Researchers at the University of Sydney Nano Institute have made a significant advance in the field of molecular robotics by developing custom-designed and programmable nanostructures using DNA origami.
This innovative approach has potential across a range of applications, from targeted drug delivery systems to responsive materials and energy-efficient optical signal processing. The method uses 'DNA origami', so-called as it uses the natural folding power of DNA, the building blocks of human life, to create new and useful biological structures.
As a proof-of-concept, the researchers made more than 50 nanoscale objects, including a 'nano-dinosaur', a 'dancing robot' and a mini-Australia that is 150 nanometres wide, a thousand times narrower than a human hair.
The research is published today in the pre-eminent robotics journal Science Robotics .
The research, led by first author Dr Minh Tri Luu and research team leader Dr Shelley Wickham , focuses on the creation of modular DNA origami "voxels" that can be assembled into complex three-dimensional structures. (Where a pixel is two-dimensional, a voxel is realised in 3D.)
These programmable nanostructures can be tailored for specific functions, allowing for rapid prototyping of diverse configurations. This flexibility is crucial for developing nanoscale robotic systems that can perform tasks in synthetic biology, nanomedicine and materials science.
Dr Wickham, who holds a joint position with the Schools of Chemistry and Physics in the Faculty of Science, said: "The results are a bit like using Meccano, the children's engineering toy, or building a chain-like cat's cradle. But instead of macroscale metal or string, we use nanoscale biology to build robots with huge potential."
Dr Luu said: "We've created a new class of nanomaterials with adjustable properties, enabling diverse applications – from adaptive materials that change optical properties in response to the environment to autonomous nanorobots designed to seek out and destroy cancer cells."
VELCRO DNA
To assemble the voxels, the team incorporate additional DNA strands on to the exterior of the nanostructures, with the new strands acting as programmable binding sites.
Dr Luu said: "These sites act like Velcro with different colours – designed so that only strands with matching 'colours' (in fact, complementary DNA sequences) can connect."
He said this innovative approach allows precise control over how voxels bind to each other, enabling the creation of customisable, highly specific architectures.
One of the most exciting applications of this technology is its potential to create nanoscale robotic boxes capable of delivering drugs directly to targeted areas within the body. By using DNA origami, researchers can design these nanobots to respond to specific biological signals, ensuring medications are released only when and where they are needed. This targeted approach could enhance the effectiveness of cancer treatments while minimising side effects.
In addition to drug delivery, the researchers are exploring the development of new materials that can change properties in response to environmental stimuli. For instance, these materials could be engineered to be responsive to higher loads or alter their structural characteristics based on changes in temperature or acidic (pH) levels. Such responsive materials have the potential to transform medical, computing and electronics industries.
Dr Wickham said: "This work enables us to imagine a world where nanobots can get to work on a huge range of tasks, from treating the human body to building futuristic electronic devices."
The research team is also investigating energy-efficient methods for processing optical signals, which could lead to improved image verification technologies. By harnessing the unique properties of DNA origami, these systems could improve the speed and accuracy of optical signal processing, paving the way for enhanced techniques in medical diagnostics or security.
Dr Luu, a postdoctoral researcher in the School of Chemistry, said: "Our work demonstrates the incredible potential of DNA origami to create versatile and programmable nanostructures. The ability to design and assemble these components opens new avenues for innovation in nanotechnology."
Dr Wickham said: "This research not only highlights the capabilities of DNA nanostructures but also emphasises the importance of interdisciplinary collaboration in advancing science. We are excited to see how our findings can be applied to real-world challenges in health, materials science and energy."
As researchers continue to refine these technologies, the potential for creating adaptive nanomachines that can operate in complex environments, such as within the human body, is becoming increasingly feasible.
