Multiple-unit interlocking enhances the single-stranded tiles assembly of DNA nanostructures.

Single-stranded tiles (DNA brick) assembly has provided a simple and modular tool for constructing nanostructures with the potential for numerous applications. However, in this strategy, the short-strand building blocks are susceptible to environmental fluctuations and bring about rapid dissociation during assembly, resulting in instability and prolonged annealing. Thus, developing new strategies which can enhance the stability and accelerate the assembly process of DNA bricks is important. In this study, we applied the kinetically interlocking multiple-unit (KIMU) strategy to tune the process of DNA brick assembly by adopting long DNA strands as building blocks, ranging from tens of to 1000 nucleotides. We constructed a series of DNA structures with improved stability over DNA bricks. Furthermore, the annealing process could be accelerated by increasing the number of units. Our study demonstrated that DNA assembly based on the KIMU strategy using multiple-unit DNA strands could be a promising method for constructing relatively stable DNA nanostructures.