Extracellular-like matrices and leukaemia inhibitory factor for in vitro culture of human primordial follicles

The possibility of maturing human primordial follicles in vitro would assist fertility restoration without the danger of reseeding malignancies. Leukaemia inhibitory factor (LIF) and certain culture matrices may promote human follicular growth. The present study compared human primordial follicular growth on novel culture matrices, namely human recombinant vitronectin (hrVit), small intestine submucosa (SIS), alginate scaffolds and human recombinant virgin collagen bioengineered in tobacco plant lines (CollPlant). The frozen-thawed ovarian samples that were used had been obtained from girls or young women undergoing fertility preservation. In the first part of the study, 20 samples were cultured for 6 days on hrVit or SIS with basic culture medium alone or supplemented with one of two concentrations of LIF (10ngmL-1 and 100ngmL-1), with and without LIF-neutralising antibody. In the second part of the study, 15 samples were cultured for 6 days on alginate scaffolds or CollPlant matrices with basic culture medium. Follicular development was assessed by follicular counts and classification, Ki67 immunohistochemistry and 17β-oestradiol and anti-Müllerian hormone measurements in spent media samples. Primordial follicular growth was not enhanced by LIF. Despite some significant differences among the four matrices, none appeared to have a clear advantage, apart from significantly more Ki67-stained follicles on alginate and CollPlant matrices. Further studies of other culture matrices and medium supplements are needed to obtain an optimal system.