Figure 2

Experimental equipment and study design. (A) For the in vitro study, an identical number of HEI-OC1 cells was cultured with H₂O₂ and different concentrations of SL. After 24 h, cell viability was assessed using CCK-8 assays. For drug delivery, osmotic pumps with different capacities (1004 and 2004 pumps) (B and C) were used. The pumps were connected to a microcatheter (D) to deliver the pharmacological agent to the target tissue. Photograph of surgical procedures (E) showing the implanted dummy electrode through the round window with exposure of the cochlea by removing the bony wall of bullae. A schematic of the study design is presented at the bottom. (F) A image of ‘dummy implant’ is shown. (G) Auditory brainstem responses were measured four times to determine the threshold: preoperatively and 1, 7, and 30 days postoperatively. RT-PCR was performed at 7 and 30 days after the operation. The histological analysis was performed 30 days after the operation.