A PLLA Coating does not Affect Insertion Pressure and Frictional Behavior of CI Electrode Array at Higher Insertion Speeds

To prevent endocochlear insertion trauma, the development of drug-releasing coatings in the field of CI electrodes is increasingly becoming the focus of research. The influence of a poly-L-lactide (PLLA) coated electrode array on the two mechanical parameters "insertion pressure" and "insertion friction" has not been sufficiently investigated so far. The aim of this study is (I) to measure the insertion pressure and (II) to record the friction coefficient of a, 31.5 mm long, PLLA-coated electrode array. At different insertion speeds (0.1, 0.5, 1.0 1.5, and 2.0 mm/s), the insertion pressure is measured in a linear cochlear model; the friction coefficient is determined on porcine fascia simulating the endocochlear lining. Uncoated electrode arrays serve as a comparison group. It was shown that both the maximum insertion pressure and the friction coefficient of a PLLA-coated electrode generated in the linear model do not depend on the insertion speed. Moreover, it was found that from higher insertion speeds (1.0 mm/s and higher), the insertion pressure (1.268  ± 0.032 mmHg) and the friction coefficient (0.40  ± 0.15) of a coated electrode array are similar to those of an uncoated one (1.252  ± 0.034 mmHg and 0.36  ± 0.15). Consequently, PLLA as a coating does not significantly affect the insertion pressure and insertion friction of a CI electrode array when higher insertion speeds are used. Therefore, PLLA is a suitable material for coating CI electrode arrays and can be considered as a potential material for an agent-releasing system.

Publication History

Article published online:
24 May 2022