Citation:
Cardiovasc Radiat Med. 2003 Jul-Sep;4(3):152-9
Abstract:
HYPOTHESIS: The antisense phosphorodiamidate morpholino oligomer (PMO), AVI-4126, has been effective in reducing neointimal formation in animal models following delivery by pluronic gels, local delivery catheters and coated stents. Greater flexibility of repeated-dosage regimens and reduced procedure complexity may be provided by systemic injection of AVI-4126 bound to perfluorobutane gas microbubble carriers. The purpose of this study was to investigate the effects of perfluorocarbon gas microbubble carrier (PGMC)-based systemic delivery of AVI-4126 on expression of the c-myc in vascular tissue and restenosis after stent implantation. METHODS: Seven pigs underwent stent implantation (3 stents/animal). Five pigs received IV injection of PGMC and 2 mg of AVI-4126 (AVI BioPharma). Two served as control. Four hours postprocedure, 3 pigs were sacrificed and stented segments analyzed by high-performance liquid chromatography (HPLC) and Western blot. In chronic experiments, 4 pigs (12 stent sites) were sacrificed at 28 days. RESULTS: HPLC analysis of plasma samples of treated animals showed minimal presence of AVI-4126. HPLC of the treated arteries demonstrated easily detected concentrations of AVI-4126. Western blot analysis of the stented vessels demonstrated modest inhibition of c-myc. Morphometry showed that the neointimal area was significantly reduced in the AVI-4126/PGMC group compared with control (2.63+/-1.99 vs. 4.77+/-.1.71 mm(2), respectively, P<.05). CONCLUSION: In the porcine coronary stent model, systemic targeted delivery of AVI-4126 using PGMC carrier significantly inhibited neointimal formation.