本研究主要是利用陽離子型高分子-聚乙烯亞胺 (polyethylenimine，PEI) 與不同分子量的生物可分解性高分子-聚乳酸-乙醇酸(poly(lactide-co-glycolide)，PLGA)，合成具有帶正電性胺基的兩性高分子。利用紅外線光譜儀 (FT-IR) 和核磁共振光譜儀 (NMR) 分析確認其化學結構，並將合成產物利用透析的方式在水溶液中，由分子間作用力自組裝 (self-assembly) 形成核-殼 (core-shell)構造的奈米微胞。以動態光散射粒徑分析儀 (DLS) 及表面電位分析儀觀察粒徑大小及表面電位，並藉由膠體電泳分析奈米微胞與 DNA 的結合能力。另外，以 MTT assay 進行細胞毒性測試，最後測試複合體的細胞轉染效率。我們發現，形成的奈米微胞能達到良好的 DNA 結合效果、低細胞毒性與高轉染效率，可作為一個成功的基因傳遞載體。 The aim of this study is the synthesis of a biodegradable polymeric micelles obtained through the reaction between polyethylenimine (PEI) and different molecular weight poly(lactide-co-glycolide)(PLGA). Nanoparticles were prepared from polymer by dialysis putting the synthetic polymer in aqueous solution to form a core-shell structured polymeric micelles via intermolecular self-assembly effect. The chemical structures of polymeric micelles were indentified by FT-IR and NMR . The physical and chemical properties of micelles and DNA complex, were discussed such as observing particle morphology, dimension, and surface potential by dynamic light scattering (DLS) and zeta-potential analyzer. To analysis the binding capacity of polymeric micelles and DNA using gel electrophoresis. In addition , the cytotoxicity was evaluated with MTT assay. We found that the formed polymeric micelles can combine DNA into achieve a nano-complexes particles with low cytotoxicity and high transfectional efficiency. In this article, polymeric micelles seemed to be a novel cationic polymer for gene delivery and an interesting candidate for further study.
