A novel silk-based vocal fold augmentation material: 6-month evaluation in a canine model

Area of Science:

• Biomaterials Science
• Otolaryngology
• Regenerative Medicine

Background:

• Vocal fold augmentation requires biocompatible, injectable materials for long-term efficacy and site retention.
• A novel silk protein particle suspended in hyaluronic acid (Silk-HA) was developed for vocal fold augmentation.

Purpose of the Study:

• To evaluate the 6-month preclinical findings of Silk-HA vocal fold injections in a canine model.
• To compare the longevity, immune response, and migration of Silk-HA versus calcium hydroxylapatite in carboxymethyl cellulose (CaHA-CMC).

Main Methods:

• Twelve beagle dogs received transoral injections of Silk-HA or CaHA-CMC into the thyroarytenoid muscles.
• Materials were delivered via custom catheter (Silk-HA) or commercial needle (CaHA-CMC).
• Animals were sacrificed at 6 months for analysis of implant longevity, immune response, and migration.

Main Results:

• Silk-HA provided immediate vocal fold medialization lasting at least 6 months.
• Both Silk-HA and CaHA-CMC elicited similar inflammatory responses.
• Silk-HA showed no migration, while CaHA-CMC migrated in 4/6 canines, including to lymph nodes in 2/6.

Conclusions:

• Silk-HA demonstrates favorable longevity and immune response compared to CaHA-CMC in a canine model.
• The absence of Silk-HA migration suggests significant potential for clinical vocal fold injection applications.