Implantable Ovary Bioprosthesis Holds Promise for Restoring Fertility
Oocyte in ovarian follicle
BOSTON — Results from a study in mice showed that an implantable 3D-printed ovary bioprosthesis may have the potential to restore fertility in women, according to research reported at ENDO 2016.
This potential implant may be particularly beneficial for women who have undergone treatment for cancer, explained lead study author Monica M. Laronda, PhD, a postdoctoral research fellow at Northwestern University's Feinberg School of Medicine.
“Because of our success in modern medicine, approximately 85% of children who undergo cancer treatment survive longer than 5 years, which is significant and a clear indication of long-term survival,” she said during a press conference. These numbers indicate that about 1 in 250 adults in the United States have survived some sort of childhood cancer.
“However, the way we that we go about eradicating cancer is through radiation and chemotherapy treatments,” Dr Laronda said. “These often have off-target effects … like the reduction of sex hormone production and reduced fertility or infertility as these patients get older.”
Current options to preserve and restore fertility in women include hormone treatments to increase oocyte production and cryopreservation, or alternatively, a woman could have her oocytes fertilized and then cryopreserved as embryos. However, these choices are not beneficial for women undergoing aggressive cancer treatment, those who cannot withstand a month-long hormone induction, or those who have hormone-responsive cancers.
Additionally, these options are not feasible for young pediatric patients who do not produce eggs because they have not yet gone through puberty. In this case, one option is an experimental procedure to remove a piece of the ovary or remove a whole ovary because at this point in time, a young girl will have a large ovarian reserve as well as the most potential egg cells in this ovarian tissue than she will have in the future.
“When we think about this problem, we want to think of the materials that we have — that we're able to cryopreserve and how can we restore that sex hormone and her fertility later on in life,” said Dr Laronda, which is how they conceived of an ovary bioprosthesis.
To create this prosthesis, the researchers needed to develop a scaffold that would be mechanically rigid so that it could withstand the implantation process and that would also have a 3D feel. This, noted Dr Laronda, is essential because the potential egg cell is surrounded by a layer of nerve cells or a layer of supportive cells in a spherical shape, and these connections with those cells are essential to the development of the potential egg cell to become an ovulated, fertilizable egg. The bioprosthesis also required open pores for nutrient growth and needed to accommodate growth of the egg.