Design of dual targeting immunomicelles loaded with bufalin and study of their anti-tumor effect on liver cancer / 中西医结合学报

OBJECTIVE@#Bufalin is an effective drug for the treatment of liver cancer. But its high toxicity, poor water-solubility, fast metabolism and short elimination half-life limit its use in tumor treatment. How to make the drug accumulate in the tumor and reduce side effects while maintaining its efficacy are urgent problems to be solved. The goal of this study is to solve these problems.@*METHODS@#A copolymer with tunable poly-N-isopropylacrylamide and polylactic acid was designed and synthesized. The corresponding dual targeting immunomicelles (DTIs) loaded with bufalin (DTIs-BF) were synthesized by copolymer self-assembly in an aqueous solution. The size and structure of DTIs-BF were determined by ZetaSizer Nano-ZS and transmission electron microscopy. Then, its temperature sensitivity, serum stability, critical micelle concentration (CMC), entrapment efficiency (EE), drug release and non-cytotoxicity of blank block copolymer micelles (BCMs) were evaluated. Next, the effects of DTIs-BF on cellular uptake, cytotoxicity, and tumor cell inhibition were evaluated. Finally, the accumulation of DTIs-fluorescein isothiocyanate (FITC) and the in vivo anti-tumor effect were observed using an interactive video information system.@*RESULTS@#DTIs-BF had a small size, spherical shape, good temperature sensitivity, high serum stability, low CMC, high EE, and slow drug release. The blank BCMs had very low cytotoxicity. Compared with free bufalin, the in vitro cellular internalization and cytotoxicity of DTIs-BF against SMMC-7721 cells were significantly enhanced, and the effects were obviously better at 40 °C than 37 °C. In addition, the therapeutic effect on SMMC-7721 cells was further enhanced by the programmed cell death specifically caused by bufalin. When DTIs-FITC were injected intravenously in BALB/c nude mice bearing liver cancer, the accumulation of FITC was significantly increased in tumors.@*CONCLUSION@#DTIs-BF is a potentially effective nano-formulation and has broad prospects in the clinical treatment of liver cancer.

A rapid and sensitive liquid chromatography-tandem mass spectrometric method for determination of actinoside E in rat plasma and application to a pharmacokinetic study / 中国天然药物

A highly sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of actinoside E in rat plasma. The analytes were extracted by ethyl acetate and an analogue of actinoside F was used as the internal standard. The mobile phase consisted of methanol-water (50: 50, V/V) containing 0.1% formic acid was delivered at a flow rate of 0.3 mL·min(-1) to a Zorbax SB-C18 column (100 mm × 2.1 mm, 3.5 μm). The detection was performed by electrospray ionization mass spectrometry in the negative multiple reaction monitoring mode with a chromatograph run time of 3.0 min. Calibration curves of actinoside E were linear in the range of 0.5-2 500 ng·mL(-1). In this range, intra- and inter-day precision ranged from 1.7% to 7.5% and 2.0% to 8.9%, respectively. The accuracy ranged from 95.7% to 108.6%, and extraction recovery from 83.2% to 85.5%. This method was successfully applied to a pharmacokinetic study of actinoside E in rats after intravenous (5 mg·kg(-1)) and oral (100 mg·kg(-1)) administration, and the results showed that actinoside E was poorly absorbed with an absolute bioavailability being approximately 0.27%.

Dynamic effect of low frequency complex impulse current on transdermal absorption of secretio bufonis / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the regulation of transdermal absorption of Secretio Bufonis (SB) and the effect of low frequency complex impulse current (LFCIC) on it.</p><p><b>METHODS</b>By modifying three-chamber flow diffusion pool to develop a prototype LFCIC device for transdermal delivery, using high performance liquid chromatograph (HPLC) to determine the quantitative transdermal absorption of the amount of ingredients of SB, including bufalin, cinobufagin and resibufogenin, etc. and the transdermal absorption velocity was calculated.</p><p><b>RESULTS</b>The chief ingredients of SB could be absorbed through skin, but the volume was low. Additional application of LFCIC could enhance the cumulative infiltration volume and velocity of transdermal diffusion. Difference appeared 2 hrs after and significant difference appeared 4 hrs after the application, and 13.8 Hz showed the optimal effect of transdermal delivery.</p><p><b>CONCLUSION</b>Chief ingredients of SB could be absorbed through transdermal medication, and LFCIC can evidently enhance the amount and velocity of transdermal absorption of SB.</p>