Tooth development is controlled by body plan during the fetal period, the generation of teeth from tooth germ is induced by the epithelial-mesenchymal interaction. Spatiotemporal regulation of tooth morphogenesis is supported by gene expression. Although many of the genes involved in tooth development are known, the molecular mechanism underlying tooth morphogenesis is not completely understood. For a comprehensive understanding of tooth development, the elucidation of unknown genes is necessary. In this study, to identify unknown genes involved in tooth development, we performed genome-wide analysis at each stage of tooth development and identified 17 genes with high levels of expression and large changes in expression. In addition, we performed qPCR and in situ hybridization analyses to elucidate the spatiotemporal regulation, such as the regulation that occurs around or in the entire tooth germ, enamel knots, epithelium, and mesenchyme. These results show that these characteristic genes may play important roles in each time period or region of tooth development, and the elucidation of the functions of these genes will lead to an integrated understanding of the process of tooth development.
Carbon nanotubes (CNTs) release substantial vibrational energy after exposure to near-infrared (NIR) irradiation. This study examines the preparation of exothermic complexes comprising CNTs, DNA, and protamine (CNT/DNA-protamine complexes), and evaluates the complex membrane for use as a barrier membrane in guided bone regeneration (GBR). Heat generation of the CNT/DNA-protamine complex membrane increased with amount of CNTs in the complex, and the temperature increase reached 16–17.6°C after irradiation for 4 min. The degradation rate of the complex membrane immersed in PBS was influenced by the amount of CNTs and was lower than that of DNA-protamine complexes (DP complexes) used as a control. The CNT/DNA-protamine complexes showed higher resistance to compressive deformation than DP complexes. The results of this study suggested that CNT/DNA-protamine complexes may be candidate biodegradable membranes with controllable heat generation and an adjustable degradation rate for use in GBR.