Yes, stem cells can proliferate in cellular cultures. The blood of the umbilical cord has at least two populations of stem cells: Hematopoietic stem cells and pluripotent cells, that can be transformed into osteosytes, chondrocytes, muscle cells, neural cells, hepatocytes or pancreatic cells. The hematopoietic stem cells comprise the most mature population and have the limit of three cellular divisions, before apoptosis. The rest of the population is presented more immature and can be divided up to 40 times without cell atypias or differentiation. For all the above reasons hematopoietic stem cells proliferation is not used today for raising the number of hematopoietic stem cells, very useful to treat leukemias in cases of low number of cells and increased weight of the patient. The cell proliferation can be applied to the immature population of cells, (pluripotent) either to rises the number of cells or to differentiate in other cell types, useful in the regenerative medicine.
Biohellenika applies a special method to the placenta that aims to the collection of the largest possible number of stem cells with a natural way, without the necessary use of cell proliferation. This method is published in the Transplantation Proceedings Journal, Tsagias et al 2007 and is referred to the collection of the remained stem cells in the placenta’s extended network of vessels that can not are extracted with the classical initial selection. Sometimes the number of the collected cells finally, is double.