A tiny robot was constructed entirely from DNA by scientists from Inserm, CNRS, and Université de Montpellier at the Structural Biology Center in Montpellier. The nano-robot could lead to a closer study of the mechanical forces applied at microscopic levels, which are important for various biological and pathological processes.
The study was published in Nature Communications.
Our cells face mechanical forces that are exerted on a microscopic scale, and these forces trigger biological signals that are essential to many cell processes responsible for the normal functioning of our body or the development of certain diseases.
Dysfunction of cellular mechanosensitivity is involved in various diseases where the impacted cells migrate within the body by surrounding and adapting to the mechanical properties of their microenvironment. This adaptation is only possible because specific forces are detected by mechanoreceptors, which transmit the information to the cell cytoskeleton.
Our current knowledge of the molecular mechanisms involved in cell mechanosensitivity is very limited, so the research team led by Inserm researcher Gaëtan Bellot at the Structural Biology Center (Inserm/CNRS/Université de Montpellier) decided to use an alternative method referred to as the DNA origami method.
DNA Origami Method
The DNA origami method enables the self-assembly of 3D nanostructures in a predefined form using the DNA molecule as construction material. The technique has been responsible for major advances in the nanotechnology field.
The team used the method to design a “nano-robot” that consists of three DNA origami structures. It is compatible with the size of a human cell, and for the first time, it makes it possible to apply and control a force with a resolution of 1 piconewton, which is one trillionth of a Newton. One Newton can be compared to the force of a finger clicking on a pen.
The new development is the first time that a human-made and self-assembled DNA-based object can apply force with this level of accuracy.
The team coupled the robot with a molecule that recognizes a mechanoreceptor, which made it possible to direct the robot to some of our cells. They could also specifically apply forces to targeted mechanoreceptors localized on the surface of the cells to activate them.
The tool could prove highly valuable for basic research. It can help experts better understand the molecular mechanisms involved in cell mechanosensitivity, as well as lead to the discovery of new cell receptors sensitive to mechanical forces.
“The design of a robot enabling the in vitro and in vivo application of piconewton forces meets a growing demand in the scientific community and represents a major technological advance. However, the biocompatibility of the robot can be considered both an advantage for in vivo applications but may also represent a weakness with sensitivity to enzymes that can degrade DNA. So our next step will be to study how we can modify the surface of the robot so that it is less sensitive to the action of enzymes. We will also try to find other modes of activation of our robot using, for example, a magnetic field,” says Bellot.