Phenotypic characterization of the hUCMSC sheet and transplantation in an AMI mouse model. (A) hUCMSCs isolated from the donor umbilical cord at P4 cell morphology stage. Scale bar = 200 μm. (B) hUCMSCs cultured in a temperature-responsive culture dish overnight; sheet formation can be seen. (C) Immunostaining of hUCMSC sheet demonstrated the expression profile of fibronectin (green). Cells were also counterstained with DAPI for nuclei (blue). Scale bar = 100 μm. (D) Immunostaining of hUCMSC sheet demonstrated the expression profile of β1-integrin (green). Cells were also counterstained with DAPI for nuclei (blue). Scale bar = 100 μm. (E) AMI mouse model established and hUCMSC sheet transplanted to cover the ischemic location. (F) Electrocardiogram monitoring indicating the MI group showed ST segment elevation. hUCMSC, human umbilicalcord mesenchymal stem cell; AMI, acute myocardial infarction; DAPI, 4′,6-diamidino-2-phenylindole; MI, myocardial infarction. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)