Cell membranes as barriers for antisense constructions.

The results of studies on interaction of oligonucleotides and polynucleotides with cell membranes are reviewed. Oligonucleotides and polynucleotides bind to lipid membranes in the presence of divalent cations that may result in spontaneous encapsulation of nucleic acids and transfer of the formed vesicles to the other side of the membrane. Oligonucleotides can enter eukaryotic cells and interact with cellular RNA and DNA. On the surface of eukaryotic cells, there are proteins capable of binding to nucleic acids that may be involved in oligonucleotide uptake. Oligonucleotides bind to cellular CD4 receptors. Efficient delivery into cells can be achieved by conjugation of oligonucleotides to lipophilic groups or by encapsulation into membrane carriers.