In vitro studies of drug eluting biodegradable polymeric stent

Cardiovascular disease which is the prominent reason for morbidity and mortality,affects large number of world population. Coronary artery disease (CAD) constitutes largeclass of cardiovascular disease and mostly eventuate heart attack and death. Therefore,CAD treatment is extremely important. The studies proved that stent implantation is themost ideal and beneficial treatment way of CAD. There are different types of stents as baremetal stents, drug eluting coated metal stents, polymer stents and drug eluting polymericstents. The objective of this research was to investigate the in vitro convenience ofpaclitaxel eluting biodegradable polymeric stent for coronary arteries usingPLLA/PCL/PBS polymer blends. For this purpose, biocompatibility, cytotoxicity andthrombogenicity of the stent body material and the drug loaded stent coating were studied.In order to examine the biocompatibility of the stent body, MTS and Calcein AMassays were performed in this study. In addition to biocompatibility, thrombogenicityproperties of the stent body are substantially significant due to thrombosis and restenosisrisks. Therefore, thrombogenicity assay was applied to the polymers that were used forstent body. According to the results, the most appropriate polymer compositions due thebiocompatibility and thrombogenicity were determined and chosen as a potential polymerblend for stent construction.In the mean time, cytotoxicity of the drug loaded stent coating is very important dueto its apoptotic effect to the surrounding cells, smooth muscle cells and inflammatory cells.Therefore, the biocompatibility of the unloaded stent coating was searched first by MTSassay. Then, the apoptosis effect of the paclitaxel loaded stent coating was studied byCaspase-3 apoptosis assay. The results of the assays were considered and the potentialstent coating blend was decided. For future prospects, the design and the morphology ofthe stent will be decided and in vivo experiments will be performed.