Preparation And Performance Research Of Polyethyleneglycol Monoethylether2000-Grafted Soybean Phosphatidylethanolamine

As a pharmaceutical excipient, polyethylene glycol-grafted phosphatidylethanolamine ha s good application value in targeted drug delivery and drug release, but the price is expensive, which restricts its widespread application to a certain extent. The the-me of this paper is to pr epare polyethylene glycol monoethylether-grafted soybean phosphatidylethanolamine selecti ng industrial soyabean phosphatide as a source of phosphatides, and to study its self-assemble d micelles. In this thesis three parts are reported the synthesis of carboxyl-monomethoxypoly(ethylene glycol) and polyethylene glycol monoethylether2000-grafted soybean phosphatidyle thanolamine, and the preparation and properties of the micelles of polyethylene glycol monoet hylether2000-grafted soybean phosphatidylethanolamine.This experiment used mPEG with the molecular weights of1200,2000and5000as raw materials and adopted the Jones reagent oxidation method to produce CmPEG at ambient temperature. Characterized by1HNMR and IR, the product was proved to be CmPEG. The carboxyl conversion rate was taken as the index to find out that the most proper molar ratio of CrO3and mPEG was2to1. The carboxyl conversion rates of three products with different molecular weights were99.63%,99.4%and98.0%respectively. This experiment adopted the solid-liquid extraction technique to reprocess these products and taked the appearance and color as indices. The result shows that the product is produced to be white and of high purity in the order of distilling acetone first and adding sodium bicarbonate to neutralize them next. Taking the yield of these products as the index, used mPEG with the molecular weights of1000,1200,2000,5000and PEG with the molecular weights of800as raw materials, the experiment shows that this method applies to the preparation of the carboxylic acid derivatives of PEG which molecular weight is more than2000and mPEG which molecular weight is more than1000. The yield of these five products with different molecular weights are88.2%,93.5%,98.0%,98.2%,39.1%respectively.To prepare polyethylene glycol monomethyl2000ether chloride with high activity using carboxyl-monomethoxypoly(ethylene glycol) as raw materials, and then polyethylene glycol monoethylether2000-grafted soybean phosphatidylethanolamine is prepared by reaction of it and soyabean phosphatide.The product structure have been characterized by1HNMR and IR. The product yield is85.2%when the mass ratio of soyabean powdered phosphatide and polyethylene glycol monomethyl2000ether chloride is3:1, reaction time is4h, the reaction temperature is45℃and dosage of triethylamine is3ml.The micelles of polyethylene glycol monoethylether2000-grafted soybean phosphatidylethanolamine were prepared, the diameter of micelles of product formed in aqueous solution was observed by TEM, the dynamic stability of the product was characterized by studying the critical aggregation concentration of through fluorescence probe technique, the dynamic stability of product was characterized by emulsifying power. The results showed that:the diameter of micelles of product formed in aqueous solution was between30-80nm, the critical micelle concentration is2×10-6mol/L, the thermodynamic stability of micelles was superior to that of small molecule, and the dynamic stability of the product was better than that of soyabean powdered phosphatide.