Maitani Yoshie, Igarashi Saki, Sato Mamiko, Hattori Yoshiyuki
Institute of Medicinal Chemistry, Hoshi University, Ebara 2-4-41, Tokyo 142-8501, Japan.
Int J Pharm. 2007 Sep 5;342(1-2):33-9. doi: 10.1016/j.ijpharm.2007.04.035. Epub 2007 May 10.
Cationic liposomes composed of 3beta-[N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and dioleoylphosphatidylethanolamine (DOPE) (DC-Chol/DOPE liposome, molar ratio, 1:1 or 3:2) prepared by the dry-film method have been often used as non-viral gene delivery vectors. The formulation and preparation of DC-Chol/DOPE liposomes, as well as the formation of their lipoplexes were investigated in an attempt to improve transfection efficiency in vitro. A more efficient transfection in medium with serum was achieved using DC-Chol/DOPE liposomes (molar ratio, 1:2) than those (3:2), and preparation method by a modified ethanol injection than the dry-film. The most efficient DC-Chol/DOPE liposome for gene transfer was molar ratio (1:2) and prepared by a modified ethanol injection method. The enhanced transfection might be related to an increase in the release of DNA in the cytoplasm by the large lipoplex during incubation in optiMEM, not to an increased cellular association with the lipoplex. The use of a modified ethanol injection method might enhance the role of DOPE that is aid in destabilization of the plasma membrane and/or endosome. These findings suggested that cationic liposomes rich in DOPE prepared by a modified ethanol injection method will help to improve the efficacy of liposome vector systems for gene delivery.
由干膜法制备的、由3β-[N-(N',N'-二甲基氨基乙烷)-甲酰胺基]胆固醇（DC-Chol）和二油酰磷脂酰乙醇胺（DOPE）组成的阳离子脂质体（DC-Chol/DOPE脂质体，摩尔比为1:1或3:2）常被用作非病毒基因递送载体。为提高体外转染效率，对DC-Chol/DOPE脂质体的配方、制备及其脂质复合物的形成进行了研究。使用DC-Chol/DOPE脂质体（摩尔比为1:2）比使用（3:2）的脂质体在含血清的培养基中能实现更高效的转染，且改良乙醇注入法比干膜法制备的转染效率更高。用于基因转移的最有效的DC-Chol/DOPE脂质体是摩尔比为（1:2）且通过改良乙醇注入法制备的。转染增强可能与在optiMEM中孵育期间大的脂质复合物使DNA在细胞质中的释放增加有关，而不是与脂质复合物和细胞的结合增加有关。使用改良乙醇注入法可能增强了DOPE在使质膜和/或内体不稳定方面的作用。这些发现表明，通过改良乙醇注入法制备的富含DOPE的阳离子脂质体将有助于提高脂质体载体系统用于基因递送的功效。
