DNA is often referred to as a “building block” for life, but perhaps a better metaphor would be LEGO. Research in manipulating DNA molecules has led to a robust set of abilities in snapping it together to create complex 2D and 3D shapes. DNA’s code-based organization made it possible to design linear molecules that would fold and snap together in predictable ways — under laboratory conditions.

Now, a new method of designing DNA structures has not only automated much of the shape-creation process, allowing scientists to shape their molecule directly, but builds that molecule to be more stable than any previous attempt at DNA “origami.”

The thing about DNA is that much of the chemical bonding that holds it into complex structures is transient. The adhesion offered by hydrogen bonding, for instance, is dependent on a wide range of things. Not the least of these is salt concentration, and prior attempts to use DNA to make nano-scale sculpture have required high levels of magnesium salt to keep the final shape from unraveling.

The new technique, recently revealed by researchers from Sweden’s Karolinska Institutet, gets around this by building its models out of relatively stable double helices. Every edge in the computer wire-frame ends up represented by a self-contained double helix in the final molecules, where previous technologies have mostly used closely packed bundles of single-stranded helices. Doing it this way takes more premeditation in code design and shape assembly, and thus the newly advanced shaping algorithms, but once made they have a much better ability to actually go to work in the body.

Up until now, most attempts at improving the stability of engineered DNA nano-structures have looked to use whole different versions of DNA, a class of synthetic nucleic acids collectively called XNA. The idea was that since DNA cages and bunny rabbits don’t have to act as genetic material for a cell, they have a much narrower list of chemical requirements than natural DNA. This approach allows useful object creation without the need to reinvent the proverbial wheel.

The automation on display here has been called a 3D printing solution for DNA, and in terms of ease of use that label certainly fits. All they need to do is have their algorithms design a set of DNA molecules coded so that they could only realistically assemble in a certain way, in certain conditions. Then, a third party created those linear DNA strands for them — all the team had to do was put this collection of strands through the warming and cooling of the assembly process, and they did the rest of the world themselves.

As to why scientists would particularly want to be able to create everything from DNA spheres to DNA Coke bottles, it really comes down to which area of science they study. DNA microcapsules have been studied for their potential to deliver drugs directly to where they’re needed most. And since DNA can be programmed, it could be used as a sort of injectable physical tool, perhaps grabbing pores in the blood-brain barrier and holding them open for a new therapeutic molecule. They could be programmed to grab on to only one sort of marker (say, a surface protein on a cancer cell) and change conformation to attract further attention.

DNA isn’t perfect, and certainly on a long enough timescale it seems likely that techniques like this will be combined with exotic XNA molecules. Still, this breakthrough manages to get somewhat exotic durability out of plain old DNA. That should make the dreams of many researchers far more achievable.