Aim To improve the stability and optimize the tissue distribution of Evans blue liposome in rats, some surfactants such as DSPE-PEG, Tween80, and Brij35 were used to modify the Evans blue liposome. Methods The Evans b...Aim To improve the stability and optimize the tissue distribution of Evans blue liposome in rats, some surfactants such as DSPE-PEG, Tween80, and Brij35 were used to modify the Evans blue liposome. Methods The Evans blue liposome was prepared by the reverse-phase-evaporation method. The effect of cholesterol on the encapsulation percentage of Evans blue was studied. The effects of DSPE-PEG, Tween80, and Brij35 on the encapsulation percentage and tissue distribution of Evans blue liposome in the rat were determined. Results The top encapsulation percentage of Evans blue liposome is 25.30%. After modification by DSPE-PEG, Tween80, and Brij35, the encapsulation percentages decreased slightly, but not significantly. After modification, the Evans blue concentrations deceased in the liver, spleen, lung and kidney, but increased in the brain, especially in the EB-L-Tween80 group. Conclusion DSPE-PEG, Tween80, and Brij35 have slight effect on the encapsulation percentage of Evans blue liposome. The effect of Brij35 on the distribution of Evans blue liposome is similar to that of DSPE-PEG because they both is prevent the reticuloendothelial system (RES) from clearing liposome. The Evans blue concentration in the brain is greatly improved when Tween80 is used to modify the EB liposome, which is good information for preparing liposome targeting the brain.展开更多
The pseudo-quaternary phase diagram of Brij35/sodium oleate/oleic acid/watersystems has been investigated, and the liquid crystal area has been identified, which covers abouttwo thirds of the whole phase diagram. The ...The pseudo-quaternary phase diagram of Brij35/sodium oleate/oleic acid/watersystems has been investigated, and the liquid crystal area has been identified, which covers abouttwo thirds of the whole phase diagram. The liquid crystal structure and behavior have been alsostudied by using polarizing texture, small angle X-ray scattering, ~2H-NMR and rheometer etc. Theresult shows that when the composition of the system changes along the line of AA′ in this largeliquid crystal region, the structural change iscubic→cubic/lamellar→lamellar→larnellar/hexagonal→hexagonal. Meanwhile, we made the firstattempt of systematic study of the rheological properties of the above system. The lattice constantsof cubic and hexagonal liquid crystals are 10.53 and 5.68 nm, respectively.展开更多
Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at...Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at a concentration of 100 times the critical micellar concentration (cmc) give direct evidence that the hydrophilic polyoxyethylene chains, staying in the exterior of the micellar core, are coiled, bent and aligned around the micellar core with a certain number of water molecules included. This hydrophilic layer is in contact with the solvent, water, keeping the micellar solution stable. 1H NMR relaxation time measurements show that the first oxyethylene group next to the alkyl chain participates in the formation of the surface area of the micellar core. The motion of the hydrophilic polyoxyethylene chains is less restricted as compared with the hydrophobic alkyl chains.展开更多
文摘Aim To improve the stability and optimize the tissue distribution of Evans blue liposome in rats, some surfactants such as DSPE-PEG, Tween80, and Brij35 were used to modify the Evans blue liposome. Methods The Evans blue liposome was prepared by the reverse-phase-evaporation method. The effect of cholesterol on the encapsulation percentage of Evans blue was studied. The effects of DSPE-PEG, Tween80, and Brij35 on the encapsulation percentage and tissue distribution of Evans blue liposome in the rat were determined. Results The top encapsulation percentage of Evans blue liposome is 25.30%. After modification by DSPE-PEG, Tween80, and Brij35, the encapsulation percentages decreased slightly, but not significantly. After modification, the Evans blue concentrations deceased in the liver, spleen, lung and kidney, but increased in the brain, especially in the EB-L-Tween80 group. Conclusion DSPE-PEG, Tween80, and Brij35 have slight effect on the encapsulation percentage of Evans blue liposome. The effect of Brij35 on the distribution of Evans blue liposome is similar to that of DSPE-PEG because they both is prevent the reticuloendothelial system (RES) from clearing liposome. The Evans blue concentration in the brain is greatly improved when Tween80 is used to modify the EB liposome, which is good information for preparing liposome targeting the brain.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 30370945) Guizhou Provincial Governor Foundation (No. 6, 2001).
文摘The pseudo-quaternary phase diagram of Brij35/sodium oleate/oleic acid/watersystems has been investigated, and the liquid crystal area has been identified, which covers abouttwo thirds of the whole phase diagram. The liquid crystal structure and behavior have been alsostudied by using polarizing texture, small angle X-ray scattering, ~2H-NMR and rheometer etc. Theresult shows that when the composition of the system changes along the line of AA′ in this largeliquid crystal region, the structural change iscubic→cubic/lamellar→lamellar→larnellar/hexagonal→hexagonal. Meanwhile, we made the firstattempt of systematic study of the rheological properties of the above system. The lattice constantsof cubic and hexagonal liquid crystals are 10.53 and 5.68 nm, respectively.
基金This work was supported by the National Key Basic Research Development Program "Fundamental Studies of the Extensively Enhanced Petroleum Recovery" (Grant No. G199022504) .
文摘Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at a concentration of 100 times the critical micellar concentration (cmc) give direct evidence that the hydrophilic polyoxyethylene chains, staying in the exterior of the micellar core, are coiled, bent and aligned around the micellar core with a certain number of water molecules included. This hydrophilic layer is in contact with the solvent, water, keeping the micellar solution stable. 1H NMR relaxation time measurements show that the first oxyethylene group next to the alkyl chain participates in the formation of the surface area of the micellar core. The motion of the hydrophilic polyoxyethylene chains is less restricted as compared with the hydrophobic alkyl chains.
