In vitro membrane penetration of modified peptide nucleic acid (PNA)
Artikel i vetenskaplig tidskrift, 1999

Efficient cellular uptake is crucial for the success of any drug directed towards targets inside cells. Peptide nucleic acid (PNA), a DNA analog with a promising potential as a gene-directed drug, has been shown to display slow membrane penetration in cell cultures. We here used liposomes as an in vitro model of cell membranes to investigate the effect on penetration of a PNA molecule colvalently modified with a lipophilic group, an adamantyl moiety. The adamantyl attachment was found to increase the membrane-penetration rate of PNA three-fold, as compared to corresponding unmodified PNA. From the penetration behaviour of a number of small and large molecules we could conclude that passive diffusion is the mechanism for liposome-membrane passage. Flow linear dichroism (LD) of the modified PNA in presence of rod-shaped micelles, together with octanol-water distribution experiments. showed that the adamantyl-modified PNA is amphiphilic; the driving force behind the observed increased membrane-penetration rate appears to be an accumulation of the PNA in the lipid double layer.


Malin Ardhammar

Institutionen för fysikalisk kemi

Bengt Nordén

Institutionen för fysikalisk kemi

P.E. Nielsen

Bo Malmström

P. Wittung-Stafshede

Journal of Biomolecular Structure and Dynamics

0739-1102 (ISSN)

Vol. 17 33-40


Nanovetenskap och nanoteknik


Livsvetenskaper och teknik



Fysikalisk kemi


Grundläggande vetenskaper