Multicargo Porous Cochlear Electrode Coating for Antifibrosis After Cochlear Implantation

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Otolaryngology

Background:

• Sensorineural hearing loss significantly impairs communication and cognition.
• Cochlear implantation (CI) is effective but can harm inner ear structures due to poor biocompatibility and fibrosis.
• Developing protective strategies for CI is crucial for preserving residual hearing and neural function.

Purpose of the Study:

• To develop and evaluate a novel porous methacrylated poly(dimethylsiloxane) (MA-PDMS)-coated cochlear electrode.
• To incorporate a hybrid hydrogel system with dexamethasone sodium phosphate (Dex), Ti3C2Tx MXene (MXene), and methacrylate gelatin (GelMA) for drug delivery and biocompatibility.
• To assess the protective effects of the coating on inner ear cells and residual hearing in vivo.

Main Methods:

• Fabrication of a porous MA-PDMS coating for cochlear electrodes.
• Formulation of a hybrid hydrogel incorporating Dex, MXene, and GelMA within the porous coating.
• In vitro assessment of biocompatibility, drug loading, and release kinetics.
• In vivo evaluation of hair cell and spiral ganglion neuron protection, residual hearing preservation, and fibrosis reduction.

Main Results:

• The MA-PDMS coating demonstrated excellent biocompatibility and drug delivery capabilities in vitro.
• The hybrid hydrogel coating effectively protected hair cells and spiral ganglion neurons.
• Significant preservation of residual hearing and reduction in fibrosis were observed in vivo.
• The coating showed good drug loading and release capacity.

Conclusions:

• The developed porous electrode coating offers a promising strategy for enhancing CI outcomes.
• This approach mitigates damage to inner ear structures and preserves residual hearing.
• The drug-eluting, biocompatible coating represents a valuable advancement for cochlear electrode transplantation.