Vocal Fold Scar Treatment via Controlled Dexamethasone Delivery With a Light-Activatable Implant

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Regenerative Medicine

Background:

• Intralesional steroid injections for vocal fold (VF) scarring have limited efficacy due to rapid clearance.
• Developing sustained drug delivery systems is crucial for effective VF scar treatment.

Purpose of the Study:

• To evaluate the efficacy of a light-activatable dexamethasone implant compared to a single steroid injection for vocal fold scar healing.
• To assess the impact of the implant on VF biomechanics and vibratory behavior.

Main Methods:

• Ten rabbits underwent endoscopic VF injury and were treated with either a dexamethasone injection or a light-activatable implant.
• Implants were activated with a near-infrared laser on days 0 and 21.
• Vocal fold vibrations, normal force, stiffness, and displacement were analyzed using high-speed video and kymography after 42 days.

Main Results:

• Implant-treated VFs showed significantly reduced normal force and stiffness, and increased displacement compared to injury-only VFs.
• Implant-treated VFs exhibited improved vibratory behavior (larger amplitude ratios) and tissue architecture.
• No significant quantitative differences were found between the implant-treated and injection-treated groups.

Conclusions:

• A light-activatable dexamethasone implant effectively improved VF biomechanics, vibratory function, and histological outcomes in a rabbit model.
• This novel approach provides controlled and repeatable therapy for vocal fold scars.
• The light-activatable implant demonstrates potential as an alternative to conventional steroid injections for VF scar management.