Etienne Schacht

772–6 Anglopeptin Loaded Stents Inhibit the Neointimal Reaction Induced by Polymer Coated Stents Implanted In Porcine Coronary Arteries

Poly(organo)phosphazene polymer (PP) coated on metallic coronary stents induce a severe histiolymphocytic and fibromuscular reaction leading to major coronary stenosis 6 weeks after stent implantation in a porcine coronary model. PP coated stents were loaded with angiopeptin (AP) (5 wt %) and stent stenosis was evaluated using quantitative coronary analysis and histopathology. A total of 14 pigs (7 received an AP loaded stent, 7 a non AP loaded stent (NAP) were studied. Minimal luminal stent diameter (MLSD) was measured using a semi-automated edge detection algorithm (Polytron ® 1000 Siemens) Pre stent implantation MLSD;APL:2.5xa0±xa00.2xa0mm; NAPL 2.6xa0±xa00.4xa0mm(NS). Post stent implantation MLSD:APL:3.0xa0±xa00.4xa0mm; NAPL 3.4xa0±xa00.3xa0mm (NS). After 6 weeks MLSD was significantly higher in the APL group compared with the NAPL group 2.2xa0±xa00.6xa0mm vs 1.7xa0±xa01.0xa0mm (pxa0lxa00.01). Histopathology demonstrated a severe histiolymphocytic and fibromuscular reaction in both groups but vessel narrowing was significantly more important in the NAPL group compared with the APL group (87.6xa0±xa011.5% vs 63.4xa0±xa018.2%; pxa0lxa00.01). These results suggest that local AP delivery using an AP loaded polymer coated stent is able to inhibit the foreign body reaction induced by poly(organo)phosphazene stent coatings.

Synthetic polyamines as vector for gene delivery

We report the synthesis and physicochemical evaluation of a series of cationic polymethacrylates as vectors for gene delivery. Two different types of polymer have been synthesized: The first is a series of polymers containing tertiary amine, pyridine, imidazole and acid groups; the second is a series of polyamines containing poly(ethylene oxide) (PEO) blocks or grafts. The ability of the different polymers to condense DNA has been studied by agarose gel electrophoresis; all polymers are able to condense DNA, their ability to do so being dependent on their chemical composition and molecular weight. The particle size of the different polymer-DNA complexes formed has been measured by dynamic light scattering: complexes have a particle size of around 50nm. A clear effect of the chemical composition of the polymers on the zeta potential of their complexes with DNA is evident.