Researchers at Northwestern University are celebrating the birth of several litters of baby mice that would be totally unremarkable had their mothers possessed ovaries. They did not. Instead, they were implanted with 3D-printed, gelatin-based bioprosthetic ovaries designed to ultimately restore fertility in human cancer survivors. The innovative, scalable ovaries allowed the mice to ovulate, to get pregnant, and to give birth. And the pups are all right.
“The bioprosthetic ovary restored fertility and ovarian hormone function in female mice,” Monica M. Laronda, a reproductive biologist at Northwestern University in Chicago and the coauthor of the new study published in Nature Communications, told Fatherly. Laronda cautions, however, that her team still needs to try out the transplant with larger animal models then “test this design on human ovarian follicles” to make sure the technology will work inside a human.
This is not the first report of biomaterial implants producing live pups, nor is it the first time 3D printing has helped infertile mama mice conceive. But prior techniques suffered from serious scalability problems. These methods involved encapsulating ovarian follicles–individual egg cells surrounded by hormone-producing cells–in water-based gels, which works just fine in mice, but would be unable to support the sheer number of follicles needed to restore fertility in humans. And the alternative, beefing up artificial ovaries to support more follicles, would likely make the implants less porous, preventing blood vessels from nourishing the ovarian tissue.
Laronda and colleagues set out to solve this bioengineering problem with 3D printing. Using gelatin, a relatively cheap material that biomedical researchers have favored for years, the team created a custom scaffold that could support a large number of ovarian follicles while also carving out pores that allow ample room for vascularization (the ability of blood vessels to nourish tissue).
“We have optimized the pore geometry of our 3D printed scaffold to support ovarian follicles and the open porosity allowed for vascularization and ovulation,” Laronda explains. “We chose 3D printing to design our scaffold and support the ovarian follicles because it is scalable and more readily transferable to humans than other methods.”
The researchers then implanted the artificial ovaries in mice. Laronda and her team report that the females were able to not only ovulate, but give birth to baby mice, who then, in turn, produced their own offspring. This confirmed the creation of the first 3D-printed ovary with potential to restore fertility in humans.
The findings should provide hope for the estimated 375,000 million women in the United States who are infertile due to malfunctioning ovaries, not to mention the thousands of pediatric cancer patients who suffer from fertility problems after chemotherapy racks their reproductive organs. Laronda and her team are moving forward quickly: They’re already testing their method with human follicles, refining the scaffold so it’ll pass FDA muster, and inching toward large animal tests.
They haven’t beaten infertility yet, but, thanks to 3D printing, they’re getting closer.