title: Chronic vocal fold scar restoration with hepatocyte growth factor hydrogel.
abstract: OBJECTIVE
  Therapeutic challenges exist in the management of vocal fold scarring. We have previously demonstrated the therapeutic potential of hepatocyte growth factor (HGF) in the management of acute phase vocal fold scarring using a novel hydrogel-based HGF drug delivery system (DDS). However, the effect of HGF on matured vocal fold scarring remains unclear. The current study aims to investigate the effect of HGF-DDS on chronic vocal fold scarring using a canine model.
  
  
  METHODS
  Animal model.
  
  
  METHODS
  Vocal folds from eight beagles were unilaterally scarred by stripping the entire layer of the lamina propria; contralateral vocal folds were kept intact as normal controls. Six months after the procedures, hydrogels (0.5 mL) containing 1 microg of HGF were injected into the scarred vocal folds of four dogs (HGF-treated group). Hydrogels containing saline solution were injected into the other four dogs (sham group). Histological and vibratory examinations on excised larynges were completed for each group 9 months after the initial surgery.
  
  
  RESULTS
  Experiments conducted on excised larynges demonstrated significantly better vibrations in the HGF-treated group in terms of mucosal wave amplitude. Although phonation threshold pressure was significantly lower in the HGF-treated group compared with the sham group, no significant differences were observed in the normalized glottal gap between HGF-treated and sham groups. Histological examinations of the HGF-treated vocal folds showed reduced collagen deposition and less tissue contraction with favorable restoration of hyaluronic acid.
  
  
  CONCLUSIONS
  Results suggest that administration of HGF may have therapeutic potential in the treatment of chronic vocal fold scarring.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Yo
authors.initials: Y
authors.lastname: Kishimoto
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hirano
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kitani
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suehiro
authors.forename: Hiroo
authors.initials: H
authors.lastname: Umeda
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tateya
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kanemaru
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tabata
authors.forename: Juichi
authors.initials: J
authors.lastname: Ito
mesh_terms: D000818:Animals; D002908:Chronic Disease; D002921:Cicatrix / Q000473:pathology; D004285:Dogs; D016503:Drug Delivery Systems; D017228:Hepatocyte Growth Factor / Q000008:administration & dosage*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D014732:Vibration; D014827:Vocal Cords / Q000187:drug effects / Q000473:pathology*
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D017228:Hepatocyte Growth Factor