A colour change that might save your skin

Chameleon bandage
Courtesy Mike McRae, CSIRO Science by email

From CSIRO Science by email. Your body’s covering has to protect your gooey bits from the environment. Not only does it serve as a way to keep your tissues and organs from drying out, it acts as a wall stopping microbes from setting up an all-you-can-eat restaurant inside you. To do this well it has to grow quickly, especially when it gets cut.

Sometimes unfortunate accidents occur and it helps to cover broken skin with a clean, sterile material – such as a bandage – to stop too many microbes from getting inside. This usually buys the body more time to heal itself. In some cases, however, the body doesn’t repair itself quite so easily. Conditions such as diabetes make it hard for the skin to knit together again, allowing the body’s coating of bacteria to move into a new environment and establish an infection. In these cases, bandages can hide the symptoms of an infection until damage has been done, hindering as much as helping the healing process.

A CSIRO researcher studying for her PhD at Monash University has discovered a way to mix a colour-changing chemical into fibres to create a bandage that turns blue as it warms. Such a material could provide people with a useful way of knowing how their wounds are healing without having to take a peek. As microbes multiply in a wound, the body responds by opening nearby capillaries, sending more blood (and more microbe-gobbling white blood cells) to the site. The reproducing bacteria and increased blood flow makes infected wounds slightly warmer than the rest of the body. This is a useful early indication that a wound might be turning nasty. Such technology would mean patients could watch their bandages for colour changes and see their doctor quickly if an infection sets in, rather than waiting for their injury to show more worrying symptoms that it has gone bad.