​New York, Nov 18 (IANS) Cuts or bruises in older adults take a longer time to heal as compared to youngsters as a result of a disruption in communication between their skin cells and immune system, researchers have found.

Wound healing is one of the most complex processes to occur in the human body. Both skin cells and immune cells contribute to this elaborate process, which begins with the formation of a scab. 

The new skin cells -- known as keratinocytes -- gather under the scab to fill in the wound, the study said. 

"Within days of an injury, skin cells migrate in and close the wound, a process that requires coordination with nearby immune cells. Our experiments have shown that, with ageing, disruptions to communication between skin cells and their immune cells slow down this step," said Elaine Fuchs, Professor at The Rockefeller University, New York.

The researchers found that in older mice keratinocytes were much slower in their travels, while in younger mice they sent a signalling protein to immune cells which increased the healing speed. 

When the same protein was applied to old mouse skin tissue, it boosted the communication.

"This discovery suggests new approaches to developing treatments that could speed healing among older people," Fuchs added.

In the study, the team focused on healing in two-month-old versus 24-month-old mice -- roughly equivalent to 20- and 70-year-old humans. 

They found that among the older mice, keratinocytes were much slower to migrate into the skin gap under the scab, and, as a result, wounds often took days longer to close.

The study will help to develop drugs to activate pathways that help ageing skin cells to communicate better with their immune cell neighbours, Fuchs said, in the paper described in the journal Cell.