Blood cell-sized robots to diagnose, treat illness in hard-to-reach body parts

Scientists have developed a swarm of robots measuring about the size of a blood cell that can be remotely operated to diagnose and treat illness in hard-to- reach areas of the human body.

The robots, manufactured by coating tiny algae with magnetic particles, can be tracked in tissue close to the skin's surface by imaging the algae's natural fluorescence, and in hard-to-reach deeper tissue by magnetic resonance imaging (MRI).

In tests, a swarm of robots a few millionths of a metre in length were guided magnetically to sites in the stomach of rats.

Researchers, led by those from Chinese University of Hong Kong, developed micro-robots by coating a microscopic algae with non-harmful, biocompatible magnetic particles.

The devices were tested in the stomach of rats and can smoothly swim in biological fluids, such as dilute blood and gastric fluid, according to the study published in the journal Science Robotics.

Scientists, including those from Universities of Edinburgh and Manchester in the UK, suggest that the advance may lead to a way to deliver drugs to parts of the body that are otherwise difficult to treat.

The robots could also sense chemical changes linked to the onset of illness within parts of the body, which makes them potentially useful as probes for remote diagnosis.

The time taken for the robots to function and biodegrade within the body could be tailored by adjusting the thickness of their manufactured coating.

In lab tests, the devices were found to release potent compounds from the algae core during degradation, which selectively attacked cancer cells while leaving healthy cells unharmed.

Further research could show whether this might have potential as a treatment, researchers said.