Fig. 1: Overview of procedure to construct DNA cyto- or exoskeletal protocells and prototissues.
From: Creating complex protocells and prototissues using simple DNA building blocks
A Five component oligonucleotides anneal to form DNA nanotubes (NT), or fibers (F) (green) at different MgCl2 concentrations, DNA nanotubes form at 14 mM MgCl2, while fibers with increasing diameter and stiffnesses form at higher Mg concentrations, left to right, and cholesterol-labeled (orange ellipsoids) 100 mM MgCl2 DNA fibers, far right. B Protocells generated using an inverted emulsion procedure enable DNA macrostructures to be compartmentalized inside GUVs. DNA structures (green) in aqueous buffer are added to a lipid-oil layer (yellow box) which forms an emulsion droplet (gray sphere) surrounded by a lipid monolayer. Upon centrifugation, the dense droplets migrate to the aqueous phase (blue box), which is covered in a lipid monolayer (gray line) to form lipid bilayer protocells containing internalized DNA cytoskeletons. C Exoskeleton protocells are generated by adding external nanotubes or fibers (magenta) using an optional two-step procedure. First cholesterol labeled DNA single strands are added which bind to GUVs, then “hairy” DNA nanotubes or fibers are added which hybridize to coat protocells. D Assembling prototissues from protocells using evaporation induced convection (EIC), attractive forces and cross-linking DNA fibers (left to right). GUVs are deposited in a glucose-aqueous droplet (blue) on a glass surface (gray line), upon EIC and weak electrostatics, organize into prototissues, which can be cross-linked by adding additional “hairy” DNA nanotubes or fibers to modify prototissue morphology and connectivity. DNA nanotubes vary in diameter from 7–22 nm; for clarity the DNA nanotubes are represented as 14 helix bundles.
