A semi-living stingray may one day fix your heart

A 10-millimetre-long robot modelled on a stingray and constructed from live heart cells and gold might point to radical new therapies for cardiac patients, research reveals.

A team led by Ali Khademhosseni, a bioengineer at the University of California, Los Angeles, in the US, has created a semi-living “soft” robot that mimics in miniature the body shape and movement mechanics of a marine ray or skate.

The tiny robot moves by flapping its side fins, which like those of rays are contiguous with its front and rear ends. 

The shape of the robot presents opportunities for very efficient movement through fluid-filled environments. Perhaps of more import, however, is the fact that it comprises both living and synthetic materials.

“The development of such bioinspired systems could enable future robotics that contain both biological tissues and electronic systems,” says Khademhosseini. {%recommended 2112%}

“This advancement could be used for medical therapies such as personalised tissue patches to strengthen cardiac muscle tissue for heart attack patients.”

In a paper published in the journal Advanced Materials, Khademhosseini’s team report that the micro-ray comprises four layers of material.

At its heart – forgive the pun – is a layer of cardiac muscle cells, which are cultured and grown on a biomimetic scaffold of flexible gold microelectrodes. This is turn is placed onto two layers of micropatterned hydrogels – the first made of polyethylene glycol, and the second built from gelatin methacryloyl embedded with carbon nanotubes.

A combination of myofibre development in the tissue layer and highly localised electrical stimulation through the gold microelectrodes ensures that the living cells contract and the tiny stingray’s movement and direction can be controlled.