ABSTRACT
Objective To modify polyargine (PLR) with polyethylene glycol (PEG) and to observe the effect of PEG modilication on PLR cytotoxicity and efticiency of PLR-mediated RNA interference. Methods1 HNMR was used to characterize PLR-PEG and gel electrophoresis was adopted to determine the siRNA-packing capacity of PLR-PEG. The cytotoxicity of PLR-PEG, cellular uptake and RNA interference efficiency of PLR-PEG/siRNA complexes were investigated using prostate cancer stem-like cells(RC-92a/hTERT). Results1 HNMR results showed the successful synthesis of PLR-PEG. It was found that PEG modiiication decreased cytotoxicity of PLR and reduced cellular uptake of PLR/siRNA complexes, but the reduction of cellular uptake was limited when N/P was high. The modiiication also inhibited the efticiency of PLR-mediated RNA interference, but the influence of PEG moditication was not notable within a certain range. Conclusion PEG-moditied PLR may be a promising vector for gene therapy targeting prostate cancer stem cells.
ABSTRACT
Objective To establish a high performance liquid chromatography(HPLC) method for quantitative determination of S-clopidogrel and its related substance R-clopidogrel in clopidogrel tablets, and to compare their contents between clopidogrel tablets produced by three different manufacturers. Methods An ULTRON ES-OVM column (4.6 mm × 150 mm,5 μm) was used in this study. The mobile phase consisted of a mixture of acetonitrile and 0.01 mol/L potassium dihydrogen phosphate solution (20:80). The flow-rate was 1 mL/min, with the column temperature being 17°C and the UV detection wave lenth being 220 nm. Results S-clopidogrel and its related substance R-clopidogrel were in good linear relationship within 50-117 mg/L and 1.52-30.04 mg/L, respectively (both r=0.999 8). The precision of our method was satisfactory and the average recoveries were 99.7% and 98.8%, respectively. The test solution remained stable for 12 h. S-clopidogrel and R-clopidogrel in clopidogrel tablets produced by three manufacturers were in line with the quality requirements of pharmacopoeia. Conclusion Our method is accurate and has good specificity. It can be used for the quality control of clopidogrel tablets.