Wittung P, Kajanus J, Edwards K, Nielsen P, Nordén B, Malmström B G
Department of Physical Chemistry, Chalmers University of Technology, Göteborg, Sweden.
FEBS Lett. 1995 May 22;365(1):27-9. doi: 10.1016/0014-5793(95)00409-3.
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 a 10-mer oligonucleotide (half-time of 7 days). We conclude that passive diffusion of unmodified PNA is not an effective way of transport into biological cells.
