Bio-inspired fiber networks using peptide-DNA nanotechnology

Cytoskeletal proteins such as actin and microtubule build multiscale architectures from filaments and bundles to networks. These architectures are mainly controlled by crosslinking proteins, which orchestrate mesoscale functional structures such as filopodia, lamellipodia, and stress fibers. Such natural self-assembly inspires the engineering of synthetic materials mimicking their structural organization. Numerous studies showed that various synthetic peptides could be self-assembled into well-defined nanostructures including fibers. However, bridging the hierarchical assembly of peptides from nano- to mesoscale remains challenging. Here, we introduce DNA crosslinkers into peptide-based fibrous networks to construct the mesoscale's structural hierarchy. DNA nanotechnologies allow us to systematically vary DNA crosslinkers' physical/chemical properties, such as flexibility, melting temperature, and the number of arms, which cannot be accomplished by conventional chemical crosslinkers. Our multiscale imaging reveals that the structural hierarchy from nanoscale fibers to tactoid-shaped thin bundles to large mesoscale bundles can be successfully introduced and finely controlled by DNA crosslinkers. We found that the structural hierarchy introduced by DNA crosslinkers regulates the mechanics of peptide-DNA networks for more than one order of magnitude. Lastly, we will discuss the application of our peptide-DNA technology to more biologically-relevant systems such as in vitro cytoskeletal filaments.