Scientists have succeeded in growing the first miniature functional model of the womb lining in a laboratory. The hope is that this technology might one day be used to provide insights into diseases such as endometriosis or even cure infertility.
Researchers at the University of Cambridge grew a miniature functional model (known as an organoid) of the uterus lining by removing tissue from patients being investigated for related conditions.
So how you actually create mini-models of the womb in a laboratory?
"We take these small clumps of cells," explains Professor Graham Burton, the lead author of the study, "then grow them in a dish by adding them into a cocktail of different factors that stimulate the proliferation of the cell." Cells in the body communicate by secreting different proteins into the surrounding fluid, Burton says, so these proteins need to be provided under laboratory conditions for the organoid to be "maintained in a proliferative state" and keep growing.
Burton's team's findings are significant because so much isn't known about the early stages of pregnancy, when the fertilized embryo implants in the womb lining, also known as the endometrium of the uterus. "These events are totally hidden from view in humans," Burton explains, "and it's really a huge black box as to what happens during the first phases of pregnancy."
By creating this part of the uterus in a lab, scientists can shine a light onto this process. "We'll be able to investigate the events that are taking place in a rigorous way, so we can see what happens during normal early pregnancy," Burton says, "but we'll also find out what's going wrong in pregnancies that miscarry or end up with growth restriction, or high blood pressure in the mother."
Until now, scientists have been restricted in their investigations of early pregnancy because the human reproductive system is so unique when compared to other animals. "It's only really the great apes that have the similar reproductive systems to humans," Burton explains, "and of course you can't experiment on those. It's been a very difficult area for scientists to study, because the formation of the placenta is particular is very different between different species."
The development offers hope for endometriosis sufferers in particular. "Endometriosis is a condition where little pieces in the uterus become displaced," Burton says, "and they go into the abdominal cavity and form little colonies of cells."
An artificial model of the womb can help scientists to understand what drives the proliferation of these cell colonies, and respond appropriately. "We'll know how they behave in different environments," he explains, "and then we'll be able to devise treatments to reduce the instances of these conditions."
Another priority is to help devise better treatments for infertility. "We know that problems of the lining of the uterus do affect fertility," Burton tells me. "But how you improve that has been difficult in the past. Now we can grow cells, we can culture cells on women experiencing different problems and see if there are therapeutic interventions that can be formed to improve the situation."
I ask whether Burton believes we'll one day be able to grow a full-sized womb lining in a lab and implant it into an infertile woman. "I think we're beginning to understand how the womb lining regenerates during the normal cycle," he responds, "and if we can understand that we may be able to understand what's going wrong in women where the lining doesn't regenerate correctly, making them infertile. But implanting that in a patient would still be a long way off."