In alternative embodiments, provided are macrocellular structures or artificially configured plurality of cells, the so-called “cardioclusters” as provided herein, comprising: a core region or cluster: comprising a plurality of first cardiac stem cells or cardiac progenitor cells and a second region or a peripheral region positioned at least partially surrounding the outer surface of the core region or cluster, or at least partially around the core region or cluster, comprising a plurality of second cardiac stem cells and methods for making and using them. In alternative embodiments, the second cardiac progenitor cells are cardiac progenitor cells or cardiac stem cells, mesenchymal stem cells or mesenchymal progenitor cells, or endothelial progenitor cells or endothelial stem cells.
