Cellular delivery of peptide nucleic acid by cell-penetrating peptides.

Peptide nucleic acid (PNA) is a promising tool in biomedical research. PNA oligomers can be synthesized according to peptide synthesis protocols, but they hybridize to complementary RNA and DNA strands like oligonucleotides. The main hindrance to the use of PNA oligomers has been their poor uptake by cells. Fortunately, this limitation can be overcome by the application of peptide vectors. Different strategies are used to conjugate peptide vectors and PNA oligomers. In this chapter we discuss different types of delivery vectors (receptor ligands and cell-penetrating peptides) and strategies for the design and synthesis of PNA-vector conjugates. A protocol for the delivery of antisense PNA oligomer-cell-penetrating peptide conjugates is also described.