Characterization of PEG and Cholesterol Side Chain Containing Amphiphilic Copolymer Micelles and Copolymer- Liposome Conjugates

• Main Authors: Ming-hung Hsieh, 謝明宏
• Other Authors: 陳 崇 賢
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/38374120680040843394

碩士 === 國立臺灣科技大學 === 化學工程系 === 91 === Amphiphilic graft copolymers comprising hydrophobic cholesterol side chains and hydrophilic PEG side chains were investigated. CMC decreases with decreasing hydrophobicity of theae copolymers. The colloidal stability of all polymeric micelles is quite satisfactory, as illustrated by the particle size versus time data. The copolymer-liposome complex also shows good colloidal stability because of the electrostatic and steric repulsion forces associated with the copolymer-modified liposomes. The encapsulation efficiency of copolymers was determined by 1H-NMR. The copolymer comprising more hydrophilic monomeric units has the lower encapsulation efficicency. The reagent 5(6)-CF was used as a model compound to study the permeability of the liposome bilayer. The larger the total amount of hydrophilic side chains, the higher the bilayer permeability. Pyrene loading were used to study the bilayer structure of liposomes. The IE/IM became higher accompanied with lower amount of inserted cholesterol. Small angle neutron scattering is used to analyze the liposome scattering. The polycore-shell model fits the experimental data reasonably well. The shell of the copolymer- liposome complex should contain the monomeric units of HEMA. Attractive and repulsion forces between these colloidal partices,steric repulsion effect was the greatest in the system of polymer micelle suspension. The copolymer-liposome complex can decrease the attractive force between these partices and then reduse the fusion and aggregation in the liposome suspension.