Program Director/Principal Investigator (Last, First, Middle): Vyavahare Narendra R. Project summary The current inability to efficiently derive a sufficient number of mature cardiomyocytes from human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hIPSCs) has severely limited the application of human stem cell technology in treating cardiovascular disease, the leading cause of death worldwide. Significant research has been conducted to engineer soluble factors, such as growth factors and small molecules, to induce cardiac differentiation of hESCs and hIPSCs. In contrast, little work has been done to optimize insoluble factors, such as the substrates on which cells grow, to facilitate cardiac differentiation. Further, the current cardiomyocytes derived from hESCs and hIPSCs are structurally and functionally similar to human embryonic/neonatal stage cardiomyocytes (i.e., immature cardiomyocytes), which have limited clinical applications. Accordingly, we will pursue two specific aims: 1) high throughput assessment of polymeric substrates for enhanced cardiac differentiation of hESCs, and 2) promote terminal differentiation of hESC- derived immature cardiomyocytes by mimicking key aspects of biochemical and biophysical stimuli in developing hearts. We hypothesize in Aim 1 that with high throughput screening of a library of polymeric substrates known to promote hESC clonal growth, substrates capable to enhance cardiac differentiation of hESCs can be identified. We hypothesize in Aim 2 that we can promote maturation of hESC-derived immature cardiomyocytes by mimicking biochemical and biophysical stimuli in developing hearts. This study is innovative: For the first time, we will utilize an emerging polymer microarray technology to develop defined substrates in a high-throughput manner to facilitate cardiac differentiation of hESCs. Further, we will recapitulate key aspects of biochemical and biophysical stimuli of developing hearts to derive mature cardiomyocytes. My long-term career goal is to develop bioengineering approaches for the derivation of a sufficient number of mature cardiomyocytes from hESCs and hIPSCs for cardiac tissue regeneration. The objective of the current proposal is to develop a mechanistic understanding of the effects of environmental factors (e.g., substrates and electrical stimulation) with the intent to use this information in the future for stem- cell based cardiovascular regeneration. The study is significant in that it would allow for efficient derivation of fully mature cardiomyocytes from hESCs, which can have major impacts in drug development and cardiac tissue engineering. The study would tremendously benefit from my mentoring team: Dr. Thomas K. Borg, a well-established developmental biologist, and Dr. Kyu-Ho Lee, MD, a trained pediatric clinician and a faculty member in the Pediatric Cardiology division at MUSC Children's Hospital. The COBRE core facilities will provide a wide range of technical support from stem cell technology to studying hES cell-materials interactions.