Ultrasonic Powered Nanobots Remove Toxins and Bacteria from Blood

One of the most important filters in the body, the kidneys, are prone to failure. Chronic kidney disease affects 10% of the population, killing millions who do not have access to affordable treatment. It is a disease that poisons the blood, a flaw in a filter which allows waste to build up in the circulatory system.

Other blood diseases, like sepsis, one of the deadliest diseases that many have not heard about, strikes an estimated 30 million people worldwide per year. Between 15 - 30 percent cases are fatal, resulting in 6 million annual deaths - one million more casualties per year than tobacco.

The diseases are time sensitive - hours can make the difference between life or death. But diagnosing the disease and treating it with antibiotics or a dialysis machine takes hours to take effect. Experts say many of the deaths are an unnecessary result due to a lack of adequate treatment.

Cleaning the Blood with Ultrasound Powered Nanorobots

The problem is unsettling, however, engineers at the University of California, San Diego, suggests using nano-sized robots as a solution to solve the problem.

Their research, published May 30 in Science Robotics, combines the benefits of organic defense mechanisms with modern remote control systems to offer one of the most advanced, yet simple detoxification devices.

The researchers claim after treating contaminated blood with the nanorobots, the blood samples had three times fewer bacteria and toxins than untreated sample after a short 5-minute process.

Cell-sized ultrasound-powered robots - the answer to a widespread condition affecting tens of millions a year. The nanorobots swim through blood, collecting and clearing bacteria and other toxins as they move around. According to UC San Diego, the proof-of-concept nanorobots could one day provide a safe way to remove to decontaminate other biological fluids within the body.

The nanorobots are the combination of gold nanowires and a hybrid combination of platelet and red blood cells. The duo works together to perform the task of two different cells at once. Platelets, tiny blood cells that help the blood to clot, are used to bind pathogens like MRSA bacteria - an antibiotic-resistant strain of bacteria Staphylococcus aureus. The other cells, the red blood cells, are also used to help absorb and neutralize the toxins produced by MRSA bacteria.

The waves from the ultrasound also cause the gold to respond, allowing the nanobots to swim at a relatively rapid rate without the need for a chemical fuel. Increasing the mobility helps the nanobots' ability to mix with targets (the bacteria and toxins) to speed up the detoxification process.

“By integrating natural cell coatings onto synthetic nanomachines, we can impart new capabilities on tiny robots such as removal of pathogens and toxins from the body and from other matrices,” said Joseph Wang, one of the researchers who developed the technology. “This is a proof-of-concept platform for diverse therapeutic and biodetoxification applications.”

The integration of organic bio-science and nanorobotics is allowing the researchers to take advantages of the benefits of each device.

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“The idea is to create multifunctional nanorobots that can perform as many different tasks at once,” adds Berta Esteban-Fernández de Ávila, co-first author and a postdoctoral scholar in Wang’s research group at UC San Diego. “Combining platelet and red blood cell membranes into each nanorobot coating is synergistic—platelets target bacteria, while red blood cells target and neutralize the toxins those bacteria produce.”

UC San Diego also claims the bio-coating protects the nanorobots from biofouling - a process in which proteins collect on the surface of invasive foreign objects, preventing them from operating normally.

How the Nanobots Were Created

Creating a nanobot 1/25th the size of a human is a difficult task. Despite the challenge, researchers behind the blood cleaning nanorobots discovered a method to bind platelets and red blood cells. The two cells are first separated into their individual parts. Then, high-frequency sound waves are used to fuse the membranes together. Once bound, researchers then coated the hybridized membranes onto gold nanowires.

At top speed, the nanobots can travel up to 35 micrometers per second in blood. Currently, researchers are focusing on developing biodegradable materials to use instead of gold.

Though the work is still in its infancy, the results are already providing promising. Able to reduce the bacteria count and toxins in the blood by three times less in a five-minute test is a massive advancement which will very likely see live trials in the near future.