Safety, reliability, and operability of cochlear implant electrode arrays coated with biocompatible polymer

Abstract

Under light and scanning electron microscopy, polymer-coated electrodes did not appear different from uncoated electrodes, and no change was observed after mechanical stressing of the arrays. Electrode insertion was significantly easier when polymer-coated electrodes were used. Auditory brainstem response (ABR) thresholds did not differ between groups, but p1-n1 amplitudes of the coated group were larger compared with the uncoated group at 32 kHz at 28 days after surgery. The survival of outer hair cells and spiral ganglion cells was significantly greater in the polymer-coated group.

A PLLA Coating Does Not Affect the Insertion Pressure or Frictional Behavior of a CI Electrode Array at Higher Insertion Speeds

“…While most of the known coatings for the CI electrode array tend to be made of hydrogel composites [33,34] or biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer [32], this is the first time that a PLLA coating has been used, which is well established in biomedical applications, such as in cardiovascular systems [43]. Here, a layer thickness of 10 µm was selected to ensure a sufficient surface area for future drug delivery while taking into account the small diameter of the vulnerable scala tympani.…”

“…These agents are mainly glycocorticoids, which are administered locally or systemically [26][27][28]. A wide variety of systems are used to inhibit insertion trauma or to deliver drugs directly into the cochlea, such as intraoperative administration using catheters, longer-acting pump systems, or drug depots either in the silicone of the electrode array or in separate coatings [24][25][26][27][28][29][30][31][32][33][34]. The effect of polymer coatings without drug loading was tested by Hadler et al [29].…”

The impact of round window vs cochleostomy surgical approaches on interscalar excursions in the cochlea: Preliminary results from a flat‐panel computed tomography study

“… 5 , 10 , 11 In fact, there is evidence that suggests a strong association between interscalar excursion and loss of residual hearing following cochlear implantation. 12 Consequentially, the interest and popularity in refining surgical approaches to reduce surgically-induced trauma has been growing exponentially each year: recent studies are finding roles for image-guided CI insertions, 13 biocompatible polymer-coated electrode arrays, 14 and new atraumatic electrode designs. While these new surgical tools and options in device design are relatively elective to the operation, insertion of the electrode array is arguably the most important step in this surgical operation.…”

“…surgical approaches to reduce surgically-induced trauma has been growing exponentially each year: recent studies are finding roles for image-guided CI insertions, 13 biocompatible polymer-coated electrode arrays, 14 and new atraumatic electrode designs. While these new surgical tools and options in device design are relatively elective to the operation, insertion of the electrode array is arguably the most important step in this surgical operation.…”

Synergistic Effects of Ions and Surface Potentials on Antifouling Poly(3,4-ethylenedioxythiophene): Comparison of Oligo(Ethylene Glycol) and Phosphorylcholine

“…Antifouling surfaces that resist nonspecific binding of proteins and cells play a major role in various biomedical engineering applications − such as medical implants, , biosensors, , bioelectronics, cell capturing devices, and drug delivery carriers. − Moreover, reducing biofouling of implanted devices can prevent adverse inflammatory responses and injuries in the area of tissue engineering . Nonspecific adhesion of proteins, bacteria, and platelets continues to bedevil the utilization of long-term implanted bioelectronics because of the uncontrolled accumulation of biofouling agents, which causes device malfunctions.…”