Overview of methods of isolation, cultivation and genetic profiling on human umbilical cord stem cells

Abstract Stem cells possess unique properties, such as self-renewal ability or differentiation capacity into more specialized cells, which makes them particularly relevant for regenerative medicine and cellular therapies. Although embryonic stem cells (ESCs) are capable of differentiation into all cell lineages, their utilization is associated with ethical concerns since they are obtained from embryos. Furthermore, ESCs may form teratomas or cause immune rejection in the clinical setting. Therefore, an effort has been made to utilize stem cells derived from adult tissues, especially mesenchymal stem cells (MSCs). A particularly attractive source of MSCs is the human umbilical cord, which is typically discarded after birth and considered a medical waste, therefore the acquisition of the cells is not associated with any health risk for a patient. Moreover, umbilical cord-derived MSCs do not express MHCII, thus they exhibit reduced immunogenicity. MSCs have been isolated from all compartments of umbilical cord, however the Wharton’s jelly-derived MSCs (WJ-M-SCs) are the most clinically utilizable. There are two techniques of UC-MSCs isolation: the enzymatic and explant procedures. The explant method involves cell outgrowth of tissue pieces placed into plastic culture vessel after mechanical splitting, whereas the enzymatic technique involves minced tissue digestion in an enzymatic solution. In vitro culture conditions of the isolated cells are highly variable among the researchers, however the most commonly performed molecular assays are homogenous and include: RT-qPCR, flow cytometry and immunocytochemistry. Running title: Human umbilical cord stem cells isolation, cultivation and genetic profiling