Cellular uptake of adamantyl conjugated peptide nucleic acids

Peptide nucleic acids (PNA) (15-mers) conjugated to adamantyl acetic acid a nd labeled with fluorescein have been prepared, and their (liposome mediate d) uptake in human cells in culture (HeLa, IMR-90 and MDA-MB-453) has been studied by confocal fluorescence microscopy. It is found that adamantyl-PNA s show greatly improved (endosomal) cellular uptake, but that this uptake i s dependent on the cell line. Cellular uptake of such lipophilic PNAs is fu rther mediated by cationic liposomes, and in some cases, the intracellular localization is diffuse cytoplasmic or nuclear, again cell-type dependent. The results show that this simple PNA modification can indeed greatly impro ve cellular uptake, but the effect appears strongly cell-type as well as PN A-sequence dependent.