Construction of drug-eluting polymeric biodegradable stent

Coronary Artery Disease (CAD) is the most widespread disorder of heart disease for adults. With the progressive aging of the population, cardiovascular disease has become more definitely the main cause of death and coronary heart disease the major form of fatal cardiac disease. Without treatment of the disorder of coronary arteries can lead to serious problems and even death.Treatment of coronary artery disease is aimed at controlling symptoms and slowing or stopping the progression of disease. The aim of this project is to demonstrate stent implantation, the most important and beneficial way of CAD treatment.The ultimate aim of this study was to construct drug eluting biodegradable polymeric stent for the treatment of coronary artery disease. The intended design of stent consists of two layers (inner and outer), where an appropriate polymer matrix embedding a drug, namely paclitaxel releases the drug over a desired period of time, such as one month. For the inner layer, biodegradable polymer blends were prepared via melt blending to obtain required mechanical properties with degradation in about 12 months.The release profiles of the drug (paclitaxel) from PLLA-PCL blends were determined by using HPLC and these blends were found to release the drug depending on the film thickness and blend composition.The degradation studies were carried out by pH and weight measurements and degradation times were shown to depend on polymer blend composition. The crystallinity of polymer blends were determined by using Differential Scanning Calorimetry (DSC) and the DSC analysis of the PLLA-PCL blend solution cast films indicated that these blends are all phase separated. In the mean time, Scanning Electron Microscopy (SEM) was used to investigate the morphology of polymer blends where again the pahse separation was evident. As complementary experiments, in vitro studies of polymer blends were studied to examine the biocompatibility and all blends were found to be biocompatible, thus suitable for the desired application.