Abstract: Biomedical molecule has received extensive application in surface modification coating. In this paper, polyethyleneimine (PEI)/heparin coating and chitosan/heparin coating on NiTi alloy substrates were prepared by layer-by-layer method, and differences of corrosion behavior and biocompatibility of the coatings were studied. Static contact angles and Fourier transform infrared (FT-IR) test were used to analysis the surface morphology and structure character of the materials, and atomic absorption spectrum was used to verify the corrosion behavior of the materials. Furthermore, hemolysis, dynamic clotting time and platelet binding test were utilized to investigate the biocompatibility of the materials. The results revealed that the blood compatibility of PEI/heparin coating is better than that of the chitosan/heparin coating as well as the substrate.

Key words: Biocompatibility, Corrosion behavior, Polyethyleneimine (PEI)/heparin, Chitosan/heparin, NiTi