DNA與siRNA已廣泛的應用在基因治療的基礎研究，以各種病毒性與非病毒性載體來加強轉染及基因的表現。雖然病毒性載體在體內與體外有較佳的基因轉染效率，但一些像是免疫性、毒性及DNA大小限制的問題，使得有低免疫性、低毒性及容易操作等優點的非病毒性載體，讓釵h研究者成為另一種的選擇。Polyethylenimine (PEI)在非病毒性載體選擇中，有較佳的基因傳遞效率，但有相對較高的細胞毒性是其缺點，本研究主要是以PEI 25k
與poly(lactide-co-glycolide)(PLGA)為基質，使用PVA當安定劑，以Emulsion - diffusion - evaporation的技術製成均勻且帶正電性的奈米顆粒，藉由原子力顯微鏡(AFM)、動態光散射粒徑分析儀(DLS)及表面電位分析儀分析不同配方組成的正電性奈米顆粒的粒徑形態與大小及表面之電位，再以膠體電泳分析以瞭解正電性奈米顆粒對DNA的包覆能力，藉由不同配方組成及與DNA複合比例，研究正電性奈米顆粒對降低細胞毒性及提昇細胞之轉染效率的趨勢。 Gene therapies for DNA and siRNA have been widely investigated in fundamental research. Various viral and non-viral carriers have used to enhance transfection and gene expression efficiencies. Although viral carriers display rather good gene trnasfection efficiency, both in vitro and in vivo, but some problem as immunogenicity, toxicity, limitations in the size of inserted DNA. Therefore, low immunogenicity, low toxicity, and good handling properties of non-viral carriers to become another kind of choice, let many researchers put into the research. Polyethylenimine (PEI) at non-viral gene delivery system has good gene transfection efficiency, but the relatively high cytotoxicity is shortcoming. The aim of this study is the preparation of PEI 25k and poly (lactide-co-glycolide) (PLGA) nanoparticles formed by an emulsion method (emulsion-diffusion-evaporation) using PVA as a stabilizer. The particles size was characterized by atomic force microscopy (AFM) and dynamic light scattering (DLS). Zeta potential and gel electrophoresis studies were also performed to understand surface properties of carrier and their ability to bind negatively charged DNA. Then appropriate prescription composition with DNA complex ratio, to understand reduce to toxicity efficiency and enhance transfection efficiency of the cell.