Cancer-fighting robots thinner than hair

ROBOTS one-thousandth the width of a human hair are now able to fight cancer by targeting tumours in the body.

Scientists have built nano-robots from DNA sheets shaped into tubes which are injected into the bloodstream.

The tubes carry a blood-clotting enzyme, thrombin, and are painted with proteins which home in on a separate proteins found only in tumour cells.

When the robots reach their target and bind to its surface, they spring open and deliver the enzyme, which clots the blood supply to the tumour and causes it to die.

The nanorobots were found to be safe in tests on mice and pigs, with no evidence of spreading to the brain where they could cause a stroke.

The treatment blocked tumour blood supply within 24 hours, without effecting healthy tissue.

Three out of eight mice with skin cancer saw their tumours shrink, with their cancer survival time more than doubling on average from 20.5 to 45 days.

The research comes after a team of scientists, involving Durham University, last year created nanorobots able to drill into and destroy cancer cells.

Nanorobots are so-called because of their tiny size and because they contain parts capable of movement within the body.

Baroness Delyth Morgan, chief executive of Breast Cancer Now, said: ‘The development of nanorobots that can deliver drugs to a target within a tumour is an exciting glimpse into the future of cancer medicine.

‘This is the first time that DNA molecules have been manipulated to deliver drugs in this way – a fascinating advance that, if refined and proven effective in humans, could have far-reaching implications for treating cancer and other diseases.’

Professor Hao Yan, a co-author of the study from Arizona State University, said: ‘We have developed the first autonomous, DNA robotic system for a very precise drug design and targeted cancer therapy.’

One sheet of newspaper is around 100,000 nanometres thick. The nanorobots used to fight cancer are made from sheets of DNA measuring 90 nanometres by 60.

The research, led by the National Centre for Nanoscience and Technology in China, is published in the journal Nature Biotechnology.