Characteristics of stem cells from human exfoliated deciduous teeth (SHED) from intact cryopreserved deciduous teeth.

The aim of this study is to compare the characteristics of stem cells derived from human exfoliated deciduous teeth (SHED) from cryopreserved intact deciduous teeth with those of fresh SHED. In total, 20 exfoliated deciduous teeth were randomly divided into a fresh group (f-SHED; n = 11) and cryopreserved group (c-SHED; n = 9; stored for 1-8 months). Following thawing and separation of the pulp, the SHED cells were cultured, and the characteristics as mesenchymal stem cells were investigated using proliferation assays, cell-cycle analysis, colony-forming unit-fibroblast (CFU-F) assays, and flow cytometry analyses. Furthermore, differentiation into adipogenic and osteogenic lineages was investigated in vitro as well as in vivo via transplantation in mice. We found no significant differences between the two groups in the proliferation analyses, in the expression of mesenchymal stem cell markers, or in the adipogenic and osteogenic differentiation in vitro (p < 0.05). Furthermore, the in vivo transplantation results showed no significant differences in the quantity of bone tissue that formed or in histochemistry performance (p < 0.05). In conclusion, cryopreservation of intact exfoliated deciduous teeth appears to be a useful method for preserving SHED.

The fabrication of TiO2 mesoporous thick films by employing a pre-embedded ZnO nanorods support.

TiO2 mesoporous films with a thickness more than 2 microm were synthesized through the evaporation-induced self-assembly approach. In order to prevent the formation of cracks due to the strain during the calcination, we employed the ZnO nanorod arrays as a pre-embedded support, which were obtained from an aqueous solution method. The spaces between ZnO nanorods were filled with TiO2 sol-gel by a dip-coater. Then ZnO nanorods embedded in the thick film were eliminated by a wet chemical etching method and the left spaces were refilled by the TiO2 sol-gel. As a result, a dense and thick TiO2 mesoporous film was obtained. The resultant materials were characterized in detail by using small angle X-ray diffraction (SAXRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy methods (TEM).