A team of researchers has taken the next step in regenerative medicine, creating the first 3D-printed ovaries, using gelatin as the printer’s “ink.”

If that weren’t remarkable enough, the team also successfully implanted the ovaries into mice that were then able to ovulate, become pregnant and give birth to pups.

The revolutionary technology has so far been tested only in mice, but the research team hopes a similar technique could one day be developed for women and girls who have lost their fertility after cancer treatment, to allow them the chance to become pregnant.

The 3D-printed ovary was created by an all-female medical and engineering research team at Northwestern University.

Researchers at the Women's Health Research Institute at the university’s Feinberg School of Medicine wanted to create some kind of prosthetic ovary, or ”bioprosthesis.” The ovary needed to be able to house immature eggs as well as create follicles, which are the support cells surrounding an egg cell produce hormones needed for ovulation.

But they didn’t know how to create the actual ovary structure. So they turned to engineers from the university’s McCormick School of Engineering who offered to build an ovarian “scaffold” using a 3D printer.

For the printer’s “ink,” the team used gelatin, which is made from broken-down collagen – our bodies’ most abundant protein that gives structure to our skin, muscles, bones and more.

The gelatin was spun into filaments of hydrogel, which were laid into grids that were then interlocked together into a scaffold-like structure.

The hydrogel needed to be porous enough to naturally integrate into the mouse's body tissues, while also strong enough to support itself, since many water-based hydrogels collapse in on themselves.

After seeding the gelatin scaffolds with ovarian follicles, the team implanted the prosthetic ovaries into mice that had had their ovaries removed.

The mice successfully ovulated, became pregnant through natural mating with male mice, and gave birth to healthy pups, says Monica Laronda, the co-lead author of this research and a former post-doctoral fellow at Feinberg.

“The pups were healthy enough to be nurtured by this mom. She was able to produce milk and that process requires hormones from ovarian tissue... These pups grew to be able to either sire or become pregnant, so they were able to produce multiple generations,” she told CTV News Channel.

The researchers say the key to their success was the ovary’s grid-like structure, which allowed room for the egg cells to mature, as well as for blood vessels to form within the implant, thus enabling hormones to circulate within the mouse’s bloodstream.

The full results of the project are published in Nature Communications.

Teresa K. Woodruff, the director of the Women's Health Research Institute at Feinberg, says the project shows that it may one day be possible to bioengineer ovaries for humans.

Laronda said the idea would be to create ovaries that would could be used through every stage of the woman’s life -- puberty through a natural menopause, and give hope to kids who have survived cancer but are having trouble restoring their fertility.

“A successful bioprosthetic ovary would benefit patients with disorders of sex development… and the significant number of pediatric cancer patients who are at increased risk of hormone insufficiencies and difficulties getting pregnant,” she said.

She added we’re still years from that, “but I hope if we meet again in five years, we’ll be much closer.”