Abstract
Self-assembly of nanoscale synthetic subunits is a promising bottom-up
strategy for fabrication of functional materials. Here, we introduce a design
principle for DNA origami nanoparticles of 50-nm size, exploiting modularity,
to make a family of versatile subunits that can target an abundant variety of
self-assembled structures. The subunits are based on a core module that remains
constant among all the subunits. Variable bond modules and angle modules are
added to the exterior of the core to control interaction specificity, strength
and structural geometry. A series of subunits with designed bond/angle modules
are demonstrated to self-assemble into a rich variety of structures with
different Gaussian curvatures, exemplified by sheets, spherical shells, and
tubes. The design features flexible joints implemented using single-stranded
angle modules between adjacent subunits whose mechanical properties, such as
bending elastic moduli, are inferred from cryo-EM. Our findings suggest that
incorporating a judicious amount of flexibility in the bond provides error
tolerances in design and fabrication while still guaranteeing target fidelity.
Lastly, while increasing flexibility could introduce greater variability and
potential errors in assembly, these effects can be counterbalanced by
increasing the number of distinct bonds, thereby allowing for precise targeting
of specific structural binding angles within a broad range of configurations.