ABSTRACT
@#Gas chromatography-mass spectrometry (GC-MS) method was established for trace analysis of the potential genotoxic impurity chlorocyclohexane in trihexyphenidyl hydrochloride bulk drug, utilizing an RXI-5SIL MS column at isothermal temperature of 60 °C for the entire 6-minute run time.The inlet temperature was 180 °C and a split ratio of 10∶1 was used with the injection volume of 1.0 μL.The selective ion monitoring mode was set at m/z 82 for chlorocyclohexane with a detector voltage of 0.3 kV and an ion source temperature of 240 °C.The method was verified with respect to specificity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision and robustness.Good linear correlation was achieved with coefficient r of 0.999 9 in the concentration range of 59.72-493 ng/mL.The intra- and inter-day precision was satisfactory (RSD ≤ 5.0%) and robust (RSD ≤ 1.65%).The proposed method in this study can be adequately adopted as a tool for quality assurance of trihexyphenidyl hydrochloride in routine test of potential genotoxic impurity.
ABSTRACT
@#A Mn-clusters-porphyrin metal-organic framework nanosheet(nMn-MOF)was synthesized by coordination chelation to enhance photodynamic therapy. The nanosheet was characterized by dynamic light scattering, transmission electron microscopy and X-ray photoelectron spectroscopy. Oxygen sensor and ICG were used to investigate the production of oxygen and the singlet oxygen(1O2)generation. The cytotoxicity of the nanosheet against tumor cells were detected by CCK-8 assay, and the anti-hypoxia and oxygen-generation ability of nanosheets were investigated by fluorescence staining assay. The results indicated that this nanosheet could catalyze the intracellular H2O2 into O2, which overcame the tumor hypoxia. Furthermore, the generated oxygen was converted to cytotoxic 1O2 under the near infrared light irradiation, thereby enhancing photodynamic therapy.
ABSTRACT
@#Abstract:Photodynamic therapy(PDT)is a minimal invasive therapy that have been clinically approved for the cancer treatment with selective cell toxicity. When activated by appropriate wavelength of light, photosensitizers transfer the absorbed photon energy to the surrounding molecular oxygen to generate reactive oxygen species, which result in cell death, vessel damage and immune activation of tumor site. This paper summarize the main challenges and recent solutions for PDT application, such as the low tissue penetration of light, toxicity induced by nonspecific accumulation of skin and poor PDT effect of hypoxia tumor.