Drug delivery system of basic fibroblast growth factor using gelatin hydrogel for restoration of acute vocal fold scar

Objective: There continue to be therapeutic challenges in the management of vocal fold scarring. We previously showed that basic fibroblast growth factor (bFGF) injection has therapeutic potential for vocal fold scarring. However, the working time of bFGF is relatively short, and multiple injections were required in many cases to obtain the regenerative effect. An efficacious delivery system for bFGF has yet to be established. We designed a method of sustained drug delivery system (DDS) of bFGF by using a gelatin hydrogel. Hydrogel has been developed for targeted delivery and controlled release of bFGF. Hydrogel of the particle type is also injectable and commercially available. The current study aims to investigate the effects of a single injection of bFGF-DDS on acute vocal fold scarring using a canine model. Methods: Vocal folds from eight beagles were unilaterally scarred by stripping the lamina propria. One month later, hydrogels (0.5 ml) containing 10 mu g of bFGF were injected into the scarred vocal folds of four beagles (FGF-hydrogel group). Saline (0.5 ml) was injected into the other four beagles (sham group). Vibratory and histological examination of excised larynges was performed 5 months after treatment. Comparative analysis between the current data and our previous data with repeated injection of bFGF solution was also completed. Results: Vibratory examination demonstrated significantly improved vibration in the bFGF hydrogel-treated group. Histological examination of the bFGF hydrogel group showed restoration of hyaluronic acid in the lamina propria as compared to sham. Comparison between the DDS system and our previous bFGF solution injection indicated better effects of the DDS system on vibratory amplitude. Conclusion: A single injection of bFGF hydrogel has regenerative effects on acute vocal fold scarring, which is at least similar to repeated injection of bFGF solution. (C) 2016 Elsevier Ireland Ltd. All rights reserved.