Liu Min-Chao,Liu Bing,Sun Xiang-Yu,Lin Hui-Chao,Lu Jia-Zheng,Jin Shu-Fang,Yan Si-Qi,Li Yan-Yu,Zhao Ping
The dose-dependent toxicity and low specificity against cancerous cells have restricted the clinical use of daunomycin (DNM). Titanium dioxide (TiO2) has been wildly used as an inorganic photodynamic therapy (PDT) agent and drug carrier. To facilitate the targeted drug delivery
and combined therapy, in the present study, TiO2-coated Fe3O4 nanoparticles (Fe3O4@TiO2 NPs) were employed to load DNM and the drug-loaded Fe3O4@TiO2-DNM Nps exhibited smart pH-controlled releasing
and satisfactory cytotoxicity as well as photocytotocity. The combination of prussian blue staining and fluorescence methods evidenced the effortless cell internalization of the fabricated Fe3O4@TiO2-DNM Nps for the cancer cells. The cell cycle status experiments
indicated that the as-prepared nanospheres arrested the S and G2/M periods of the cancer cell proliferation in the dark, and further induced the apoptosis under the irradiation of ultraviolet light. The cell apoptotic results revealed that the apoptosis induced by the Fe3O4@TiO2-DNM
Nps was in the early stage. The constructed Fe3O4@TiO2-DNM NPs have been endowed with multifunctions that allow them to selectively deliver combinatorial therapeutic payload and exhibit integrated therapeutic effectiveness to tumors.
With the increasing demand for lipase inhibitors and new drugs used in the clinical treatment of obesity, it is of great significance to screen lipase inhibitors from traditional Chinese medicines (TCMs) via capillary electrophoresis. In this work, Fe 3 O 4 @TiO 2 nanoparticles was fabricated by solvothermal method and employed as an improved magnetic support to immobilize lipase through electrostatic interaction. By the method of transmission electron microscopy, fourier transform infrared spectroscopy and X-ray diffraction, the magnetic nanoparticles were characterized. The immobilized enzyme possessed advantages of a wider range for pH and temperature endurance, better storage stability and reusability. The kinetics performances of the immobilized lipase were studied. When p-Nitrophenyl palmitate (pNPP) was used as enzyme substrate, the Michaelis-Menten constant was calculated to be 2.51 mM and its inhibition constant for Orlistat was ascertained to be 13.41 μM. Ultimately, the established method was applied to lipase inhibitors screening from 6 Tibetan medicines with lipase inhibitory activity and Oxytropis falcate Bunge was screened out for its supreme lipase inhibitory activity. 11 compounds in the Oxytropis falcate Bunge were further screened, five compounds exhibited similar inhibitory activity to Orlistat, and one compound (kaempferol) presented better inhibitory activity than Orlistat, which is the most commonly used drugs to treat obesity in clinic. This work not only developed a method for new anti-obesity drugs discovery, but also provided inspiration for exploring new medicinal value of the TCMs.
危险品化学品经营许可证（带存储）