Preliminary Research Of The Regeneration Of Injured Rabbit Vocal Folds After The Transplantation Of Human Amniotic Epithelial Cells

Objective To investigate the survival, growth and distribution of human amniotic epithelial cells (hAECs) after injected into injured rabbit vocal folds and assess the ability of hAECs to prevent vocal fold scarring. Methods hAECs were isolated from human amnion and the isolated cells were transfected with enhanced green fluorescent protein (EGFP) gene using lentiviral vectors. Fifteen New Zealand rabbits were used for this experiment, hAEC-EGFP were injected into the left injured vocal folds in thirteen rabbits, and the contralateral thirteen folds of the same animal experienced an injured procedure only ("injured untreated control"), and four vocal folds were left as untreated controls. The survival, distribution and differentiation potential of hAECs were examined by immunofluorescence method. HE staining and immunohistochemical staining were performed for the evaluation of collagen and fibronectin respectively. Results hAECs showed a cobblestone-like growth. After implanted into the injured vocal folds, hAECs could survive in vocal fold lamina propria for2months. The immunofluorescence analysis showed the evidence of hAECs differentiation into muscle cells. Three months postoperatively, the density of collagen was higher in the injured untreated control folds than that in the injured vocal folds injected with hAECs and the untreated controls. Besides, the content of fibronectin in the injured untreated control group was significantly increased. Conclusions hAECs survived in the vocal folds lamina propria, and had the potentiality to differentiate into vocal folds tissue. The histological improvement caused by the injected cells demonstrate that hAECs had the ability to promote the repairment and regeneration of injured vocal folds.