Capsules made from algae could stop need for amputations

Capsules containing algae could stop thousands of people needing amputations, scientists believe.

The aquatic organisms, similar to plants in the garden pond, increase blood flow to damaged limbs, animal research has found.

Experts hope it will treat patients with critical limb ischaemia (CLI), which can be caused by smoking, diabetes or obesity.

Current treatment methods for CLI aim to help blood flow by widening the arteries or using a graft.

But these procedures can often fail and up to 50 per cent of people will either die or need amputation within one year. Researchers at St Thomas’ Hospital and King’s College London made the capsules from brown algae found in cold waters in the Northern Hemisphere.

Alginate from the cell walls of brown algae hold macrophages, a type of white blood cell.

Professor Bijan Modarai and his colleagues gave the algae-based capsules to mice to target areas of injured muscle tissue in their back legs.

The macrophages successfully formed new blood vessels, and as a result more blood reached the damaged area.

Scientists have been experimenting with cells as a treatment to grow arteries in the leg for years, however, these treatments have not been effective in humans.

Many of the cells injected into the injured area die, move away to surrounding areas, or are detected as ‘foreign’ by the immune system and rejected.

But the macrophages stayed in the correct place and worked effectively, according to the research funded by the British Heart Foundation.

CLI is a serious complication of peripheral arterial disease (PAD), and occurs when the arteries in the limbs become blocked as a result of a build-up of fatty deposits, reducing blood flow to the hands and feet.

CLI occurs in around one per cent of all people with peripheral arterial disease.

Currently, to treat CLI and restore blood flow in the limbs, the blocked section of the artery has to be either bypassed during surgery or widened using a small piece of expandable mesh called a stent.

However, in up to a third of patients, these methods will eventually fail or are not possible to begin with and amputation is the only option.

Modarai said: “We hope that this new method of cell therapy will greatly reduce the need for limb amputations in those people whose CLI is untreatable, and would otherwise have no other option.

“The beauty of this new algae-based treatment is that it harnesses the potential of natural materials.

“Not only does this make it a very attractive solution, but we know we can use it to safely treat people with CLI.”