of the implant electrode. Stable and effective DEX concentrations were maintained for more than 9 months. Compared with the pristine electrode, decreasing intracochlear fibrosis, protection of hair cells and spiral ganglion cells, and better residual hearing were observed 5 weeks after PCL-DEX electrode implantation. The PCL-DEX electrode has great potential in preventing hearing loss and fibrosis by regulating macrophages and inhibiting the expression of the fibrosis-related factors IL-1β, TNF-α, IL-4, and TGF-β1. In conclusion, the PCL-DEX electrode coating shows promising application in CI surgery.

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Section: Discussionmentioning

confidence: 99%

Long-Term Release of Dexamethasone With a Polycaprolactone-Coated Electrode Alleviates Fibrosis in Cochlear Implantation

Chen

Luo

Pan

et al. 2021

Front. Cell Dev. Biol.

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“…Currently, there are several approaches under investigation to reduce trauma and the formation of fibrous tissue after cochlear implantation. Amongst them are surface patterning of the electrode array [8], application of drugs via pumps [9], cells [10], coatings [11], or from a reservoir, such as the silicone of the electrode array [12,13], as well as intraoperative deposition of steroids either directly [6] or by using a catheter [14]. To the best of our knowledge, besides one report on three patients receiving mononuclear cells obtained from bone marrow with the cochlear implant [10], only intraoperative deposition of steroids and steroid elution from the silicone of CI electrodes have been used clinically so far [12,14] and were shown to reduce or delay the impedance increase after implantation.…”

Section: Introductionmentioning

confidence: 99%

PLLA Coating of Active Implants for Dual Drug Release

et al. 2022

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Cochlear implants, like other active implants, rely on precise and effective electrical stimulation of the target tissue but become encapsulated by different amounts of fibrous tissue. The current study aimed at the development of a dual drug release from a PLLA coating and from the bulk material to address short-term and long-lasting release of anti-inflammatory drugs. Inner-ear cytocompatibility of drugs was studied in vitro. A PLLA coating (containing diclofenac) of medical-grade silicone (containing 5% dexamethasone) was developed and release profiles were determined. The influence of different coating thicknesses (2.5, 5 and 10 µm) and loadings (10% and 20% diclofenac) on impedances of electrical contacts were measured with and without pulsatile electrical stimulation. Diclofenac can be applied to the inner ear at concentrations of or below 4 × 10−5 mol/L. Release of dexamethasone from the silicone is diminished by surface coating but not blocked. Addition of 20% diclofenac enhances the dexamethasone release again. All PLLA coatings serve as insulator. This can be overcome by using removable masking on the contacts during the coating process. Dual drug release with different kinetics can be realized by adding drug-loaded coatings to drug-loaded silicone arrays without compromising electrical stimulation.

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“…44,45 To this end, applications of nanogenerators 51 primarily include wearable and implantable sensing equipment, [52][53][54] capsule endoscopes, 55,56 cardiac pacemakers, [57][58][59] artificial hearts, 60 spinal cord electrical stimulators, [61][62][63] and artificial cochleae. [64][65][66] Providing safe, convenient, efficient, and reliable power supply for biomedical sensors and implantable electronic devices is one of the most critical problems. Traditional contact-based electric energy transmission via wires is prone to wear and exposure over the long term, which soon leads to accidental contact and electric shock, posing a significant potential safety hazard.…”

Section: Introductionmentioning

confidence: 99%

Applications of nanogenerators for biomedical engineering and healthcare systems

Wang

Pang

et al. 2021

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Preparation, characterization and application research of a sustained dexamethasone releasing electrode coating for cochlear implantation

Cited by 18 publications

References 43 publications

Long-Term Release of Dexamethasone With a Polycaprolactone-Coated Electrode Alleviates Fibrosis in Cochlear Implantation

Long-Term Release of Dexamethasone With a Polycaprolactone-Coated Electrode Alleviates Fibrosis in Cochlear Implantation

PLLA Coating of Active Implants for Dual Drug Release

Applications of nanogenerators for biomedical engineering and healthcare systems

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