Nanomedicine is an emerging field which seeks to uses nanoparticles for more precise diagnosis and treatment for a wide variety of diseases. Researchers at Bar-Ilan University have developed a nanobot computer out of DNA strands that were structured to act as a computer circuit. These DNA strands were then injected into live cockroaches in order to perform certain tasks. The research was led by Ido Bachelet and was published in Nature Nanotechnology.
The DNA was manipulated so it would self-assemble into a box with a controllable lid, using principles of origami. In the case of this study, each DNA box contained a molecule that binds hemolymph cells, which is the arthropod version of blood. The DNA nanobots were tagged with fluorescent markers in order to track their position within the roaches’ bodies and observe their progress.
Of course, there are thousands upon thousands of different types of proteins in a cockroach, so regulating which ones the DNA will interact with has to be carefully controlled. Additionally, proteins aren’t synthesized and delivered neatly like in a textbook diagram; there’s a fair bit of randomness and everything is just sort of bumping around together.
The circuitry is designed to perform different logic gates: AND, NAND, OR, XOR, NOT, CNOT, and half adder, depending on which proteins are present. When the targeted proteins interact with the DNA box, the lid springs open and the chemical payload is delivered. The specificity is increased by programming the gate so multiple protein signatures of DNA boxes as well as particular cockroach proteins are needed to administer the hemolymph binder.
DNA has been manipulated into biological circuits for 20 years, but this is the first time it has been applied to a living organism. The researchers are hoping to continue along this path and create nanobots with the power of an 8-bit computer, like a Commodore 64. Because of DNA’s natural ability to interact with proteins, it has been a very desirable vehicle for target drug delivery. Targeted drug delivery has the potential to revolutionize how cancer is treated.
Traditional chemotherapeutic agents that are strong enough to kill the cancer cells wreak havoc on the body’s healthy cells and cause a host of harsh side effects. If a nanobot could deliver the chemo drugs specifically to the cancer cells while drastically decreasing the amount healthy cells exposed to the medication, everything would change. The researchers were so encouraged by the results of the study, they claim that human trials could be as few as five years away.