ABSTRACT
ABSTRACT:Objective To prepare polymeric nanomicelles capable of simultaneously loading doxorubicin (DOX) and Bcl‐2 small interfering RNA (Bcl‐2 siRNA ) , and to explore their in vitro cytotoxicity and cellular uptake in MCF‐7 human breast cancer cells .Methods Copolymer poly (ethylene glycol )‐g‐polyethylenimine‐g‐poly(γ‐benzyl‐L‐glutamate) was synthesized by the combination of reductive amination and carbodiimide methods , and its chemical structure was verified by 1 H NMR .Empty and drug‐loaded copolymeric nanomicelles were prepared by dialysis method and characterized by transmission electron microscope and dynamic light scattering .The ability of the nanomicelles to compress Bcl‐2 siRNA was measured by by agarose gel electrophoresis method . The release profiles of DOX and Bcl‐2 siRNA from the nanomicelles were explored by means of fluorescence spectrometry and dialysis method .The in vitro cytotoxicity and cellular uptake of DOX and Bcl‐2 siRNA co‐loaded nanomicelles in MCF‐7 human breast cancer cells were characterized by MTT assay and confocal laser scanning microscopy , respectively .Results The critical micelle concentration of the copolymer was about 4 mg/L ,and the sizes of self‐assembled empty and drug‐loaded nanomicelles were smaller than 200 nm .The drug‐loading efficiency and drug‐loading content of DOX in the nanomicelles were 88 .7% and 15 .1% ,respectively .The DOX‐loaded nanomicelles could efficiently compress Bcl‐2 siRNA when an N/P ratio was ≥64 .The zeta potential of DOX and Bcl‐2 siRNA co‐loaded nanomicelles was +30 mV .The release behavior of the cargoes from the nanomicells was pH‐sensitive , and the release of Bcl‐2 siRNA was more sensitive to acidic pH than that of DOX . The nanomicelles could simultaneously deliver DOX and Bcl‐2 siRNA into MCF‐7 cells , and the co‐delivered DOX and Bcl‐2 siRNA significantly increased the cytotoxicity of DOX (P<0 .05) .Conclusion The polymeric nanomicelles can co‐load DOX and Bcl‐2 siRNA and deliver them into MCF‐7 cells , and DOX in combination with Bcl‐2 siRNA can synergistically inhibit the growth of MCF‐7 cells and promote cell apoptosis ,suggesting that the nanomicells may be a promising carrier for the co‐delivery for chemotherapeutics and genes .
ABSTRACT
Objective To investigate the effects and mechanisms of rosiglitazone on the expressions of nuclear factor-κB and matrix metalloprotease (MMP-9) in peripheral blood monocyte-derived macrophages (MDMs) in patients with coronary heart disease. Method This was a clinical case-control study. Forty-eight actue coronary symdrome (ACS) patients (ACS group), and 20 patients with stable angina (SA) (control group) were collected. They were performed coronary arteriography in the Department of Cardiology of the Second Xiangya Hospital from March to April in 2007. Exclusion criteria included acute infection, trauma or surgery patients within four weeks, cerebral vascular accident, liver and kidney dysfunction, cancer, and so on. The peripheral blood mononuclear cells were isolated and transformed into MDMs with macrophage colony-stimulating factor treatment. The transformed MDMs were randomly assigned into subgrougs and incubated with 0 /μmol/L, 1 μmol/L, 10 μmol/L, 20 μmol/L of rosiglitazone respectively. The expressions of PPAR-γ mRNA, MMP-9 mRNA were determined by RT-PCR and nuclear factor-κB P65 (NF-KB P65) expression by immunohistochemistry. Multiple comparisons were examined for significant differences using analysis of variance (ANOVA). Results The basal expression of PPAR-y mRNA was lower, in contrast, the levels of NF-KB P65 and MMP-9 mRNA were higher in ACS group than control group. PPAR-γ mRNA expression were significantly upregulated in both ACS and control groups with rosiglitazone treatment. PPAR-γ mRNA expression was positive correlation, while the expressions of MMP-9 mRNA were negative correlation with the rosiglitazone concentration in the ACS group. Rosiglitazone inhibited the expression of NF-KB in a concentration-independent manner in ACS and control groups. Conclusions The expression of PPAR-y mRNA is inhibited, while the activity of NF-KB and expression of MMP-9 mRNA are enhanced in MDMs of ACS cases. Rosiglitazone intervention may inhibit NF-KB activity and MMP-9 expression by upregulation of PPAR-y expression in MDMS of patiens with ACS.