Carbohydrate polymer grafting on stainless steel surface and its biocompatibility study

Surface science plays a critical role in biomaterials development as most biological reactions occur at their surfaces. The suitable choice of coating material, the surface structure and its biocompatibility are essential for fabricating a biomaterial. Herein, we have developed a biocompatible surface modification technology composed of surface electropolishing and carbohydrate polymer grafting, which can be applied to stainless steel, the most widely used stent. The surface of the stainless steel was sequentially modified by acid-treatment, silanization, and covalent attachment of chitosan and dextran. The extensive surface analysis confirmed that the surface was changed from hydrophobic to hydrophilic and from rough to smooth. The biological experiments revealed that the surface-modified stainless steel not only inhibited non-specific fibrinogen adsorption but also repelled most of proteins from human blood, when compared to bare stainless steel. It was demonstrated that our simple approach for surface modification could efficiently improve the biocompatibility of a stainless steel-based medical device.