Pharmacokinetics of antisense oligodeoxyribonucleotides (cyclin B1 and CDC 2 kinase) in the vessel wall in vivo: enhanced therapeutic utility for restenosis by HVJ-liposome delivery.

Using a highly efficient viral HVJ (hemagglutinating virus of Japan) liposome-mediated transfer method, we examined the cellular fate of antisense oligodeoxyribonucleotides (oligos) in the vessel wall in vivo. Direct transfer of unmodified FITC (fluorescein isothiocyanate)-labeled oligos into injured rat carotid arteries showed, localized in the medial layer, fluorescence that disappeared within 1 day. In contrast, transfection of unmodified FITC-oligos by the HVJ-liposome method showed, concentrated in the medial layer, high levels of fluorescence that were sustained for at least 1 week. Moreover, we demonstrated nuclear localization and accumulation of fluorescence in the vessel wall using this method. To examine the therapeutic utility of this method, we transferred antisense phosphorothioate oligos against cyclin B1- and CDC2 kinase-encoding genes into balloon-injured rat carotid artery as a potential therapy for experimental restenosis. Two weeks after transfection, antisense oligo treatment directed against either CDC2 kinase or cyclin B1 resulted in a partial, but significant, inhibition in neointima formation. In contrast, transfection of either sense or scrambled control oligos had no effect. Interestingly, co-transfection of antisense oligos against CDC2 kinase and cyclin B resulted in further inhibition of neointima formation, as compared to blockade of either gene target alone. These results demonstrate that: (i) the HVJ-liposome method enhances the half life and nuclear localization of antisense oligos in the vessel wall in vivo; and (ii) HVJ-mediated administration of antisense CDC2 kinase and cyclin B1 oligos produces a sustained inhibition of neointima formation after balloon angioplasty.