Self-Healing and Adhesive Artificial Tissue Implant for Voice Recovery

Loss of voice after vocal fold resection due to laryngeal cancer is a significant problem resulting in a low quality of life. Although there were many attempts to achieve a functional restoration of voice, challenges to regenerate vocal fold still remain due to its unique tissue mechanical characteristics such as pliability that produces phonation via vibration. In this study, we developed a mechanically compliant interpenetrating polymer network (IPN) hydrogel based on polyacrylamide (PAAM) and gelatin that matches physical and functional properties with native vocal fold tissue. The mechanical properties of this PAAM/gelatin (PG) hydrogel were optimized to have an elastic modulus of 5.4 kPa by adjusting the PAAM/gelatin ratio. In addition, the PG hydrogel demonstrated a minimal foreign body reaction upon implantation, and the hydrogel displayed a strong resistance to dehydration conditions that can last 40 days in the chamber with 60% humidity. Furthermore, the PG hydrogel demonstrated a self-healing ability that may allow ad-hoc implant augmentation. In addition, tough adhesion of the PG hydrogel resulted in stable attachment to vocal fold tissues. Finally, we demonstrated the functional restoration of voice on an ex vivo canine model by implanting the PG hydrogel as an artificial vocal fold tissue.