Human umbilical cord blood was collected from healthy women aged between 20 and 40 years with informed consent and according to the protocol approved by Institutional Review Board of Baqiyatallah University of Medical Sciences. Thereafter, human umbilical cord blood was transferred into Falcon tube containing phosphate buffered saline (PBS) without Ca2+ or Mg2+ supplemented with 2.5 µg/ml fungizone, 100 µg/ml streptomycin, 100 U/ml penicillin, and 0.5 Mm ethylenediaminetetraacetic acid (All from Merck, Germany). Mononuclear cells were separated utilizing Ficoll-Hypaque (Sigma, St. Louis, MO) density gradient centrifugation and washed out in PBS. Thereafter, the cell pellet in the tube was suspended in Dulbecco's modified Eagle medium and Ham’s F-12 (DMEM-F12) medium supplemented with 10% fetal bovine serum (FBS; All from Sigma) and cultured in tissue culture plates. The cells were kept in the 37℃ incubator with 5% CO2 and saturated humidity. After removing nonadherent cells in the second day of incubation, the culture of adherent cells continued until 70% confluency (Dasari et al., 2007; Faramarzi et al., 2016). At Passage 4, the cells were checked for the properties of mesenchymal stem cells using fibronectin (+), CD44 (+), and CD45 (−) (Santa Cruz Biotechnology, Santa Cruz, CA) immunostaining. The dissociated mesenchymal cells were further dispersed in 10% FBS-DMEM and counted under a microscope with the aid of a hemocytometer. The mesenchymal cells were then utilized directly for cultures or stored in liquid nitrogen for later use.