2017 年 29 巻 1 号 p. 1-7
Myelomeningocele (MMC) is the most common form of congenital neural tube defect. Current fetal surgical repair performed to prevent the exposed spinal cord from being injured until delivery cannot reverse those injuries already inflicted in utero. “Cell sheet” technology has been adopted successfully for the regeneration of diverse organs and tissues, although this promising modality has not yet been used for fetal therapy. This study thus tested our hypothesis that fetal MMC tissue histologically injured in utero could be regenerated using cell sheet technology. We used the L6 myoblast cell line derived from rat skeletal muscle for the cell sheet engineering. A fetal MMC model was also obtained from pregnant Sprague-Dawley (SD) rats fed orally with retinoic acid (60mg/kg, embryonic day 10). Cell sheets were then transplanted onto the fetal MMC lesion (embryonic day 19) following maternal anesthesia, laparotomy, and hysterotomy. The incisional wound of the uterus was kept open for 4 hours under anesthesia with the MMC lesion maintained outside the body with the transplanted cell sheet. Subsequently, the experimental fetuses were sacrificed for histological (HE stain) and immunohistochemical studies to evaluate viability and differentiation potential based on cell markers of the transplanted L6 myoblasts. Immunohistochemical studies clearly demonstrated cell-sheet markers specific to neurons, skeletal muscle, and myoblasts within the treated MMC lesions, confirming that the cell sheet was biologically implanted within 4 hours after the procedure. Cell sheet technology could be useful for intrauterine regeneration of the fetal rat spinal cord injured by an associated MMC.
