Nanorobots clean blood
Image: Coloured SEM image of nanorobots coated in hybrid platelet/red blood cell membranes. [Esteban-Fernández de Ávila/Science Robotics]
Researchers at the US-based University of California San Diego have developed ultrasound-powered robots that swim through blood to remove harmful bacteria and toxins.
Stunning SEM imagery provides insight to these proof-of-concept nanorobots that could offer a safe and efficient way to detoxify and decontaminate biological fluids.
Professor Joseph Wang from NanoEngineering at UC San Diego Jacobs School of Engineering and colleagues fabricated the nanorobots by coating gold nanowires with a hybrid of platelet and red blood cell membranes.
This hybrid cell membrane coating allows the nanodevices to perform the tasks of platelets, which bind bacteria, as well as red blood cells, which absorb and neutralise the toxins produced by these bacteria.
Crucially, the gold body of the nanorobots responds to ultrasound, which gives the devices the ability to 'swim' around rapidly without chemical fuel.
The hybrid coating also protects the nanorobots from biofouling.
SEM image of a MRSA bacterium attached to a hybrid cell membrane coated nanorobot. [Esteban-Fernández de Ávila/Science Robotics]
"We have demonstrated ultrasound-propelled biomimetic nanorobots consisting of gold nanowires cloaked with a hybrid of red blood cell membranes and platelet membranes," writes Wang in Science Robotics. "The nanorobots displayed rapid and efficient prolonged acoustic propulsion in whole blood, with no apparent biofouling, and mimicked the movement of natural motile cells."
“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,” he adds. “This is a proof-of-concept platform for diverse therapeutic and biodetoxification applications.”
The aim of the research is to create multi-functional nanorobots that can perform different tasks at the same time.
The latest devices can travel up to 35 micrometres per second in blood, when powered by ultrasound.
In tests, researchers used the nanorobots to treat blood samples contaminated with MRSA and related toxins.
After five minutes, these blood samples had three times less bacteria and toxins than untreated samples.
Researchers note that the ultimate goal is not to use the nanorobots specifically for treating MRSA infections, but more generally for detoxifying biological fluids.
Future work includes tests in live animals, and the team is also working on making nanorobots from biodegradable materials instead of gold.
Research is published in Science Robotics.
- The research combines technologies pioneered by Joseph Wang and Liangfang Zhang, professors in the Department of NanoEngineering at the UC San Diego Jacobs School of Engineering. Wang’s team developed the ultrasound-powered nanorobots, and Zhang’s team invented the technology to coat nanoparticles in natural cell membranes.