A rapid, sensitive and simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the simultaneous determination of yogliptin and its metabolite in Wistar rat plasma. Linagliptin and dexamethasone were chosen as the internal standards of yogliptin and its metabolite, (R)-8-(3-hydroxypiperidine- -yl)-7-(but-2-yn-1-yl)-1-((5-fluorobenzo[d]thiazol-2-yl)methyl)-3-methyl- H-purine-2, 6 (3H, 7H)-dione, respectively. After a simple protein precipitation using acetonitrile as the precipitating solvent, both analytes and ISs were separated on a Grace Altima HP C18 column (2.1 mm x 50 mm, 5 microm) with gradient elution using methanol (containing 0.1% formic acid, 4 mmol x L(-1) ammonium acetate)-0.1% formic acid (containing 4 mmol x L(-1) ammonium acetate) as the mobile phase. A chromatographic total run time of 4.4 min was achieved. Mass spectrometric detection was conducted with electrospray ionization under positive-ion and multiple-reaction monitoring modes. Linear calibration curves for yogliptin and its metabolite were over the concentration range of 0.5 to 500 ng x mL(-1) with a lower limit of quantification of 0.5 ng x mL(-1). The intra- and inter- assay precisions were all below 14%, the accuracies were all in standard ranges. The method was used to determine the concentration of yogliptin and M1 in Wistar rat plasma after a single oral administration of yogliptin (27 mg x kg(-1)). The method was proved to be selective, sensitive and suitable for pharmacokinetic study of yogliptin and M1 in Wistar rat plasma.

The colonization of microorganisms planted on the surface of teeth and restoration materials is the main cause of oral disease and treatment failure. How to improve the antibacterial properties of dental materials is a hot topic in dentistry. Nano-sized antibacterial materials have attracted much attention. Among them, metal and metal oxide nanoparticles are prominent due to their strong and broad-spectrum antibacterial activity. Thus, in recent years, many studies have used metal and metal oxide nanoparticles to develop antimicrobial dental materials for resin restoration, root canal therapy, orthodontic treatment, and implant surface and removable denture repair and have found that the antibacterial properties of nano-sized materials are significantly enhanced. However, the mechanical properties and esthetic properties of the modified materials are affected, so it is still necessary to explore appropriate modification methods. In addition, most of the experiments are carried out in vitro, which cannot accurately simulate the oral environment. Therefore, the antibacterial effect, cytotoxicity and immune response of these materials in vivo still need further research and exploration. This paper reviewed the potential antibacterial mechanisms and the safety of those nanoparticles and their applications in dentistry.