A novel low-cost spray coating machine for PLA solution on tubular metallic geometries

Abstract

Polymeric coating is one of the most used surface modification techniques on stents to reduce late stent thrombosis and restenosis. Coating process parameters must need to be rigorously controlled in biomedical applications. Spray coating is one of the most promising process used to recover commercial coronary stents, wherein uniform surfaces must be achieved. A novel low-cost spray coating machine was developed constructed using an airbrush with adjustable pressure (30 psi to 45 psi). Additionally, time and distance control systems were adapted for tubular samples, and a motor controlled their rotation. Polylactic acid (PLA) was deposited on 316L stainless steel tubes, using a spray coating technique for coronary stents purposes in order to achieve optimal film characteristics. Scanning electron microscopy was used to analyze the coating homogeneity. Other physical characteristics such as weight and surface roughness were measured to assess the feasibility of the proposed system.