Antisense oligonucleotides ASOs

Parenteral administration has been the preferred route because it allows complete systemic availability. Non-parenteral administration of antisense oligonucleotides is only made possible with the aid of novel formulations intended to overcome barriers to absorption (see Chapter 10). Similar to first-generation anti-sense oligonucleotides (ASOs), the pharmacokinetics of2 -MOE partially modified ASOs are characterized by ... 

We and others have demonstrated that Raf-1 protein serine/threonine kinase is a druggable signaling molecule in cancer therapy (1,13,17,21-25). Our laboratory has developed a novel cationic liposomal formulation for systemic delivery of intact raf ASO (LErafAON) to normal and tumor tissues in mice (13,17). The liposome-entrapped raf antisense oligonucleotide (LErafAON) is also the first liposomal ASO drug tested in humans (26,27). Systemically delivered cationic liposomal nanoparticles containing rafsiRNA (LErafsiRNA) also inhibit Raf-1 protein expression in tumor and most normal tissues in human prostate tumor (PC-3)-bearing athymic mice (Fig. 1 and Color Plate 1, see Color Plate Section). 

Boado et al. [28] devised delivery systems based on conjugates of streptavidin and the 0X26 monoclonal antibody directed to the transferrin receptor as a carrier for the transport of ASO. These delivery systems were found to transport peptide nucleic acid antisense molecules, but not ASO, across the BBB. These authors attributed this difference to preferential binding of phosphorothioate oligonucleotide to plasma protein instead of the antibody complex, which reduced their transport. 

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