The prosthetic ovary consists of a printed scaffold that carries ovarian follicles (egg precursor cells), sourced from natural donor ovaries. From the Nature a

The prosthetic ovary consists of a printed scaffold that carries ovarian follicles (egg precursor cells), sourced from natural donor ovaries. From the Nature article: https://www.nature.com/articles/ncomms15261 https://www.nature.com/articles/ncomms15261 > Two mice with sham controls and seven mice with bioprosthetic ovaries were mated with males who had previously sired pups. Three bioprosthetic ovary recipients had litters of one or two pups each, while none of the sham controls had pups. Of the litters produced, at least one pup per litter was confirmed to have resulted from an egg ovulated from the implant.