서강대학교

초록/요약

In this study, biodegradable polymer was used as a drug carrier to generate stents loaded with different drug. These stents were prepared by ultrasonic atomizing spray coating. Ultrasonic atomizing spray nozzle uses a low-pressure air/gas to produce a soft, highly focused beam of small spray drops. An isolated hypotube delivers liquid to the nozzle’s atomizing surface while air/gas, delivered through the nozzle orifice at a fixed low pressure, shapes the atomized drops into a very precise, targeted spray. The stent was moved both in the traverse direction and rotated during the spraying process. The morphology of the drug-eluting stents was examined by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). This indicated that the coating was very smooth and uniform. The coating was found to have the ability to withstand the compressive and tensile strains imparted without cracking during the stent inflation process. In vitro release profile of drug was measured by high performance liquid chromatography (HPLC). The release behavior of drug from the stent surface had a two phase release profile with a burst release period of about 2 days, followed by a sustained and slow release phase. The mass loss behavior of biodegradable polymer appeared linear throughout most of the degradation period. Platelet adhesion and fibrinogen adsorption tests showed that heparin loaded stents have high blood-compatibility use as vascular drug-eluting stent. Using released sirolimus coated stent evaluated anti-proliferation effect of rat vascular smooth muscle cells (RVSMC). In pre-clinical assessment, neointimal formation was found to be significantly decreased for sirolimus-eluting stents as compared to bare-metal stents (BMS) at 28 days. Assessment of vascular healing revealed an absence of increased inflammation in drug-eluting stents. Inflammation is commonly observed in drug-eluting stents (DES) with non-biodegradable polymeric coatings. Taking these results into account, the proposed drug-eluting stents may be good candidates to resolve in-stent restenosis and initial thrombus formation.