Wittung P, Kajanus J, Edwards K, Haaima G, Nielsen P E, Nordén B, Malmström B G
Department of Physical Chemistry, Chalmers University of Technology, Göteborg, Sweden.
FEBS Lett. 1995 Nov 20;375(3):27-9.
Phospholipid vesicles (liposomes) as membrane models have been used to study the penetration properties of peptide nucleic acid (PNA), a new DNA analog in which the nucleobases are attached to a pseudo-peptide backbone. The liposomes were characterised by carboxyfluorescein efflux, light-scattering and cryogenic transmission electron microscopy. The liposome structure was found not to be affected by the incorporation of PNA or an oligonucleotide. Two 10-mer fluorescein-labelled PNAs were found to have low efflux rates (half-times of 5.5 and 11 days), comparable to that of a 10-mer oligonucleotide (half-time of 7 days). We conclude that passive diffusion of unmodified PNA over the lipid membrane is not likely to be an effective way of transport into biological cells.
磷脂囊泡（脂质体）作为膜模型已被用于研究肽核酸（PNA）的穿透特性，PNA是一种新的DNA类似物，其中核碱基连接到假肽主链上。脂质体通过羧基荧光素外排、光散射和低温透射电子显微镜进行表征。发现脂质体结构不受PNA或寡核苷酸掺入的影响。发现两种10聚体荧光素标记的PNA具有低外排率（半衰期分别为5.5天和11天），与10聚体寡核苷酸的外排率（半衰期为7天）相当。我们得出结论，未修饰的PNA在脂质膜上的被动扩散不太可能是转运到生物细胞中的有效方式。
