Inserm U1022- CNRS UMR8151, Paristech, Unité de Pharmacologie Chimique et Génétique et d'Imagerie, Université Paris Descartes, Paris, France.
J Gene Med. 2010 Jun;12(6):491-500. doi: 10.1002/jgm.1460.
Nonviral gene therapy still suffers from low efficiency. Methods that would lead to higher gene expression level of longer duration would be a major advance in this field. Lipidic vectors and physical methods have been investigated separately, and both induced gene expression improvement.
We sought to combine both chemical and physical methods. Cationic or anionic lipids can potentially destabilize the cell membrane and could consequently enhance gene delivery by a physical method such as electrotransfer. A plasmid model encoding luciferase was used, either free or associated with differently-charged lipoplexes before electrotransfer.
Electrotransfer alone strongly enhanced gene expression after intramuscular and intradermal injection of naked DNA. On the other hand, cationic and anionic lipoplex formulations decreased gene expression after electrotransfer, whereas poorly-charged thiourea-based complexes, brought no benefit. Pre-injection of the lipids, followed by administration of naked DNA, did not modified gene expression induced by electroporation in the skin.
The results obtained in the present study suggest that packing of DNA plasmid in lipoplexes strongly decreases the efficiency of gene electrotransfer, independently of the lipoplex charge. Non-aggregating complexes, such as poorly-charged thiourea-based complexes, should be preferred to increase DNA release.
非病毒基因治疗仍然效率低下。如果能找到提高基因表达水平和延长表达时间的方法，将是该领域的重大进展。脂质体载体和物理方法已分别进行了研究，两者都能提高基因表达。
我们试图将化学和物理方法结合起来。阳离子或阴离子脂质可能会破坏细胞膜，从而通过电转移等物理方法增强基因传递。我们使用了一种编码荧光素酶的质粒模型，在电转移之前，它可以自由存在，也可以与带不同电荷的脂质体复合物结合。
电转移单独使用可显著增强肌肉内和皮内注射裸 DNA 后的基因表达。另一方面，阳离子和阴离子脂质体配方在电转移后降低了基因表达，而带较少电荷的硫脲基复合物则没有带来益处。在注射脂质体之前，先给予裸 DNA，并不会改变电穿孔对皮肤诱导的基因表达。
本研究结果表明，脂质体复合物包封 DNA 质粒会大大降低基因电转移的效率，而与脂质体的电荷无关。应选择非聚集复合物，如带较少电荷的硫脲基复合物，以增加 DNA 的释放。
