Amniotic Mesenchymal Stem Cells Enhance Normal Fetal Wound Healing

Fetal wound healing involves minimal inflammation and limited scarring. Its mechanisms, which remain to be fully elucidated, hold valuable clues for wound healing modulation and the development of regenerative strategies. We sought to determine whether fetal wound healing includes a hitherto unrecognized cellular component. Two sets of fetal lambs underwent consecutive experiments at midgestation. First, fetuses received an intra-amniotic infusion of labeled autologous amniotic mesenchymal stem cells (aMSCs), in parallel to different surgical manipulations. Subsequently, fetuses underwent creation of 2 symmetrical, size-matched skin wounds, both encased by a titanium chamber. One of the chambers was left open and the other covered with a semipermeable membrane that allowed for passage of water and all molecules, but not any cells. Survivors from both experiments had their wounds analyzed at different time points before term. Labeled aMSCs were documented in all concurrent surgical wounds. Covered wounds s...