Injectable microspheres to repair failing hearts

Biodegradable microspheres can be used to deliver heart cells generated from stem cells to repair damaged hearts after a heart attack, according to new findings by UCL researchers.

This type of cell therapy could one day cure debilitating heart failure, which affects an estimated 920,000 people in the UK and continues to rise as more people are surviving a heart attack than ever before.

Scientists have been trying to use stem cells to repair damaged hearts for a number of years. However, these cells often don't remain in the heart in a healthy state for long enough to provide a sustained benefit.

Now, a UCL team, funded by the British Heart Foundation (BHF), has grown human stem cell-derived heart cells on tiny microspheres, each only a quarter of a millimeter wide, engineered from biological material. The cells attach to and grow on the microspheres, make connections with each other and are able to beat for up to 40 days in a dish. The small size of the microspheres means they can be easily injected into the heart muscle using a needle.

The researchers have also taken this one step further by developing state-of-the-art technology to visualize the injected microspheres and confirm they remain in place. Barium sulfate (BaSO4), which shines bright on X-rays and CT scans, was added to the microspheres and injected into rat hearts. Whole body CT scans confirmed that the microspheres remained in place for up to six days after injection.