The critical micelle concentration(CMC) value and surface charge of the amphiphilic graft copolymer PECA-g-PEG micelles(PECA:polyethyl cyanoacrylae, PEG:polyethylene glycol) are reported. CMC of the copolymers is dete...The critical micelle concentration(CMC) value and surface charge of the amphiphilic graft copolymer PECA-g-PEG micelles(PECA:polyethyl cyanoacrylae, PEG:polyethylene glycol) are reported. CMC of the copolymers is determined from the absorbance change of bromophenol blue solution as function of copolymer concentration, which is about 1×10 -6 mol/L. The critical coagulation concentration (cz c) of electrolytes with different valence(z) for the copolymer micelles are examined by visual method and compared with that obtained by experiential formula cz c∝z -6. The relation formula for different cations is deduced:cz c∝z -4, which indicates the electronegative character of the micelle surface.展开更多
Methoxy poly(ethylene oxide)-b-poly(ethyl cyanoacrylate) (mPEG-b-PECA), amphiphilic block copolymer, was synthesized via oxyanion-initiated polymerization with a sodium alcoholate-terminated monomethoxy poly(ethylene ...Methoxy poly(ethylene oxide)-b-poly(ethyl cyanoacrylate) (mPEG-b-PECA), amphiphilic block copolymer, was synthesized via oxyanion-initiated polymerization with a sodium alcoholate-terminated monomethoxy poly(ethylene glycol) as the macroinitiator. mPEG-b-PECA was characterized by GPC, 1H-NMR and FTIR. The results indicate that the structure of mPEG-b-PECA is well controlled with narrow molecular weight distribution. The dexamethasone (DXM)-loaded mPEG-b-PECA nanoparticles (NPs) were prepared by the nanoprecipitation technique and characterized by LPSA, 1H-NMR and TEM. The DXM-loaded mPEG-b-PECA NPs are of spherical shape with the size of less than 100 nm. The drug-loaded amount (DL) and encapsulation efficiency (EE) of DXM-loaded NPs were investigated by HPLC. The results show that DXM can be effectively incorporated into mPEG-b-PECA NPs, which provides a potential delivery system for DXM and other hydrophobic drugs.展开更多
文摘The critical micelle concentration(CMC) value and surface charge of the amphiphilic graft copolymer PECA-g-PEG micelles(PECA:polyethyl cyanoacrylae, PEG:polyethylene glycol) are reported. CMC of the copolymers is determined from the absorbance change of bromophenol blue solution as function of copolymer concentration, which is about 1×10 -6 mol/L. The critical coagulation concentration (cz c) of electrolytes with different valence(z) for the copolymer micelles are examined by visual method and compared with that obtained by experiential formula cz c∝z -6. The relation formula for different cations is deduced:cz c∝z -4, which indicates the electronegative character of the micelle surface.
基金Supported by the Key Project of Tianjin Municipal Natural Science Foundation (Grant No. 08JCZDJC17200)Tianjin Municipal Natural Science Foundation (Grant No. 08JCYBJC01800)National Natural Science Foundation of China (Grant No. 30672554)
文摘Methoxy poly(ethylene oxide)-b-poly(ethyl cyanoacrylate) (mPEG-b-PECA), amphiphilic block copolymer, was synthesized via oxyanion-initiated polymerization with a sodium alcoholate-terminated monomethoxy poly(ethylene glycol) as the macroinitiator. mPEG-b-PECA was characterized by GPC, 1H-NMR and FTIR. The results indicate that the structure of mPEG-b-PECA is well controlled with narrow molecular weight distribution. The dexamethasone (DXM)-loaded mPEG-b-PECA nanoparticles (NPs) were prepared by the nanoprecipitation technique and characterized by LPSA, 1H-NMR and TEM. The DXM-loaded mPEG-b-PECA NPs are of spherical shape with the size of less than 100 nm. The drug-loaded amount (DL) and encapsulation efficiency (EE) of DXM-loaded NPs were investigated by HPLC. The results show that DXM can be effectively incorporated into mPEG-b-PECA NPs, which provides a potential delivery system for DXM and other hydrophobic drugs.
