Overall, we demonstrated that the TANa isothermal conditions allow a simple mix of five DNA strands to self-assemble into nanotubes that grow over days, exceeding the average length achievable with the conventional TAEMg assembly buffer. Given the growing interest in using DNA scaffolds toward the development of composite biomaterials and synthetic cells, we then studied how TANa-assembled nanotubes self-organize when confined in micro-compartments, starting with water-in-oil (W/O) emulsion droplets made of a fluorinated oil and biocompatible-surfactant mixture (Figure ) . The five strands of the single tile design (100 nM in TANa) were encapsulated inside the droplets and the system was incubated at room temperature. With time, the tubes were formed and grew inside the droplets. Notably, after a day, the nanotubes formed started to reorganize inside the droplets to create branched networks (Figure ), in contrast with the bulk conditions where only longitudinal structures were detected. (Figure ). After two days, dense networks were observed inside the droplets, suggesting continued nanotube growth as tiles polymerize. Growth in confinement also induced the formation of bent structures and ring-like morphologies (Figure ). Further, example time-lapse microscopy images and supplementary videos (Figure , Movie S4) show the mobile nature of the nanotubes inside the droplets.