Evaluation of a rigid fibrin matrix for the survival or isolated human preantral follicles and short-term xenografting

摘要

Introduction: Fibrin is a promising scaffold for the artificial ovary. Recently, a matrix with low fibrinogen and thrombin concentrations (12.5mg/ml and 1 Ul/ml respectively) tested for encapsulation of murine follicles showed around 30% follicle recovery rate 1 week after autotransplantation. However, when it was tested for human follicles, the results were significantly inferior. Since human ovarian cortex is more rigid than the mouse ovary, human follicles may require a stiffer matrix for their survival. This study was designed to test this hypothesis. Materials and Methods: Fresh human ovarian tissue was enzymatically digested and follicles isolated under stereomicroscope. Around 50 follicles were encapsulated in a more rigid fibrin matrix (50mg/ml fibrinogen and 50Ul/ml thrombin) and grafted to ovarian bursa of 9 nude mice. Mice were euthanized after 10 minutes (control), 2 days and 7 days, and recovered grafts analyzed at histology (every 10μm) for the presence of follicles. Only healthy looking follicles with an oocyte were counted. Results and Discussion: All grafts (3 for each grafting period) were recovered. Surprisingly, only 48% of the follicles initially embedded in the matrix were found in the control group (10min). At days 2 and 7, the follicle recovery rate was 28% and 23% respectively. Although this proportion appears to be low, it is similar to those reported by Nisolle et al., where 27% of human preantral follicles were observed after one week of xenografting of ovarian tissue. Conclusion: Our results confirm that a more rigid fibrin matrix made of higher concentrations of fibrinogen and thrombin has a positive influence on the survival of isolated human follicles. These results are very encouraging for the construction of the artificial ovary.