Deshpande D, Blezinger P, Pillai R, Duguid J, Freimark B, Rolland A
GENEMEDICINE, INC., The Woodlands, Texas 77381-4248, USA.
Pharm Res. 1998 Sep;15(9):1340-7. doi: 10.1023/a:1011933117509.
Cationic lipids are capable of transferring foreign genes to the pulmonary epithelium in vivo. It is becoming increasingly clear that factors other than lipid molecular structure also influence efficiency of delivery using cationic lipid systems. This study is aimed at evaluating the effect of formulation variables such as cationic lipid structure, cationic lipid/DNA ratio, particle size, co-lipid content and plasmid topology on transgene expression in the lung.
The effect of varying the surface and colloidal properties of cationic lipid-based gene delivery systems was assessed by intratracheal instillation into rats. An expression plasmid encoding chloramphenicol acetyl transferase (CAT) was used to measure transgene expression.
Cationic lipid structure, cationic lipid/DNA ratio, particle size, co-lipid content and topology of the plasmid, were found to significantly affect transgene expression. Complexation with lipids was found to have a protective effect on DNA integrity in bronchoalveolar lavage fluid (BALF). DNA complexed with lipid showed enhanced persistence in rat lungs as measured by quantitative polymerase chain reaction.
Fluorescence microscopy analysis indicated that the instilled formulation reaches the lower airways and alveolar region. Data also suggests cationic lipid-mediated gene expression is primarily localized in the lung parenchyma and not infiltrating cells isolated from the BALF.
阳离子脂质能够在体内将外源基因转移至肺上皮细胞。越来越清楚的是，除脂质分子结构外，其他因素也会影响阳离子脂质系统的递送效率。本研究旨在评估诸如阳离子脂质结构、阳离子脂质/DNA比例、粒径、共脂质含量和质粒拓扑结构等制剂变量对肺中转基因表达的影响。
通过气管内滴注到大鼠体内来评估改变阳离子脂质基基因递送系统的表面和胶体性质的效果。使用编码氯霉素乙酰转移酶（CAT）的表达质粒来测量转基因表达。
发现阳离子脂质结构、阳离子脂质/DNA比例、粒径、共脂质含量和质粒拓扑结构显著影响转基因表达。发现与脂质复合对支气管肺泡灌洗液（BALF）中的DNA完整性具有保护作用。通过定量聚合酶链反应测量，与脂质复合的DNA在大鼠肺中的持久性增强。
荧光显微镜分析表明，滴注的制剂到达下呼吸道和肺泡区域。数据还表明阳离子脂质介导的基因表达主要定位于肺实质，而非从BALF中分离出的浸润细胞。
