Chronic vocal fold scar restoration with hepatocyte growth factor hydrogel.
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.
Kishimoto
Yo
Y
Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
Hirano
Shigeru
S
Kitani
Yoshiharu
Y
Suehiro
Atsushi
A
Umeda
Hiroo
H
Tateya
Ichiro
I
Kanemaru
Shin-ichi
S
Tabata
Yasuhiko
Y
Ito
Juichi
J
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*
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D017228:Hepatocyte Growth Factor