|A nanorobot made from DNA has a flap that opens with a mechanical arm (yellow) in response to a target (red).--Courtesy of U. of Udine|
"DNA origami," the act of molding DNA into three-dimensional objects capable of many types of action, is an important innovation in drug delivery, as it allows for precise, robotic methods to transport and release drugs at targeted locations. Now researchers at the Italian University of Udine have developed small nanorobots with a "flap" designed to open and release compounds with unprecedented precision. Their study was published in the journal Small.
Some delivery methods in the past have used small particles with a dissolvable cap to release drugs. But this new system takes that one step further. As opposed to a cap--which after it dissolves is gone forever--the scientists created what is essentially a window that can be pulled open and then shut again when needed, according to a report in Nanowerk.
"As far as our nanorobot is concerned, the lumen is large enough to accommodate a single-stranded nucleic acid, while the nano-object is small enough to be entirely contained within the capsid of viruses," lead author Giuseppe Firrao told Nanowerk. "Our work therefore opens perspectives for the construction of nanorobots that can be hosted within cellular delivery vectors and can host, concurrently, selectively accessible molecular payloads in their internal cavity."
The particle, which is the smallest 3D origami box so far, is a cylinder with a 9-nanometer flap on its long side. The flap is connected to a probe designed to integrate with a specific target, both of which act as an arm to pull the flap open and hold it there, anchored to the side of the particle while drugs are released from the newly opened hole.
The research team is now looking to further monitor the opening of the flap and to get the nanorobot working in vivo, according to the report.
"While in previously developed objects the lids had a lock that can be removed, our container is equipped with a flap moved by an actuator that physically pulls it in the open position," Firrao told Nanowerk. "It is like opening a window on a windy day: you can just unlock it and allow the wind to do the job or you can use your arm to pull the window, keep it firmly open, and eventually close it."