In Vitro Evaluation of Osteoblast-like Cells From Different Sources

Objectives: The aim of the study was to evaluate and compare the different behaviour of dental pulp stem cells (DPSCs), dental papilla mesenchymal cells (DPMCs) and amniotic fluid cells (AFCs) during in vitro osteoblastic differentiation.

Methods: Dental papillae and pulps were obtained respectively from germs and impacted third molars extracted in young patients for orthodontic reasons; amniotic fluid withdrawals were obtained during amniocentesis. Tissues were digested, and the cells obtained cultured, expanded, selected by a flow cytometer for their positivity to mesenchymal cells markers, and then replated in an osteogenic medium for 40 days. During this period, the expression of typical osteoblastic markers was investigated by Northern Blot and Western Blot analyses at estabilished times. Moreover, light microscope, after Alizarin Red staining, and SEM investigations were performed on cultured cells.

Results: All the cells investigated expressed the same markers, thus indicating they can successfully differentiate towards an osteoblastic pathway. However, each marker resulted more rapidly and highly expressed in AFCs than in DPSCs and DPMCs at any investigated time. Calcifying nodules could be observed at microscope analysis in all cultured population, though they appeared earlier and were more evident to Alizarin Red staining in AFCs cultures.

Conclusion: These results may confirm the greater proliferation capability of AFCs compared to DPMCs and DPSCs, their aptitude to differentiate into osteoblast-like cells and to depose a mineralized extracellular matrix, so confirming they could be successfully used in bone regeneration.