An in-vivo experimental model for studying wound-healing after laser irradiation in the mouse foetus.

OBJECTIVE: The purpose of this study was to develop an experimental model to study wound-healing in the mouse foetus by inducing an injury with an argon laser. MATERIAL AND METHODS: ICR strain mouse dams were used in this study at day 14 of gestation. Laparotomy was performed on the dams under sodium pentobarbital anaesthesia, and foetuses were exposed from the uterus while wrapped in the amnion. Laser radiation was conducted through the amniotic membrane, and the beam was focused on to the naso-labial region. After laser irradiation, the foetus was returned to the abdominal cavity of the dam. Then the abdominal wall was closed, and an extrauterine pregnancy was maintained. Foetuses were sacrificed at intervals and wound healing was examined histologically. RESULTS: Immediately after laser irradiation, the foetal epithelium was detached and degeneration of the epithelium and subepithelial mesenchymal tissue were observed. Twenty-four hours after laser irradiation, normal epithelial cells surrounding the wound began to migrate along the margin of the degenerate tissue mass. By seventy-two hours after laser irradiation, the laser-induced wound had recovered, and scar formation was not observed. CONCLUSION: The application of an argon laser allowed to inflict a wound on a mouse foetus without damaging the amnion, and this experimental model appeared to be useful for studying the mechanism of foetal wound-healing.