Polymer Vesicles from Assembly of Mixture of Lipid-Modified Dextrans and Poly(r-glutamic acid)s and their Structural Characterization

• Main Authors: Yu-Wen Chen, 陳俞&;#24419;
• Other Authors: Sung-Chyr Lin
• Format: Others
• Language: zh-TW
• Published: 99
• Online Access: http://ndltd.ncl.edu.tw/handle/27637816813177853068

碩士 === 國立中興大學 === 化學工程學系所 === 98 === In this study, we have synthesized the biodegradable amphiphilic lipid-modified Dextrans (DO20) and Poly(r-glutamic acid)s (PGA-d15). These materials are obtained by partial transesterification of octadecanol and distearin. The chemical compositions of copolymers are precisely determined by 1H-NMR and FT-IR measurements. The dextran-based nanoparticles are attained by self-assembly of amphiphilic copolymers in DMSO/H2O co-solvents and then dialysis against water. Combining the results of 1H-NMR and dynamic light scattering (DLS) measurements, the size of nanoparticles can be controlled by adjusting the DMSO/H2O ratio during self-assembly of copolymers. According to the Rg/Rh ratios of the particles examined by static light scattering (SLS) are approximately 1.0, confirming strongly that the structure of assemblies is presented in vesicle-like form. Then, we mixed these two copolymers mentioned before with different ratios in the condition of fixed ratio of the DMSO/H2O. The vesicles are attained by self-assembly of mixed copolymers and then dialysis against pH 7.0 buffer solution. Here, we replace H2O with buffer solution, and it can make the glutamic acid moieties more stable. The results of DLS measurements show the size of mixed vesicles decrease with the rise of PGA-d15 in mixed ratio. For expanding the applications of polymer vesicles, we use small hydrophilic molecules and protein as probes to measure the efficiency of encapsulation. This study suggests these hydrophilic probes can be totally encapsulated inside the vesicles. As a result, these polymer vesicles have potential in drug delivery systems.