Vacuum-packed cell implants

Cell implants are used to treat an increasing number of conditions

Scientists have developed a way to vacuum pack cell implants so that they can be transported for use in vital hospital operations.

They have found that the cells can be kept alive for days simply by drying them and storing them in a vacuum-sealed bag.

This really pushes the frontier forward

Dr Mehmet Toner

New Scientist magazine reports that the discovery could slash the cost of cell implants designed to treat diseases such as diabetes by making it easier and cheaper to store and ship cells.

Until now, biologists thought that the body's cells had no way of protecting themselves against drying out.

Protective chemicals

Attempts to store tissues by freezing or drying have focused on adding the protective chemicals some plants and animals have evolved to protect their cells.

A team at the University of California, San Diego, led by Dr Fred Levine was trying to fine-tune a method of drying skin cells using the sugar trehalose, which preserves structures within cells as water is lost. But some cells dried this way still died.

The researchers suspected they were being killed by highly reactive chemicals called free radicals, which are generated by cells processing oxygen. So they tried vacuum sealing the dried cells in plastic bags.

Not only did it help, they also found that some cells that had been dried without trehalose also survived.

Repeated experiments have confirmed the findings.

About a third of the skin cells start growing again when rehydrated after three days at room temperature.

Weeks

A tenth survive for five days, and a few can be revived even after two weeks.

Dr Levine said: "The same is true for a variety of cells. But without a vacuum, all the cells die in three days."

Dr Mehmet Toner, a tissue engineer at Harvard Medical School in Boston, said he was surprised by the findings.

"I would have expected to see dramatic damage to cells treated this way. This really pushes the frontier forward."

Dr Levine has already successfully used the technique to ship cells across the US.

But he suspects that some protectant will be needed if most cells are to survive weeks or months rather than days.

The research is published in the journal Cryobiology.