Engineers have developed tiny ultrasound-powered nanorobots that can swim through blood, removing harmful bacteria and the toxins they produce.These proof-of-concept nanorobots could one day offer a safe and efficient way to detoxify and decontaminate biological threat agents.
This would provide an fast alternative to the multiple, broad-spectrum antibiotics currently used to treat life-threatening pathogens like MRSA bacteria (an antibiotic-resistant staph strain). MRSA is considered a serious worldwide threat to public health.
ntimicrobial resistance (AMR) threatens the effective prevention and treatment of an ever-increasing range of infections caused by bacteria, parasites, viruses and fungi, according to the World Health Organization, an increasingly serious threat to global public health.
The researchers coated gold nanowires with a hybrid of red blood cell membranes and platelets (tiny blood cells that help your body form clots to stop bleeding)
The platelets cloak the nanowires and attract bacterial pathogens, which become bound to the nanorobots.
The red blood cells then absorb and neutralize the toxins produced by these bacteria.
The interior gold nanowire body of the nanorobots responds to ultrasound, causing the nanorobots to swim around rapidly (no chemical fuel required), mimicking the movement of natural motile cells (such as red blood cells). This mobility helps the nanorobots efficiently mix with their targets (bacteria and toxins) in blood and speed up detoxification.
The coating also protects the nanorobots from a process known as biofouling, when proteins collect onto the surface of foreign objects and prevent them from operating normally.
The nanorobots are just over one micrometer, (1,000 nanometers) long (for comparison, red blood cells have a diameter of 6 to 8 micrometers). The nanorobots can travel up to 35 micrometers per second in blood when powered by ultrasound.
In tests, the researchers used the nanorobots to treat blood samples contaminated with MRSA and their toxins. After five minutes, these blood samples had three times less bacteria and toxins than untreated samples.