Ultrasound-Controlled Nanobots can Clear out Bacteria in Blood


Microscopic nanobot kills disease-causing bacteria in the blood of a human body. / Photo by Andrey Suslov via shutterstock


Nanobots are currently under intensive research for biomedical applications. One of their potential use is smashing bacterial strains in the body. In the latest study at the University of California San Diego, engineers developed nano-sized robots that kill gram-positive bacteria.

Ending infections caused by gram-positive bacteria requires two main elements: the bacteria themselves and the toxins they produce. In order to deal with both elements, the engineers created nanobots with a size 25 times smaller than the width of human hair and coated these with gold nanowires and hybrid membranes made from a platelet and a red blood cell. 

The biological membrane allowed the tiny robots to mimic the functions of both blood cells in dealing with pathogens. Specifically, it allowed gram-positive bacteria like methicillin-resistant Staphylococcus aureus or MRSA to bind with the nanobot and have its toxins neutralized, decreasing the chance of causing a serious infection.

Meanwhile, the gold coating allowed the engineers to control and maneuver the nanobots in the body using an ultrasound machine. This way, the nanobots can swim inside the blood vessels and eliminate targeted pathogens.

“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,” explained Joseph Wang, an author of the study and a professor in the Department of NanoEngineering at UCSD.

The nanobots can travel for up to 35 micrometers per second in the blood when controlled by ultrasound. In the test that involved MRSA, the nanobots were able to reduce levels of the bacteria and the toxins in the blood within five minutes. The proof-of-concept in the study could open up opportunities for a safer and more efficient way of detoxifying bodily fluids.