Idiopathic scoliosis (IS) is the most common spinal deformity diagnosed in childhood or early adolescence, while the underlying pathogenesis of this serious condition remains largely unknown. Here, we report zebrafish ccdc57 mutants exhibiting scoliosis during late development, similar to that observed in human adolescent idiopathic scoliosis (AIS). Zebrafish ccdc57 mutants developed hydrocephalus due to cerebrospinal fluid (CSF) flow defects caused by uncoordinated cilia beating in ependymal cells. Mechanistically, Ccdc57 localizes to ciliary basal bodies and controls the planar polarity of ependymal cells through regulating the organization of microtubule networks and proper positioning of basal bodies. Interestingly, ependymal cell polarity defects were first observed in ccdc57 mutants at approximately 17 days postfertilization, the same time when scoliosis became apparent and prior to multiciliated ependymal cell maturation. We further showed that mutant spinal cord exhibited altered expression pattern of the Urotensin neuropeptides, in consistent with the curvature of the spine. Strikingly, human IS patients also displayed abnormal Urotensin signaling in paraspinal muscles. Altogether, our data suggest that ependymal polarity defects are one of the earliest sign of scoliosis in zebrafish and disclose the essential and conserved roles of Urotensin signaling during scoliosis progression.
This study investigated the mechanical properties and antibacterial properties of hexagonal boron nitride and titanium dioxide (h-BN-TiO2) nanocomposite modified traditional glass ionomer cement. The mechanism of formation of the h-BN-TiO2 nanocomposite was elucidated by conducting molecular dynamics (MD) simulations using the Material Studio (MS) software. Furthermore, synthesis of h-BN-TiO2 nanocomposite by the original growth method using hexagonal boron nitride nanosheets (h-BNNs) and titanium dioxide nanoparticles (TiO2 Nps) and characterization using TEM and AFM to determine their particle sizes, morphologies, and structures. The mechanical properties and antibacterial efficacies of the glass ionomer cement composites were analyzed based on the different mass fractions (0, 0.3, 0.7, 1.1, and 1.5 wt%) of the h-BN-TiO2 nanocomposite. The results showed when the concentration of the h-BN-TiO2 nanocomposite was 1.1 wt%, the Compressive strength (CS) and Vicker hardness (VHN) were 80.2% and 149.65% higher, respectively, compared to the glass ionomer cement without any h-BN-TiO2 nanocomposite. Also, the increase in the concentration of the h-BN-TiO2 nanocomposite led to a decrease in both the coefficient of friction (COF) and solubility, but a 93.4% increase in the antibacterial properties of the glass ionomer cement composites. The cell survival rate of each group was more than 70% after 48 h, but the difference was not statistically significant (p > 0.05). Therefore, the h-BN-TiO2 nanocomposite served as a reinforcing material for glass ionomer cement, which can be useful in clinical dentistry and provide a new strategy for improving the clinical utility of glass ionomer cement.
Robust and antibacterial dental resin is essential for repairing the shape and function of the teeth. However, an ingenious way to achieve the synergistic enhancement of these two properties is...
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