Tag Archives: nanorobots

These nanobots powered by magnets can successfully remove water pollutants

Surface water, including lakes, canals, rivers, and streams, is a key resource for agriculture, industries, and domestic households. It’s quite literally essential to human activity. However, it’s also very susceptible to pollution, and cleaning it up is rarely easy. But we may have a new ally in this fight: nanobots.

Image credit: Wikipedia Commons.

According to the UN, 90% of sewage in developing countries is dumped untreated into water bodies. Industries are also to blame, as they dispose of between 300 and 400 megatons of polluted water in water bodies every year. Nitrate, used extensively by agriculture, is the most common pollutant currently found in groundwater aquifers.

Once these pollutants enter into surface water, it’s very difficult and costly to remove them through conventional methods, and hence, they tend to remain in the water for a long time. Heavy metals have been detected in fish from rivers, which hold risks to human health. Water pollution can also progress to massive disease outbreaks.

The use of nanotechnology in water treatment has recently gained wide attention and is being actively investigated. In water treatment, nanotechnology has three main applications: remediating and purifying polluted water, detecting pollution, and preventing it. This has led to a big demand lately for nanorobots with high sensitivity

However, there’s a technical challenge. Most nanorobots use catalytic motors, which cause problems during their use. These catalytic motors are easily oxidized, which can restrict the lifespan and efficiency of nanorobots. This is where the new study comes in.

A new type of nanorobot

Martin Pumera, a researcher at the University of Chemistry and Technology in the Czech Republic, and his group of colleagues developed a new type of nanorobots, using a temperature-sensitive polymer material and iron oxide. The polymer acts like small hands that pick up and dispose of the pollutants, while the oxide makes the nanorobots magnetic.

The robots created by Pumera and his team are 200 nanometers wide (300 times thinner than human hair) and are powered by magnetic fields, allowing the researchers to control their movement. Unlike other nanorobots out there, they don’t need any fuel to function and can be used more than one time. This makes them sustainable and cost-effective.

In the study, the researchers showed that the uptake and release of pollutants in the surface water are regulated by temperature. At a low temperature of 5ºC, the robots scattered in the water. But when the temperature was raised to 25ºC they aggregated and trapped any pollutants between them. They can then be removed with the use of a magnet.

The nanorobots could eliminate about 65% of the arsenic in 100 minutes, based on the 10 tests done by the researchers for the study. Pundera told ZME Science that the technology is scalable, which is why with his team he is currently in conversations with wastewater treatment companies, hoping to move the system from bench to proof-of-concept solutions.

The study was published in the journal Nature.

(c) Wyss Institute

Nanorobots made out of DNA seek and kill cancer cells

In what can only be hailed as a breakthrough in the “smart drugs” field, scientists at Harvard University have successfully managed to create nanorobots made out of strands of DNA, folded together by the DNA origami method. These act like drug-carrying recipients, which specifically target various types of cells and deliver complex molecular instructions – like telling cancer cells to self-destruct.

(c) Wyss Institute

(c) Wyss Institute

The shape and structure of the nanobots was critical to their success. The team designed a clam-like device, using DNA modelling software that can compute and complement inputted shapes with the right kinds of DNA strands, of the right helical structure and base pairs, and mix them together.

The DNA clam acts as a container and only opens when it finds its target. To keep its payload unscathed, made out specific molecules with encoded instructions for certain cell surface receptors with which it interacts, the clam is fitted with two locks. Each lock is made out of a DNA strand called an aptamer, specifically designed to recognize a certain molecule. Only when it nears the target, will the aptamer unzip, swinging the claim open, and delivering the payload in the process.

The scientists involved in research were Shawn Douglas, Ph.D., a Wyss Technology Development (Harvard University) Fellow, and Ido Bachelet, Ph.D., a former Wyss Postdoctoral Fellow who is now an Assistant Professor in the Faculty of Life Sciences and the Nano-Center at Bar-Ilan University in Israel.

To demo their creation, Douglas and Bachelet encoded antibody fragments with self-termination instructions for two types of cancer cells – leukemia and lymphoma. Since the two cancer cells communicate differently, they require specific instructions of their own, so the researchers were sure to have the messages written in different antibody combinations.

Smart DNA robots –  miracle drugs of the future?

The nanorobot for leukemia had its locks open in response to molecules expressed on the cancer cells surface, and was loaded with a single molecules which kills cells by disrupting their growth cycles. Millions of such bots were released into a mixture of both healthy and cancerous human blood cells. Only three days afterwards, half of all the cancer cells were destroyed, while absolutely no healthy cells were affected at all. The researchers claim  had they increased the number of payloads into the system, then every leukemia cell would’ve been cleansed.

What’s important to note about this particular system, whose design was heavily influenced by our own natural immune system, is that the active molecules designed to attack a specific cell can be harbored into containers featuring two types of locks. Just like the body’s immune system, the DNA origami nanobots will thus be able to hone in on specific cells in distress, bind to them, and transmit comprehensible signals to them to self-destruct. “It would require that two different signals have to be present to open it, increasing its specificity,” says Douglas.

“This work represents a major breakthrough in the field of nanobiotechnology as it demonstrates the ability to leverage recent advances in the field of DNA origami pioneered by researchers around the world, including the Wyss Institute’s own William Shih, to meet a real-world challenge, namely killing cancer cells with high specificity,” said Wyss Institute Founding Director, Donald Ingber, M.D., Ph.D. “This focus on 9translating technologies from the laboratory into transformative products and therapies is what the Wyss Institute is all about.”

By all standards, this can only be considered a remarkable research, with potentially incredible consequences in medicine. Thoughts, please?

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