Nanoporous Silica Embedded in Nanoporous Platinum: A Versatile Composite Coating for Implant‐Associated Drug Delivery From Neuronal Electrodes

ABSTRACT Sensorineural hearing loss, resulting from damage to the hair cells of the inner ear, profoundly impairs quality of life. A widely used treatment involves cochlear implants (CIs), which electrically stimulate the remaining spiral ganglion neurons (SGNs) to partially restore auditory function. Despite considerable technological progress, improvements in implant performance are necessary. Local and controlled drug delivery represents a promising strategy to optimize the implant's biological environment and to support the preservation of SGNs. This study introduces a patented implant‐associated local drug delivery system, designed as a nanocomposite coating for electrode contacts. The composite consists of nanoporous silica nanoparticles embedded within nanoporous platinum synthesized via electrochemical deposition combined with templating techniques, resulting in a homogeneous and mechanically robust coating. The porous structure enhances electrochemical performance by increasing the specific surface area, while simultaneously improving drug loading capacity and enabling dexamethasone release. Cytocompatibility tests using fibroblasts and SGNs indicate good cytocompatibility, supporting its suitability for CI applications. Furthermore, reduced TNF‐α levels in stressed dendritic cells following exposure to released dexamethasone suggest a potential anti‐inflammatory effect and provide an initial proof‐of‐concept for the biological functionality. Ultimately, these features suggest that the proposed system may contribute to improved hearing outcomes in CI recipients.