In vitro interaction of deferiprone with cellular membrane transporters of hOCTs and hOAT1 / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a LC-MS/MS method for determination of deferiprone in cell lysate and to study the potential interaction between deferiprone and hOCTs or hOAT1 transporters in vitro.</p><p><b>METHODS</b>The determination was performed on an Agilent Eclipse Plus C18 column(3.5 μm, 2.1 mm×50 mm).The gradient mobile phase was composed of solvent A:0.1% formic acid in water, and B:0.1% formic acid in acetonitrile. The mass spectrometer with an electrospray interface was operated in positive ion mode with multiple reaction monitoring (MRM) scan mode monitored the ion pair of deferiprone at m/z 140→96, or phenacetin at m/z 180→110. The effects of deferiprone on the accumulation of typical substrates of hOCTs and hOAT1 were evaluated by MDCK-hOCTs and MDCK-hOAT1 cells respectively. The accumulation of deferiprone was also investigated in MDCK-hOCTs cells and mock cells with or without typical inhibitors.</p><p><b>RESULTS</b>The standard curve was linear over the range of 5-300 nmol/L. The assay recovery of deferiprone was above 94%, and the intra-day precision (RSD) was less than 2.0%. The accumulation of MPP(+) in MDCK-hOCTs cells with 300 μmol/L deferiprone were 73.5%, 87.1% and 70.4%, respectively. The uptake of deferiprone in MDCK-hOCTs and mock cells did not show significant difference. Deferiprone of 100 μmol/L did not significantly affect the accumulation of 6-CF in MDCK-hOAT1 cell.</p><p><b>CONCLUSION</b>The method is sensitivity and suitable for the determination of deferiprone in cell lysate. Deferiprone can significantly inhibit hOCT1 and hOCT3, but has no effects on hOCT2 and hOAT1. hOCTs may not play a major role in the transport of deferiprone.</p>

Roles of angiotensin Ⅱ receptors in tumor / 国际肿瘤学杂志

Angiotensin (Ang Ⅱ),a main effector peptide of the renin-angiotensin system (RAS),mediates a hormonal action in the maintenance of blood pressure and electrolyte levels,and thus fluid homeostasis.Recent studies have implicated that it correlates with tumor growth,angiogenesis,metastasis and it has drawn more and more attention.Many studies show that Ang Ⅱ-AT1R/AT2R play crucial roles in tumor growth,metastasis,invasion and tumor angiogenesis,which are formed new targets for treating malignant tumors.

Anticancer effect of triptolide-polyethylenimine-cyclodextrin in vitro / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a drug delivery system triptolide-polyethylenimine-cyclodextrin and to evaluate its anticancer activity in vitro.</p><p><b>METHODS</b>Triptolide was conjugated to polyethylenimine-cyclodextrin by N, N'-carbonyldiimidazole to form triptolide-polyethylenimine-cyclodextrin. (1)H-NMR, FT-IR and XRD were used to confirm its structure. The anticancer effect of the polymer was assessed by MTT assay, erasion trace test and hematoxylin-eosin staining. The potential to condense siRNA and to delivery siRNA into cytoplasm was demonstrated by gel retardation assay, zeta-potential determination and fluorescence staining.</p><p><b>RESULTS</b>Triptolide was successfully conjugated to polyethylenimine-cyclodextrin and the conjugation rate of triptolide was 10% (w/w). siRNA was effectively condensed by the polymer at the N/P ratio of 5, and its particle size was 300 ±15 nm and zeta potential was 8 ±2.5 mV. MTT assay, erasion trace test and hematoxylin-eosin staining revealed that triptolide-polyethylenimine-cyclodextrin had anticancer effect and low cytotoxicity to normal cells. The polymer was able to deliver siRNA to the cytoplasm effectively as demonstrated by fluorescence staining.</p><p><b>CONCLUSION</b>Triptolide-polyethylenimine-cyclodextrin is able to inhibit the growth and migration of cancer cells in vitro and to carry siRNA into cells effectively. It is potential to be used as a novel prodrug for co-delivery of gene and drug in cancer treatment.</p>

Characteristics of cationic polymers PEI-CyD, PEI-PHPA, PEE-PHPA and PEI25kD in vitro and in vivo / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To study the characteristics of cationic polymers polyethylenimine-β-cyclodextrin (PEI-CyD), polyethylenimine-poly-(3-hydroxypropyl)-aspartamide (PEI-PHPA), N,N-Dimethyldipropylenetriamine-Bis(3-aminopropyl)amine-aspartamide (PEE-PHPA) in vitro and in vivo.</p><p><b>METHODS</b>PEI-PHPA, PEI-CyD and PEE-PHPA were synthesized and the chemistry structure of PEI-PHPA, PEI-CyD and PEE-PHPA was confirmed by (1)H-NMR. The particle size and zeta potential of these polymers were measured, and capacity of plasmid DNA condensation was tested. The inhibition of COS-7, A549, HEK293 and C6 cells was measured by MTT assay. The transfection efficiency was determined in HEK293 cell lines. The toxicity, tissue distribution and transfection efficiency of cationic polymers were tested in vivo.</p><p><b>RESULTS</b>When the N/P of polymers/DNA at 30, the particle sizes were close 250 nm and the zeta-potential were near 35 mv. They were able to condense DNA at N/P ratio < 5. The MTT assay showed that the IC(50) of PEE-PHPA was 21.5, 20.2, 7.30 and 37.1 μg/ml, and that of PEI25kD was 15.8, 18.3, 11.4 and 36.7 μg/ml in C6, COS-7, A549 and HEK293cell lines, respectively. The cell viability of PEI-CyD and PEI-PHPA in above cell lines was over 60%. They had high transfection efficiency in HEK293 cell lines. The LD(50) of PEI25Kd, PEI-CyD, PEI-PHPA and PEE-PHPA in vivo was 19.50, 100.4, 521.2 and 630.0, respectively by intraperitoneal (ip) injection. The contractions of these polymers were higher in kidney than in other organs and tissues.PEE-PHPA had slight effect on kidney and liver function.</p><p><b>CONCLUSION</b>PEE and PEI25kD have higher transfection efficiency and higher toxicity; while PC and PHPA-PEI have lower toxicity and higher transfection efficiency to be used as non-viral gene vector.</p>

Target-controlled infusion of remifentanil and propofol during operation with suspension laryngoscopy / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate target-controlled infusion (TCI) of remifentail-propofol and the balanced anesthesia of fentanyl-isoflurane during the operation with suspension laryngscope.</p><p><b>METHODS</b>Sixty ASA I-II patients scheduled for the surgery through suspension laryngoscopy were randomly divided into two groups: TCI group and control group. In TCI group, anesthesia was maintained with TCI remifentanil-propofol which was stopped at the end of operation. The target plasma concentration of remifentanil was set at 6 microg/L and propofol at 3 mg/L. In control group, anesthesia was induced with intravenous fentanl 2.5 microg/kg and propofol 1-2 mg/kg, maintained with fentanl 0.03 microg.kg(-1). min(-1) and 1% isoflurane which was stopped at the end of surgery. Intubation was facilitated with succinylcholine 1-1.5 mg/kg.MAP, HR, ECG, S(p)O(2) and P(ET)CO(2) were monitored during anesthesia. The following parameters were recorded and compared between two groups: (1) the changes in blood pressure (BP), heart rate(HR) and S(p)O(2) at different time point; (2) recovery profile including the time of response to verbal commands, autonomous breathing, tracheal extubation, orientation recovery, discharging from PACU after operation; (3) OAAS scores after operation; (4) postoperative complications; (5) unexpected events and awareness during operation.</p><p><b>RESULT</b>(1) The hemodynamics were stable while the target plasma concentration of remifentanil was set at 6 microg/L and propofol at 3 mg/L. (2) During tracheal intubation, suspension laryngoscope was inserted, and extubation MAP was significantly lower in TCI group than that in control group; (3) There were no significant differences in hemodynamic values and S(p)O(2) of different time points between two groups. Study group was faster than control group on recovery profile including the time of response to verbal commands, autonomous breathing, tracheal extubation, orientation recovery and discharging from PACU. There was respectively one unexpected event in both groups.</p><p><b>CONCLUSION</b>Remifentanil supplemented with isoflurane anesthesia can achieve the optimal hemodynamic stability during the operation with suspension laryngoscopy and better recovery profile from anesthesia than fentanyl.</p>