Fig. 3From: Allogeneic umbilical cord-derived mesenchymal stem cell transplantation for treating chronic obstructive pulmonary disease: a pilot clinical studyUC-MSC culture and expansion. The MSCs migrated from the tissue after 7 days of primary culture (a). They were subcultured for UC-MSC mater banks (b). The UC-MSCs were thawed and cultured for transplantation (c)Back to article page