“Artificial” human ovaries have been created for the first time in a breakthrough that promises hope for infertile women.
Scientists successfully grafted follicles, the precursors to eggs, onto a biological “scaffold” which then grew normally.
The development, which could be available within three years, means women with malfunctioning ovaries can look forward to getting pregnant naturally.
Currently their best option is to freeze their eggs before problems in the ovary start and then undergo potentially gruelling IVF.
The technique will be of particular benefit to female cancer sufferers whose fertility is often destroyed by radio and chemotherapy, as well as patients with multiple sclerosis and certain blood disorders.
Medics already know how to remove, cryo-preserve and then re-implant ovary tissue once harsh treatment is complete.
However, the take-up rate is very low – there have been around 100 resulting births worldwide – because of the risk the procedure will re-introduce cancer into the body.
But the new technique, revealed today at the European Society of Reproduction and Embryology annual meeting in Barcelona, strips out the cells from the ovary tissue, allowing re-implantation with no malignant risk.
Mr Stuart Lavery, a consultant gynaecologist and reproductive surgeon at Imperial College Healthcare NHS Trust, said: “It’s very exciting.
“The beauty of this is that many of the women who are having ovarian grafts can go and get pregnant naturally, and don’t need to go through IVF.
“That is a huge advantage.”
Researchers at the Rigshospitalet in Denmark removed sections of ovary from patients about to undergo cancer treatment and then cut them in half.
From one half they collected and preserved follicles.
On the other they stripped out the cells using a three-day chemical process, effectively leaving a neutral scaffold of tissue onto which the follicles were later grafted after the scaffold had been frozen in storage and then thawed.
The “artificial ovary” was then implanted into a mouse, where the follicles reached biofunctionality”, the first time this has ever been achieved.
As well as becoming pregnant through natural intercourse rather than IVF, the method means that women who have been treated for cancer should also be able to avoid an early menopause.
This is because cells around the eggs are responsible for the hormones that regulate the body’s reproductive cycle.
The technique also allows the prospect of one day starting a family to child cancer sufferers who undergo fertility-harming treatment before they are old enough to produce eggs which can be preserved.
Professor Nicholas Macklon, from the University of Southampton, said artificial ovaries could become available to patients in clinical trials within three years.
“It’s fair to say that this is early days for the work but it’s a very interesting proof of concept and I think it’s likely to develop into something that will be potentially useful,” he said.
“I think it is worth saying that studies have been done which show that when you do transfer tissue, the incidence of cancer occuring is very low, but it is still one that concerns us enough to be very cautious about it.”
Ovarian cancer and haematological cancers are thought to present the biggest risk of leaving malignant cells in frozen ovarian tissue.
Dr Suanne Pors, who presented the new research, said artificial ovaries would also make ovary donation easier, as the “decullarisation” process would removes the risk of the tissue being rejected by a recipient’s immune system.
The tissue engineering process is currently being worked on for applications in other parts of the body, including repair to damaged cardiac tissue.
The technology has already formed the basis for successful skin grafts used in cosmetic surgery and burn care.
Prof Adam Balen, former chair of the British Fertility Society, said: “This is an extremely important advance in the field of fertility preservation.
“The ability to successfully create a “new ovary” by removing any tissue that might potentially re-introduce the cancer and fashioning a scaffold on which to grow the egg-containing follicles, allows the re-implantation of a “safe” ovary, with the potential to successfully restore fertility.”