By imitating nature's design principles, a research team from Harvard University has prepared nanodevices composed of DNA that organizes itself and can be shaped and moved on demand. Unlike existing nanotechnologies, these programmable nanodevices are very suitable for medical applications since DNA Both suitable for the body and can be decomposed in it.
Each such device consists of a circular, single-stranded DNA fragment, which, mixed with many short segments of complementary DNA, arranges itself independently into a desired three-dimensional structure. Double helices of DNA fold into linear and rigid arrays that are connected to each other by single-stranded DNA links. These single-stranded DNA cause the rigid arrays to form three-dimensional structures - similar to the way a tent is built The tension of the ropes connected to its rods. The stability and strength of the structure derive from the way in which the opposing forces of Stretching and compression.
Artists and architects have focused on this architectural principle - called tensegrity - for many years, but it also exists and is common in nature. In the human body, for example, the bones are used as compression bars while the muscles, tendons and ligaments are used as stress absorbers that allow us to stand and thus resist the force of gravity. The same principle governs the cells' ability to change their shape at the micron level.
"This innovative nanoconstruction technology, based on self-assembly, could lead to the development of medical nanodevices and drug delivery systems, such as virus mimics that inject drugs directly into infected cells," said one of the researchers Don Ingber. A nanodevice capable of opening like a spring in response to a chemical or mechanical signal could ensure that the drugs not only reach the defined target but also that they are released at the desired place and time.
Moreover, nanodevices built according to this principle will one day be able to program human stem cells so that they can regrow damaged organs. Stem cells react differently depending on the forces around them. For example, the hard extracellular substrate - the biological "glue" that surrounds the cells - created to mimic the environment of the bones signals the stem cells to form bones, while the "soup"-like substrate found in the brain tissues signals the growth of neurons (nerve cells). "Nanodevices of this type may help us tune and change the stiffness of extracellular substrates in tissue engineering in the future," says Professor Tim Liedl.
"These devices, a sort of tiny "Swiss army knife", will be able to help us develop a variety of measures that could be useful in advanced drug release systems and in the field of tissue and organ regeneration," said lead researcher William Shih. "In addition, we have in our hands a useful biological copy machine of DNA that nature has given us, so these devices can be built easily," said the researcher.
One response
Can these devices be demanded to take care of the brains of some politicians??