Imagine designing parts that can self-assemble into a house. Now imagine that these same houses can self assemble into cities. On the nanoscale, as for biomolecules and tissues, this scenario is so commonplace that it hardly deserves mention: Your entire body, and every other living thing on Earth, self-assembled. If the designer is not the whole of nature itself, however, but a human with a fancy CAD program calling the shots, you might sit up and take notice. A company called Parabon Nanolabs has recently developed a suite of CAD tools and technologies to do just that.

A press release from the National Science Foundation describes a new project at Parabon, which it has chosen to fund. While there are many applications in microelectronics, optics, and sensor technology where the ability to precisely engineer nanostructures would be invaluable, the ability to nanotailor drugs for treating cancer is ripe and low-hanging fruit. For Parabon, developing a new product for a customer proven to have deep pockets is a great place to start. In this particular case the kind of cancer that has been targeted is known as glioblastoma, the disease that Ted Kennedy famously fought a couple of years ago.

Cancer medicines are typically so expensive that a real price per molecule can be discussed using familiar numbers. For this reason insurance companies do not want to be caught paying for any extra molecules if the prescription only requires a certain amount. They also want to be sure that the drug company is providing the amount claimed. Platinum for example, is more expensive than gold even before it is turned into a medicine. To use it as a cancer treatment, any sample must be pure and the quantity known, and regulated as such. Beyond that it must be turned into a molecule that the body can properly absorb, distribute to the right tissue, metabolize, and excrete in a way that ensures sufficient time to function. Each of these steps can add an order of magnitude to cost — and that’s just for simple metal ion.

Parabon’s InSequio design studio enables drug designers to build up molecules step-by-step from drag-and-drop menus, and quantify them in the process. In addition to being able to rotate and bend components in a CAD-like environment, InSequio also calculates the forces the molecules feel from their neighbors and the effects they have on the structure and strength of bonds. The building blocks InSequio uses are nuclei acids, in particular the four familiar base molecules of which DNA is made. The design is optimized using a supercomputing cloud platform they call the Parabon Computational Grid which searches for sets of DNA sequences that can link properly to self-assemble.

The DNA itself is not the drug. The DNA is the ferry that brings to bear the drug or other molecule of interest that is bound to it. The DNA also acts as the selector that tags the correct drug, the counter that determines its total number, and the matrix that stabilizes it in a permanent structure. Many cancers are currently treated with a medicinal cocktail, which for some reason is invariably prescribed as a combination of four drugs and designated with a four-letter word. The right blend for one patient is not the necessarily the proper one for the next, and neither is the dose. Excess drug and mismatch of inventory to demand is a problem no cancer treatment center wants to have, particularly when shelf life is limited. Hospital and pharmacy error is also a significant problem. On-demand DNA-based assembly suddenly makes many of these problems recede into the distance.

The particular language used by Parabon’s founder, Steven Armentrout, at first sounds almost fanciful. If asked to explain the same you might chose similar words. Armentrout describes complementary sequences of DNA as being programmed to “swim to the right spot” to form structures of virtually any shape. Furthermore he details how we can now “print” molecule by molecule exactly the compound we want. To a large extent these statements are indeed true, but it is important to be mindful of the scope and metaphor.

The ability to program-in new functional molecules is nearly as limitless as one might have bar codes to track the vials in which store them. For drugs, your custom pill could also have all the other things that might be needed rolled into one. Drugs to treat the side-effects of the primary treatment, anti-nausea medicine, blood thinners, pain controllers, and whatever else.

For now, the methods that Parabon uses to create its starter molecules — the relatively short DNA strands to which a drug or other molecule is actually bound to — are synthesized by the trillions in identical form with standard methods, probably traditional PCR. This is not, in a strict sense, identified with the 3D printing methods of today. As the technology evolves, the “building of the house” may become more closely knit within the same platform to the “building of the city,” and PCR machines may evolve to become more like 3D printers. The extent to which this is already happening is tough to know, but we can be sure of one thing, it is definitely happening.

Now read: 3D printing: a replicator and teleporter in every home