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. The nanotextured substrate/cell constructs provide a platform for screening to predict the effect of test agents or drugs on, for example, human cardiac tissue, including patient-derived tissue, or for the identification of agents that effect various cardiac functional parameters.