When Electrospun Fiber Support Matters: In Vitro Ovine Long-Term Folliculogenesis on Poly (Epsilon Caprolactone) (PCL)-Patterned Fibers.

Current assisted reproduction technologies (ART) are insufficient to cover the slice of the population needing to restore fertility, as well as to amplify the reproductive performance of domestic animals or endangered species. The design of dedicated reproductive scaffolds has opened the possibility to better recapitulate the reproductive 3D ovarian environment, thus potentially innovating in vitro folliculogenesis (ivF) techniques. To this aim, the present research has been designed to compare ovine preantral follicles in vitro culture on poly(epsilon-caprolactone) (PCL)-based electrospun scaffolds designed with different topology (Random vs. Patterned fibers) with a previously validated system. The ivF performances were assessed after 14 days under 3D-oil, Two-Step (7 days in 3D-oil and on scaffold), or One-Step PCL protocols (14 days on PCL-scaffold) by assessing morphological and functional outcomes. The results show that Two- and One-Step PCL ivF protocols, when performed on patterned scaffolds, were both able to support follicle growth, antrum formation, and the upregulation of follicle marker genes leading to a greater oocyte meiotic competence than in the 3D-oil system. In conclusion, the One-Step approach could be proposed as a practical and valid strategy to support a synergic follicle-oocyte in vitro development, providing an innovative tool to enhance the availability of matured gametes on an individual basis for ART purposes.