Comparative characterization of stem cells from human exfoliated deciduous teeth and dental pulp stem cells

Objective: This study focused on the characterization of stem cells from human exfoliated deciduous teeth (SHED) in comparison with dental pulp stem cells (DPSCs) to certify SHED as a key element in tissue engineering. Methods: In the present study, SHED and DPSCs were assayed for their cell surface antigens and proliferation by measuring the cell cycles, growth rates, Ki67-positive efficiencies, and colony-forming units (CFUs). The evaluation of multi-differentiation was performed using alizarin red and oil red O and real-time PCR in vitro. The mineralization capability of the cells was examined in vivo by implanting with ceramic bovine bone (CBB) into subcutaneous of immunocompromised mice for 8 weeks. A three-dimensional pellet cultivation system is proposed for SHED and DPSCs to recreate the biological microenvironment that is similar to that of a regenerative milieu. Results: SHED showed a higher proliferation rate and differentiation capability in comparison with DPSCs in vitro, and the results of the in vivo transplantation suggest that SHED have a higher capability of mineralization than the DPSCs. The mRNA expression levels of inflammatory cytokines, including matrix metalloproteinase-1 (MMP1), tissue inhibitors of metalloproteinase-1 (TIMP1), matrix metalloproteinase-2 (MMP2), tissue inhibitors of metalloproteinase-2 (TIMP2) and interleukin-6 (IL-6) were higher in SHED than that in DPSCs. In addition, the expression levels of Col l and proliferating cell nuclear antigen (PCNA) in SHED sheets were significantly higher than those in DPSCs sheets. Conclusions: This study systematically demonstrated the differences in the growth and differentiation characteristics between SHED and DPSCs. Consequently, SHED may represent a suitable, accessible and potential alternative source for regenerative medicine and therapeutic applications. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.