Investigation of chondrogenic differentiation of placental stem cells in macromolecular crowding environment

Although stem cell treatments for regenerative medicine have been promising since they were brought to the agenda, the dreamed point has not been reached yet. When the reasons are examined, it is seen that in vitro models cannot adequately mimic the in vivo stem cell niche and the role of the extracellular matrix (ECM) has not been adequately considered. For this reason, the effects of the macromolecular crowding (MMC) approach, which is the crowding of the cell culture medium by adding macromolecules to simulate the in vivo niche, were investigated within the scope of the thesis. Carrageenan, a negatively charged sulfated polysaccharide, was used as a crowding agent to achieve this effect. Amniotic membrane mesenchymal stem cells (AM-MSCs), a type of placental stem cell, were first isolated and then extensively characterized by morphological examinations, growth curve analysis, proliferation analysis, CFU-f generating capacity, flow cytometry, and trilineage differentiation analysis. Next, cultures of AM-MSCs were maintained under two different culture conditions, i.e. standard growth and chondrogenic media conditions, and using various concentrations of MMC. The effects of macromolecular crowding and culture conditions were compared by performing phase contrast microscopy analysis, migration test, CFU-f analysis, histochemical staining and protein amount analysis. In conclusion, histochemical analyses revealed that AM-MSCs were able to proliferate under MMC conditions and differentiate into chondrogenic lineage even in the standard medium conditions. In addition, it was found that the macromolecular crowding environment reduces the capacity of cells to migrate and generate CFU-f. To our knowledge, this is the first study to examine the effects of MMCs on AM-MSCs.