Researchers at Brown University have created an “artificial human ovary” using a tissue engineering approach that they hope will one day allow scientists to mature human eggs in a laboratory.
In the near term, an artificial ovary will enable researchers to better explore the impact of environmental toxins or fertility-enhancing substances on human fertility. It could also aid the development of new forms of contraceptives and the study of ovarian cancer.
Further down the line, it could also help women whose ovaries are damaged because of chemotherapy, radiation, or illness, according to a paper published in the current issue of Journal of Assisted Reproduction and Genetics. Today, those women have limited opportunities for childbirth: either a hurried in-vitro fertilization cycle that leads to a handful of frozen eggs, or freezing ovarian tissue in the hopes that healthy eggs will someday be able to be matured.
An artificial ovary, where immature eggs could be harvested by the thousands and then matured at will in the laboratory, would open up huge possibilities for the one in a 1,000 women who need it, says the paper’s first author, Stephan Krotz, who was a graduate student at Brown when he worked on the paper.
The artificial ovary marks the first time researchers have successfully created a three-dimensional environment that contains the three main types of ovarian cells: theca cells, granulosa cells, and the eggs, known as oocytes. The paper’s lead researcher is Sandra Carson, a professor of obstetrics and gynecology at Brown and Woman and Infants Hospital of Rhode Island.
Alan B. Copperman, director of infertility at Mt. Sinai Medical Center in New York, says clinical benefits are years and many scientific hurdles away, but he’s impressed by the research potential of the group’s work. “The concept of creating an artificial three-dimensional environment, and the fact that we can take out immature eggs and let them grow and mature into viable eggs, is really exciting,” he says.
Copperman says the artificial ovary could serve as a model to help researchers better understand the ovarian aging process, the focus of much of his research. “If we can establish a viable testing environment, we can learn more about how to optimize eggs, and discriminate good from bad eggs.”
The Brown researchers’ innovation was using a honeycomb-shaped mold to support the egg. Human eggs are too large to be grown without some kind of support structure. “If you try to grow it by itself, in a dish, it basically collapses on itself,” says Krotz, now a reproductive endocrinologist and fertility specialist at the Advanced Fertility Center of Texas.