Alginate Made Core-Shell S tructure for In Vitro Cultureof Ovine Preantral Follicles

Background: Despite significant advances in the field of threedimensional(۳D) culture of the ovarian follicles, it is s till farfrom the natural follicle environment in the ovary. ۳D sys tem isnot successful in the translation of ovarian mechanical heterogeneityinto the culture. Numerous s trategies such as creatingovarian micro-tissue mimicking ovarian cortex-medulla havebeen applied to resemble mechanical heterogeneity. For this,we create a core-shell s tructure using two different concentrationsof alginate for In vitro culture of ovine preantral follicles.Materials and Methods: Medium size ovine preantral follicleswere isolated mechanically and enzymatically and encapsulatedin ۱% alginate (core group) for ۱۷ days as a control. Tocreate a core-shell s tructure, ۱% alginate as the core and ۱.۵%alginate as the shell were applied. The follicles were loaded betweencore and shell. At the end of the culture, survival rate andantrum formation rate were assessed.Results: Degenerated follicles in the core-shell group (۳۸.۳%)were higher than in the core group (۱۴%) (P˂۰.۰۵). In the coreshellcultures, follicles flattened and spread between two layers.Follicles encapsulated in the core-shell s tructure had anantrum formation rate of ۵۸.۶% as compared to ۵۹.۸% in thecore group.Conclusion: Although developing to the antral s tage wasachieved in both groups, due to the higher degeneration rate,the core-shell s tructure made from alginate is not a desirables tructure for implying mechanical heterogeneity. To improvethe core-shell s tructure, other biomaterials especially biodegradableones should be inves tigated.