The key, Laronda told Seeker, lies in two places: the gelatin used to make the ovaries, and the geometry of the scaffolding. Though it is safe to use in humans, gelatin is a tricky material to work with because it easily collapses. In previous trials, the printed gelatin became either too spread out or too clumpy. But this time, the researchers found a printing temperature where the gelatin not only remained stable, but also strong and self-supporting.
“People have printed with gelatin before,” said Laronda, “just not in this beautifully homogenous, self-supporting way.”
She and her colleagues used a 3D printer to create thin parallel ribbons of gelatin that were then offset at 60 degrees. The result “kind of looks like a stretched-out diamond,” Laronda remarked. These shapes were then stacked in groups of five to create a structure that is a mere two millimeters across.
The structures function as scaffolds capable of housing the immature mouse eggs until they are ready to be released and fertilized. They provided the maturing follicles with structural support, like the scaffolds on a building. The diamond-like shape was essential to preserve the spherical follicles, Laronda noted.
“The follicles seemed to really like something that felt snug,” she said, “but gave them room to grow.”
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The research team had been studying different scaffold models for a long time, and they were thrilled when their newest experiment worked.
“The live birth was the most exciting for us,” Laronda recalled. “It was just so prominent and clear that it worked when you have a live pup there.”
The next step is to continue testing this scaffold system in animal models, and eventually in humans. The advantage of using 3D printing, said Laronda, is that “we could easily scale up and adjust to what human follicles would need.”
Human trials remain a distant prospect for now, but the research team hopes their work will eventually be able to help women with diminished reproductive systems through all stages of their lives, from puberty to menopause.
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