3 research outputs found
Simple Design for DNA Nanotubes from a Minimal Set of Unmodified Strands: Rapid, Room-Temperature Assembly and Readily Tunable Structure
DNA nanotubes have great potential as nanoscale scaffolds for the organization of materials and the templation of nanowires and as drug delivery vehicles. Current methods for making DNA nanotubes either rely on a tile-based step-growth polymerization mechanism or use a large number of component strands and long annealing times. Step-growth polymerization gives little control over length, is sensitive to stoichiometry, and is slow to generate long products. Here, we present a design strategy for DNA nanotubes that uses an alternative, more controlled growth mechanism, while using just five unmodified component strands and a long enzymatically produced backbone. These tubes form rapidly at room temperature and have numerous, orthogonal sites available for the programmable incorporation of arrays of cargo along their length. As a proof-of-concept, cyanine dyes were organized into two distinct patterns by inclusion into these DNA nanotubes
Stoichiometry and Dispersity of DNA Nanostructures Using Photobleaching Pair-Correlation Analysis
A wide
variety of approaches have become available for the fabrication
of nanomaterials with increasing degrees of complexity, precision,
and speed while minimizing cost. Their quantitative characterization,
however, remains a challenge. Analytical methods to better inspect
and validate the structure and composition of large nanoscale objects
are required to optimize their applications in diverse technologies.
Here, we describe single-molecule fluorescence-based strategies relying
on photobleaching and multiple-color co-localization features toward
the characterization of supramolecular structures. By optimizing imaging
conditions, including surface passivation, excitation power, frame
capture rate, fluorophore choice, buffer media, and antifading agents,
we have built a robust method by which to dissect the structure of
synthetic nanoscale systems. We showcase the use of our methods by
retrieving key structural parameters of four DNA nanotube systems
differing in their preparation strategy. Our method rapidly and accurately
assesses the outcome of synthetic work building nano- and mesoscale
architectures, providing a key tool for product studies in nanomaterial
synthesis
Three-Dimensional Organization of Block Copolymers on āDNA-Minimalā Scaffolds
Here, we introduce a 3D-DNA construction method that
assembles
a minimum number of DNA strands in quantitative yield, to give a scaffold
with a large number of single-stranded arms. This DNA frame is used
as a core structure to organize other functional materials in 3D as
the shell. We use the ring-opening metathesis polymerization (ROMP)
to generate block copolymers that are covalently attached to DNA strands.
Site-specific hybridization of these DNA-polymer chains on the single-stranded
arms of the 3D-DNA scaffold gives efficient access to DNA-block copolymer
cages. These biohybrid cages possess polymer chains that are programmably
positioned in three dimensions on a DNA core and display increased
nuclease resistance as compared to unfunctionalized DNA cages