Abstract: The present invention generally relates to the field of cell growth and tissue engineering, in particular, tissue engineered compositions comprising a nanotextured substrate which is structurally configured for growth of cells in an anatomically correct adult phenotype in vitro. In particular, described herein are nanotextured substrates which are structurally configured for the anisotropic organization, maturation, and growth of in vitro-differentiated muscle cells, such as cardiomyocytes, and methods for the production and use thereof in varying sizes, nanotextures and substrate rigidities. In vitro-differentiated cardiomyocytes grown on the nanotextured substrates described herein are better-differentiated and more closely mimic adult cardiac tissue than the same cells grown on a non-textured substrate of the same composition.

Abstract: Compositions and methods for improving cardiac function, myocardial contractility and relaxation in a mammal are provided. Cardiomyocytes transfected with one or more expression vectors comprising a ribonucleotide reductase subunit R1-encoding nucleic acid sequence and a ribonucleotide reductase subunit R2-encoding nucleic acid sequence operably linked to a promoter are grafted to a mammalian myocardium. Also provided are compositions and methods for delivering dATP to a myocardium through grafting of donor cells overexpressing R1 and R2. dATP is thereby produced in situ and delivered through gap junctions established between donor cells and host cardiomyocytes. Alternatively, viral vector(s) having the R1 and R2-encoding construct(s) are administered to the mammal directly. Improvement of cardiac function can also be effected by administration of vectors comprising a nucleic acid sequence encoding a L48Q, 61 Q, or L57Q cTnC variant.

Abstract: Compositions and methods for improving cardiac function, myocardial contractility and relaxation in a mammal are provided. Cardiomyocytes transfected with one or more expression vectors comprising a ribonucleotide reductase subunit R1-encoding nucleic acid sequence and a ribonucleotide reductase subunit R2-encoding nucleic acid sequence operably linked to a promoter are grafted to a mammalian myocardium. Also provided are compositions and methods for delivering dATP to a myocardium through grafting of donor cells overexpressing R1 and R2. dATP is thereby produced in situ and delivered through gap junctions established between donor cells and host cardiomyocytes. Alternatively, viral vector(s) having the R1 and R2-encoding construct(s) are administered to the mammal directly. Improvement of cardiac function can also be effected by administration of vectors comprising a nucleic acid sequence encoding a L48Q, 61 Q, or L57Q cTnC variant.

Abstract: In some embodiments, a micro-tissue particle comprising a scaffold-free population of aggregated cells is provided. The micro-tissue particle may have a diameter less than approximately 1 mm. In some aspects the diameter is less than approximately 500? m. The population of cells may include at least one terminally differentiated cell type. In one aspect, the population of cells may include cardiomyocytes, endothelial cells, smooth muscle cells, mesenchymal stem cells, or a combination thereof. The micro-tissue particle may be used to treat or regenerate an injured, degenerated or diseased tissue. For example, micro-tissue particles that include cardiomyocytes may be administered to myocardial tissue that has been injured due to a myocardial infarction.

Abstract: The present invention generally relates to the field of cell growth and tissue engineering, in particular, tissue engineered compositions comprising a nanotextured substrate which is structurally configured for growth of cells in an anatomically correct adult phenotype in vitro. In particular, described herein are nanotextured substrates which are structurally configured for the anisotropic organization, maturation, and growth of in vitro-differentiated muscle cells, such as cardiomyocytes, and methods for the production and use thereof in varying sizes, nanotextures and substrate rigidities. In vitro-differentiated cardiomyocytes grown on the nanotextured substrates described herein are better-differentiated and more closely mimic adult cardiac tissue than the same cells grown on a non-textured substrate of the same composition.

Abstract: The survival of cells during transplantation is enhanced. Cells to be transplanted are administered in a formulation that provides two ore more survival enhancing factors. Optionally, prior to administration, the cells are cultured in the presence of factors that enhance survival, and may be heat shocked prior to transplantation.

Abstract: Viable differentiating cells from in vitro cultures of stem cells are selected for by partial dissociation to provide cell aggregates. Aggregates comprising cells of interest are selected for phenotypic features using methods that substantially maintain the cell to cell contacts in the aggregate.