Surface modification of 316L stainless steel by using pulsed laser

Abstract

Coronary stent is a mechanical medical devices design to open the arteries that have been affected by coronary artery disease (CAD). Blood vessel obstruction is the result of atherosclerosis by the buildup of smooth muscle cells, lipid containing vacuoles, calcification and additional cellular debris. Stent devices are introduced in clinical uses not to remove the obstruction but to create larger lumen within the lesion to provide smooth blood circulation. The introduction of stent to act as scaffold device to maintain the luminal integrity of the diseased coronary artery was able to return a patient’s normal lifestyle shortly after treatment. Despite all the advantages, in-stent restenosis caused by vascular smooth muscle cell (VSMC) proliferation and thrombosis caused by platelet aggregation remain the major complications of coronary stenting, which hamper the longterm success of the treatment. Pulsed laser surface modification approach holds great promise in overcoming the current limitations of stent therapy. The material must be biocompatible with the associated cells. To enhance the biocompatibility, researches have been done such as drug coating, changing of material composition and surface modification of the stent. Coating and changing material both had expensive manufacturing cost, it is not economical to undeveloped country, while surface modification is the cheapest in manufacturing cost which can also improve the stent biocompatibility. A total of 6 specimen with different texture design are produce and after running testing and analysis, 2 texture is selected in the end. Texture C-01 and S-01 are selected as the most promising texture. Defect such as recast layer, micro-crack also been reported relate to changes in input parameters.