Restoration of scarred vocal folds using 5 amino acid-deleted type hepatocyte growth factor.

OBJECTIVES/HYPOTHESIS: Our previous studies demonstrated a regenerative effect of recombinant human hepatocyte growth factor (HGF) on vocal fold scarring using full-length HGF. However, clinical application has not yet been achieved because of the lack of a good manufacturing practice (GMP) for full-length HGF. Another natural form of human HGF, 5 amino acid-deleted type HGF (dHGF), has been newly produced under a GMP procedure. In the current study, we investigated the effect of dHGF in comparison with full-length HGF for the treatment of vocal fold scars using a canine model.

STUDY DESIGN

Prospective animal experiment.

METHODS

The vocal folds of nine beagles were unilaterally injured. Four weeks after injury, the vocal folds were treated with an intracordal injection of full-length HGF (full HGF group), dHGF (dHGF group), or phosphate-buffered saline (sham group). Vibratory and histological examinations were performed for each group 6 months after injury.

RESULTS

Vibratory examinations demonstrated significantly lower phonation threshold pressure and a higher ratio of normalized mucosal wave amplitude in both the full HGF and dHGF groups as compared to the sham group. Histological examination showed restoration of hyaluronic acid in both the full HGF and dHGF groups as compared to the sham group. No significant differences were observed for each parameter between the full HGF group and the dHGF group.

CONCLUSIONS

dHGF showed the same potential for regenerative effects on vocal fold scars as full-length HGF. dHGF should be applicable for human clinical trials in patients with vocal fold scars.