SP94 Peptide-Functionalized PEG-PLGA Nanoparticle Loading with Cryptotanshinone for Targeting Therapy of Hepatocellular Carcinoma.

To achieve improved drug delivery efficiency to hepatocellular carcinoma (HCC), biodegradable poly (ethylene glycol)-poly (lactic-co-glycolic acid) (PEG-PLGA) nanoparticles (NP), surface-modified with SP94 peptide, were designed for the efficient delivery of cryptotanshinone to the tumor for the treatment of HCC. Cryptotanshinone NP and SP94-NP were prepared by using nanoprecipitation. The physicochemical and pharmaceutical properties of the NP and SP94-NP were characterized, and the release kinetics suggested that both NP and SP94-NP provided continuous, slow release of cryptotanshinone for 48 h. The in vitro cellular experiment demonstrated that SP94-NP significantly enhanced the cellular uptake of cryptotanshinone and induced high cytotoxicity and cellular apoptosis of hepatocellular carcinoma (HepG2) cells. The in vivo detecting results of targeting effect using the Cy5.5 probe evidenced that SP94-NP showed an accumulation in tumor more efficiently than that of unconjugated ones. Meanwhile, SP94-NP exhibited the smallest tumor size than other groups and showed no toxicity to body. The results of this study provide a promising nanoplatform for the targeting of HCC.

[Simultaneous determination of 6 cyclohexanedione herbicides residues in potatoes by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for analysis of 6 cyclohexanedione herbicides residues in potatoes by ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry( UPLC-MS/MS). METHODS: The target compounds in samples were extracted ultrasonically with acetonitrile. After centrifugation, the supernatant was cleaned up with Envi-carb column. The sample solution was separated on an Dionex C_(18) column( 2. 1 mm × 100 mm, 2. 2 µm) with gradient elution using acetonitrile -5 mmol/L ammonium acetate and 0. 1% formic acid in water as mobile phase. The identification was performed with tandem mass spectrometer, with electrospray ionization( ESI) in positive mode under multiple reaction monitoring. The quantification was based on external standard curves. RESULTS: The method showed good linearity in the range of 2-100 µg/L( r ≥ 0. 9923). The limit of quantitation were 2. 0 µg/kg. The detection limits of the method were 0. 6 µg/kg. The recoveries were within 67. 5%-95. 8% at the spiked levels of 2. 0-10. 0 µg/kg, and the relative standard deviations were all less than 8. 5%. Six cyclohexanedione herbicides residues were detected in 6. 7% of 30 potatoes samples which was determined by the method. CONCLUSION: The method is rapid, specific, accurate, and it is suitable for detection of quinolone and tetracycline residues.