Uniform DNA gel formation in monodisperse GUV

We attempted to control the generation and resultant size of DNA condensates (DNA gel and DNA droplet) comprised of sequence-designed ssDNA encapsulated in monodisperse giant unilamellar vesicles (GUVs) fabricated using microfluidic channels. By applying the osmotic shrinkage of GUVs, the internal contents including DNA nanostructures and salts were gradually concentrated to form DNA condensates. We investigated the effects of important parameters such as the length of sticky ends, DNA concentration, and salinity on the formation of DNA condensates. We found conditions under which the DNA condensates developed and grew as the GUV shrunk at room temperature. The present approach enabled the formation of uniform DNA condensates within a cell-sized lipid vesicle as a mimic of a nucleus, providing a method to construct the hierarchical structure of artificial cells.