Role of circulating MSCs in vocal fold wound healing

Objectives/Hypothesis: Vocal fold injury can cause intractable scarring resulting in dysphonia. Mesenchymal stem cells (MSCs) have great therapeutic potential in wound healing. They continuously circulate in the peripheral blood and migrate into wound sites where they induce regenerative effects. However, their roles in vocal fold wound healing are poorly understood because few MSCs exist in the peripheral blood and there is no specific marker to identify them. The present study evaluates how intravenously injected MSCs affect vocal fold wound healing using Green Fluorescent Protein (GFP) -labeled MSCs. Study Design: Prospective study using animal model. Methods: GFP-labeled MSCs were obtained from femurs of GFP transgenic Sprague-Dawley rats and incubated in culture. Sprague-Dawley rats underwent intravenous injection of GFP-labeled MSCs (1.0 × 10⁶ cells) immediately after vocal fold injury. Histological examination was performed. Results: Injected MSCs were distributed throughout the vocal fold wound site from day 1 up to day 56. These vocal folds showed increased hepatocyte growth factor (HGF)-positive cells within the wound and improved wound healing compared with sham-treated folds. Conclusion: Circulating MSCs can migrate to vocal fold wound sites and upregulate the expression of HGF during wound healing; thus, they are considered to play a significant role in wound healing within the vocal folds. Laryngoscope, 2012