Laura Ritchie is 53-year-old diabetic mother of two from Aberdeen. In 2010 low blood sugar caused her to lose consciousness in the bath and lie for six hours with her left leg under the running hot tap. In hospital, doctors twice attempted skin grafts but the huge wound failed to heal; Mrs Ritchie was told several times that her leg may need to be amputated. But a revolutionary new treatment then became available in Scotland that allows doctors to literally spray new skin onto wounds, thanks to a technology called ReCell.
The procedure begins by scraping a sample of skin just 0.15mm deep from an area the size of a postage stamp, leaving behind a ‘rug burn’ with pinprick bleeding. The sample contains basal stem cells and melanocytes (cells that give skin its colour and texture). These are placed into a solution that dissolves the bonds between the cells using trypsin, an enzyme harvested from pigs. The resulting mixture is sprayed back onto the patient’s burn site, where the stem cells and melanocytes divide and expand. In under a week the cells grow into as much as a page’s worth of new skin – between 20 and 80 times the original stamp-sized area. The overall time taken to heal is 12-13 days, no longer than for traditional skin grafts.
This technique offers many benefits. A regular graft cuts deeper, requiring more anaesthetic, and leaves the patient bleeding over a much wider area: grafting a page’s worth of skin means removing a page’s worth first. And that page must be taken from elsewhere on the body, where the skin may look and feel different. The ReCell skin, by contrast, grows naturally – avoiding stretching or scarring – and the small donor site means it can be sampled close to the burned area so the new skin will match the old.
ReCell can also be used when grafts cannot, such as for a patient who has lost too much skin, grafts from another person lead to a high risk of rejection (doctors often cannot prescribe immunosuppressant drugs because the patient is already too vulnerable to infection), while growing new skin in a lab is slow and expensive. 500cm2 of skin takes two weeks to grow and costs up to $2000, while the ReCell solution is ready in an hour and costs around $200 per kit.
Though not yet commonly used, ReCell is licensed for use in Europe, Asia, Australia and Canada and is undergoing clinical trials in the USA, where it is being sponsored by the military. If the technology gains worldwide adoption its impact could be significant: the WHO estimates 195,000 people die from burns and resulting infections each year, and those who survive using grafts can be disfigured or left permanently disabled.
For proof of the treatment’s effectiveness we need not look far. In Aberdeen, one grateful mother has started to walk again after a course of ReCell and shockwave therapy. “I had had all the usual treatments … [they] had gone on for so long it was wearing no matter how positive I tried to be,” says Mrs Ritchie. “With that and the pain I hadn’t much fight left, so without these new treatments I would have lost my leg for sure.”