DNA origami nanorobot (ASU / NCNST)

Overview

A cancer-fighting robot built entirely from DNA. It uses DNA origami, a method that folds one long DNA strand into a set shape with short "staple" strands. A flat 90 × 60 nm sheet carries an average of four molecules of thrombin, a blood-clotting enzyme. The sheet rolls into a tube about 19 nm wide, hiding the thrombin inside. The tube is held shut by aptamers, short DNA strands that grip one target molecule. Here the target is nucleolin, found on tumor blood vessel walls. When the aptamer locks meet nucleolin, the tube opens and exposes the thrombin. Clots then block the tumor's blood supply. Its "program" is this fixed lock logic, so it has no programmability in the computer sense. Earlier, Shawn Douglas, Ido Bachelet and George Church at Harvard's Wyss Institute built a DNA origami barrel with aptamer locks that acted as a logic gate (Science, 2012).

The ASU and NCNST team reported results in Nature Biotechnology in February 2018. Within 24 hours of injection, tumor blood vessels in mice were blocked. Advanced clotting followed by 48 hours, and dense clots filled all tumor vessels by 72 hours. In a melanoma model, 3 of 8 treated mice had complete tumor regression, and median survival rose from 20.5 to 45 days. Breast, ovarian and lung tumor models also responded, and the robot prevented metastasis. It showed no clotting changes or spread to the brain in normal mice and Bama miniature pigs. The team said in 2018 it was seeking clinical partners. As of 2026, no human trial of this nanorobot has been reported (unconfirmed). The same NCNST group later built a DNA tube vaccine with acid-triggered locks (Nature Materials, 2021). All results so far are in animals.