The application of tissue-engineering principles to the study of structure-function relationships in ovarian follicle growth and maturation has led to the development of versatile in vitro culture systems in which follicles can be studied in conditions that mimic the complex 3D environment of the ovary. The use of 3D follicle culture systems has facilitated the characterization of the cell-cell interactions and intracellular signaling events that are required for follicle growth, maturation and function as well as oocyte quality. Our alginate-based 3D culture system provides an important tool for studying how mechanical forces affect cellular responses. The culture of early-stage follicles in alginate has led to the successful development of two-layer secondary follicles and mature antral follicles that contain healthy and fertilizable oocytes. In the course of our research, we observed that follicle growth was dependent upon the concentration the alginate matrix. Two alginate preparations with specific physical properties were characterized as "permissive" or "non-permissive" to follicle development and gene products identified in each condition. These studies provide evidence that the physical environment of the ovary contributes to the function of the follicle and health of the oocyte. This work was supported by the National Institutes of Health and the Eunice Kennedy Shriver National Institutes of Child Health and Human Development, grant numbers: 5U54HD041857-07 (Northwestern University Center for Reproductive Research), UL1DE019587 (The Oncofertility Consortium), and RL1HD058295 (The Oncofertility Consortium) (platform)