Special Bioengineering Seminar

The precise identification and purification of target cells is critical to both the study of cell function and the preparation of cells for medical applications. However, intracellular information to distinguish many cell types remains largely inaccessible. We recently developed a method for high-resolution identification, separation, and purification of mammalian cells by quantifying microRNA (miRNA) activities. We designed synthetic mRNAs encoding a protein of interest tagged with target sequences of miRNAs. We found that a set of miRNA-responsive, in vitro synthesized mRNAs identify a specific cell population as a sharp peak and clearly separate different cell types based on less than two-fold differences in miRNA activities. These "miRNA switches" purified variety of target cells, including cardiomyocytes, hepatocytes, and insulin-producing cells,    differentiated from human induced pluripotent stem cells (hiPSCs) with high efficiency, accuracy, and safety. In addition, the designed miRNA switches automatically killed undesired cells without cell sorting. I will also explain synthetic RNA nanostructured devices that control mammalian cell fate.