Researchers at the University of California, San Diego have developed cell-like nanorobots that can clear bacteria and bacterial toxins from blood. The tiny bots are powered by ultrasound and they could pave the way for nanorobotic systems that can decontaminate biological fluids or even clear infections in the body. Despite being 25 times smaller than the width of a human hair, the nanorobots can travel through blood at speeds of up to 35 micrometers a second when stimulated using ultrasound.
The research team developed the nanorobots by coating gold nanowires in a hybrid cell membrane that combines components from red blood cell and platelet membranes. As platelets can naturally bind pathogenic bacteria in the blood, such as MRSA, and red blood cells can absorb bacterial toxins, the hybrid membrane on the nanorobots can effectively target both bacteria and their toxins.
The gold nanowires at the heart of the nanorobots respond to ultrasound, helping to rapidly propel the devices through blood without the need for a chemical source of energy. This rapid movement helps the nanorobots to mix with the blood more effectively, meaning they are more efficient in mopping up contaminants.
“The idea is to create multifunctional nanorobots that can perform as many different tasks at once,” said Berta Esteban-Fernández de Ávila, a researcher involved in the study. “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.”
So far, the researchers have tested the nanorobots in blood samples that were contaminated with MRSA. After just 5 minutes of treatment, the samples contained three times less bacteria and toxins. While these particular nanorobots are likely more suited to decontaminating biological fluids rather than clearing infection in the body, they could pave the way for clinical nanorobotics. The researchers are planning tests in live animals in the future, and also intend to find a biodegradable alternative to the gold nanowires so that the nanorobots are more suited to clinical applications.
See a video of the researchers discussing the nanorobots below.
Study in Science Robotics: Hybrid biomembrane–functionalized nanorobots for concurrent removal of pathogenic bacteria and toxins…