Abstract:
The quality of drug controlled-releasing coating (including three layers, the base coating, the drug matrix coating, the top coating) on the 316L stainless steel was influenced by many determinants. Among them, the polymer was the primarily important factor. In this paper, the taxol was used as model drug, polyethylene-vinyl alcohol(EVAL), polyethylene-vinyl acetate(EVA), polylactic co-glycolid acid (PLGA), which were widely applied as biomedical materials, were applied as coating polymers. The comprehensive characteristics of EVAL, EVA, PLGA coatings on stainless steel stents were investigated in details, including the bonding strength of the coatings, the drug solubility, drug diffusion coefficient, stress and tension of the coatings, surface free energy and surface hydrophilicity. The results indicate that EVA is an ideal material as base and drug matrix coating, whereas PLGA is a suitable material for the top coating.