Human ovarian tissue cultures: extracellular matrix composition, coating density and tissue dimensions.

Human ovarian tissue can be successfully cryopreserved for fertility preservation. Optimal use of this approach requires the development of reliable restoration methods, including in-vitro culture of follicles. A culture system has been established, but improvement of the basic handling and techniques is necessary. Ovarian biopsies were collected from 33 women, cut into small pieces and cultured for 7-14 days on an extracellular matrix. Three separate studies investigated tissue dimensions (slices and cubes), coating density of extracellular matrix (diluted, thin and thick), and different extracellular matrix compositions (regular Matrigel, growth factor reduced Matrigel and laminin). Initial recruitment of primordial follicles and reduction in follicle viability was observed in all cultures compared with uncultured tissue. After 7 days of culture, more viable follicles were present in the cubed tissue, which also showed significant activation of growth, observed in tissue slices only after 14 days of culture. A diluted coating of Matrigel supported a greater proportion of viable follicles in 7-day cultures, whereas composition of the extracellular matrix had no effect. Human ovarian follicles can grow and develop in vitro within cortical tissue, and may benefit from culture as cubes on diluted Matrigel. This technique may provide a solution to the successful recovery and growth of follicles from frozen human ovarian tissue even though it will take time and much more optimization before it can be used in clinical practice.