Artificial Molecular Systems for Complex Functions Based on DNA Nanotechnology and Cell-Sized Lipid Vesicles

Cells are highly functional and complex molecular systems. Artificially creating such systems remains a challenge, which has been extensively studied in various research fields, including synthetic biology and molecular robotics. DNA nanotechnology is a powerful tool for bottom-up engineering for constructing functional nanostructures or chemical reaction networks which can be utilized as components for artificial molecular systems. Encapsulation of these components into a giant unilamellar vesicle (GUV) composed of a lipid bilayer, the base structure of the cellular membrane, results in a functional cell-sized structure that partially mimics some cellular functions. This review discusses the studies contributing to the construction of GUV-based artificial molecular systems based on DNA nanotechnology. Molecular transport and signal transduction through lipid membranes are essential to uptake molecules from the environment and respond to stimuli. Membrane shaping relates to various functions, including motility and signaling. A chemical reaction network is required to autonomously regulate the system‘s functions. This review describes the functions realized using DNA nanostructures and DNA reaction networks. Given the designability and programmability of DNA nanotechnology, it may be possible that the functionality of artificial molecular systems could be comparable to or even surpass that of natural molecular systems.