Résumés disponibles (85) :

HERTAULT Adrien (INSERM U1008 - Stephan HAULON)
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@mail :  adrien.hertault@chru-lille.      tél. :  0320445962

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Titre de la communication :
Evaluation of a Pro-Healing Polydopamine-coated Stent on In-Stent Restenosis using a rat model
Auteurs (et leurs adresses) de la communication :
Adrien Hertault, Blandine Maurel, Feng Chai, Mickaël Maton, Florent Briffa, Nicolas Bricout, Jonathan Sobocinski, Stephan Haulon, Nicolas Blanchemain, INSERM U1008, Research Group on Biomaterials, University of Lille, Fran
Résumé de la communication :
INTRODUCTION: In-stent restenosis (ISR) is induced by an uncontrolled smooth muscular cells (SMC) proliferation after stent implantation. It is associated with recurrence of symptoms and additional health costs. Drug-eluting stents have demonstrated efficiency on ISR, but induce a high risk of late acute thrombosis due to a delayed struts reendothelialization1. Polydopamine (PDA), a biocompatible polymer inspired from mussels byssus, has been reported to promote endothelial cells (EC) and SMC proliferation in-vitro2,3, thus suggesting a potential pro-healing effect on the vascular wall. This study aimed to evaluate the impact of a pro-healing PDA-coated stent on in-stent restenosis (ISR) and on the quality of the struts re-endothelialization in-vivo using a rat model.
EXPERIMENTAL METHODS: Chemical oxidation of Cobalt-Chromium (CoCr) plates was achieved using a “piranha” solution mixture. PDA coating was performed by dip coating in a 2mg/mL dopamine solution, followed by rinsing in deionized water and thermal treatment at 150°C4 for one hour. Surface morphologies were assessed on PDA-coated CoCr plates by scanning electron microscopy (SEM). Ten Wistar rats received the implantation of 2.5mm CoCr coronary stent in aortic position (5 bare metal stents (BMS), 5 PDA stents, prepared according to the same protocol) and then sacrificed on the 28th day. Eight rats were used to estimate ISR in optic microscopy with quantification of the neointima/media (n/m) ratio after eosin/hematoxillin coloration5. Quality of the struts reendothelialization was analyzed in the two remaining rats with transmission electron microscopy (TEM).
RESULTS AND DISCUSSION: Visual aspect of PDA-coating appears smooth and homogeneous, however SEM analyses with a scratch test revealed a rough surface of around 50 nm in depth.
On the ten rats, one died of bleeding complications after stent implantation in the BMS group. PDA stents demonstrated a significant reduction in ISR compared to bare metal stents (ratio n/m = 0.48 (+/- 0.26) versus 0.83 (+/- 0.42), p<0.001). TEM analyses confirmed the presence of neointima surrounding the struts in each group, and revealed a thinner neointima layer in the PDA-stent group compared to BMS (Figure 2), with similar ultrastructures of the cells facing the arterial lumen.

CONCLUSION: The pro-healing effect expected of PDA-coating on the arterial wall seems to be confirmed in this in-vivo model. This biocompatible polymer could intrinsically limit in-stent restenosis. Additionally, it also offers the possibility to immobilize many relevant drugs on its surface through amine functions providing potential synergistic effects.

HERTAULT Adrien (INSERM U1008 - Stephan HAULON)