Nanorobots – A New Advancement In DNA Technology
Deoxyribonucleic acid, more commonly known as DNA is a molecule that carries genetic information in human beings as well as other living things.
This information is used to influence the growth, development, functioning and even reproduction of living things. This makes DNA one of the most interesting molecules in nature.
Most people know DNA as having a double helix shape that comprises of 2 single strands of DNA rolled into a coil. Each strand has four other different molecular components called nucleotides. These are;
- Adenine (A)
- Guanine (G)
- Thymine (T)
- Cytosine ©
The arrangement of these four core components in different sequences is what leads to a difference in the genetic information relayed by the molecule.
Armed with this information, researchers have already come up with ways of precisely designing the core molecular components of DNA so as to develop new ways of folding DNA beyond the traditional double helix shape.
The ultimate result is the new possibilities in the use of DNA beyond its traditional use in genetics and other biological purposes. Now, researchers are even using DNA as a building block for nanoscale materials. DNA-based nanomaterials have their use in a wide range of applications, some of which are:
i. Biological Nanobots
In the recent past, researchers have developed different types of biological nanorobots or nanobots as they are simply known. For example, a group of researchers from ETH Zurich and Technion developed a “nano skimmer” that has the capability of moving around biological fluid environments at a speed of 15 micrometers every second. It is possible to use these swimmers to deliver drugs or even target specific cells.
In Harvard Medical School, researchers have designed and developed a nano-scale robot using DNA. The nanobot is then used as a therapeutic delivery vehicle targeting specific cells in the body.
This nanoscale vehicle looks like an open barrel made of DNA. A pivot connects the two halves closed shut by DNA handles. The handles can detect certain combinations of proteins on the surface of the cell, and if they are the right targets, the handles open and the cargo (drug or another therapeutic agent) is released.
Researchers have already demonstrated the nanorobot’s ability to kill cancerous cells while at the same time, leaving healthy cells intact. In one such experiment, the nano-robot targeted and killed half the cancer cells and left the healthy ones untouched.
ii. DNA-based Nanothermometers
One of the most unusual properties of DNA is its tendency to unfold. This process of revealing and losing structure is known as denaturation. Taking advantage of this inherent property of DNA, researchers at the University of Montreal designed strands of DNA that fold and unfold at specific temperatures.
To do this, they used a design rule in which there is a weak bond between nucleotide T and A; and a strong bond between nucleotide C and G. In addition to that, they added light emitting molecules to the DNA structures for monitor and detected changes in temperature.
The researchers programmed molecules to change shape at temperatures between 30 degrees Celsius and 85 degrees Celsius. This allows the use of each molecule as a nano-sized thermal switch.
When there are different molecules in the combination, the result is a very delicate and responsive nanothermometer. These thermometers can detect defects in nanoscale devices by finding any hotspots within the device. It is also possible to use the thermometers to monitor the temperature of individual living cells.
iii. Light-Harvesting Antennas
One of the most common natural processes is photosynthesis. This is a process that allows nature to capture the sun’s light and convert it into chemical energy to be used further as food for plants.
A team of researchers from Arizona State University and the University of British Columbia developed a 3-armed DNA strand that acts as antennas, capturing and absorbing sunlight that gets converted to chemical energy.
Developments such as these facilitate the development of devices that can run on sustainable energy such as sunlight.
iv. Bio-computers in Living Things
DNA structures are capable of shifting between positions and can act as switches. This feature also makes it possible to use DNA structures to perform computer-like functions.
In fact, scientists drawn from Harvard and Bar-Ilan University in Israel have already developed nanoscale robots that use DNA switches to interact with each other.
Furthermore, they have already tested this mechanism in a cockroach, and human trials are on schedule.
In the cockroach trials, the bio-computer switched elements of the cockroach’s DNA structure “on” and “off” to control the delivery of therapeutic agents inside the cockroach.