Background and Aims: Bone marrow-derived mesenchymal stem cells (BM-MSCs) are a well-known source of multipotent adult stem cells. Despite using different methodologies of MSCs preparing for clinical applications, the top safest procedure to manipulate these cells, has not yet been determined. Recently, ex-vivo expansion of MSCs for their subsequent implantation, using some biological product, is suggested instead of fetal bovine serum (FBS). Previous studies have shown the effect of follicular fluid (FF) (a dynamic fluid in ovarian follicle) as an additive component in cell culture. Hence, this study aimed to decipher its role on the human BM-MSC proliferation.
Materials and Methods: In this study, BM-MSCs at 3^rd passage were cultivated in the presence of 20% FF (group I), 10% FF+ FBS 10% (group II) and FBS 20% as control group. The capacity of proliferation as calculating population doubling times and gene expression levels of stem cell factor, stromal cell-derived factor 1, and transforming growth factor beta were analyzed in osteogeneic media to examine the impacts of FF on osteogenesis of MSCs.
Results: Our results corroborated an up-regulatory effect of FF on the proliferation of BM-MSCs by shorter population doubling times in the group II of treated cells and an increase in gene expression level of osteocalcin and transforming growth factor beta in the presence of higher concentrations of FF in cell culture  FF 20% and 10%, respectively.
Conclusions: FF is a potent mitogen for cell proliferation. FF may be an efficient substitution of FBS in ex-vivo cell culture, eliminating zoonotic infections and immunological reactions.