DNA origami-templated nanopatterning of small unilamellar liposomes

• Applicant: Dr. Marko Skugor
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Biological and Biomimetic Chemistry
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 522144268

Hierarchical self-assembly utilizes predefined molecular and supramolecular interactions to arrange nanoscale components into larger complexes of arbitrary shape. One of the many attractive possibilities afforded by this approach is construction of hybrid nanoarchitectures that function as artificial biomaterials. DNA and lipids are two biomolecule types with great potential for fabrication of artificial hybrid materials, despite and because of their very different biophysical properties. DNA is a carrier of genetic information that has in recent decades been utilized as a construction material for DNA origami, a technique of folding DNA into solid, programmable, and positionally addressable nanoscale shapes. Lipids, on the other hand, self-assemble into lipid bilayers and lipid vesicles in aqueous environments. Lipid vesicles are soft fluid spheres commonly used as compartmentalizing agents for drug delivery or as an interface to study biophysical processes on lipid membranes. By making use of DNA-modified cholesterol that embeds itself in lipid membranes, DNA origami and lipid vesicles can readily interact and connect with full control over their spatial relationship and relative stoichiometry. This proposal aims to make use of this feature by designing and assembling lattices out of DNA origami that would enable arranging small unilamellar lipid vesicles (SUVs, ≤ 100 nm) in two-dimensionally periodic geometric patterns. The lattice framework is constructed using a DNA origami socket designed to hold SUVs ranging in size between 25 and 70 nm and to polymerize into a square lattice. The DNA origami framework thereby acts as a rigid platform that defines the arrangement pattern and exposes attachment slots for SUVs to dock into. The versatility of this approach is demonstrated by the possibility of constructing lattices displaying a variety of different geometric patterns, including those able to incorporate multiple different SUV types. SUV arrangements will be characterized by TEM and DNA-PAINT techniques. Both techniques are suitable also for characterization of heterogenous arrangements. Gold nanoparticles can be incorporated in one of the SUV species deposited on the lattice as a contrasting agent in TEM. DNA-PAINT can be adapted for heterogenous characterization through the use of different orthogonal fluorophores incorporated in two different SUV species. This approach can benefit efforts to organize chemical reactions and reaction cascades, construction of biosynthetic platforms that serve as infrastructure in the exchange of cargo, organize photoemitting elements, and nanofabrication in general.

• DFG Programme: WBP Position