The
thrombosis of the extracorporeal circuits leads to serious complications, which affect the life safety of the patients significantly. However, intravenous
anticoagulants such as
heparin may induce
bleeding,
hypersensitivity, and other adverse reactions. In this study, the mussel-inspired composite coating consisting of
polydopamine (
PDAM),
lysine, and modified
heparin was constructed on the commonly used medical poly(
vinyl chloride) (
PVC) tubes to reduce
thrombosis by combining the immobilization of
anticoagulants and the construction of bioinert surface strategies. First, the
PDAM/
lysine coating rich in
amine groups was constructed in a mixed
solution of
dopamine and
lysine through the co-deposition reaction. Then, the modified
heparin was covalently immobilized on the
PDAM/
lysine coating to obtain composite coating. Finally, the graft density and stability of
heparin and
anticoagulant properties of the composite coating were tested. The results showed that the composite coating could inhibit the adhesion and activation of platelets significantly and prolong the activated partial thromboplastin time (APTT) remarkably for over 25 s. The composite coating also had excellent hemocompatibility, and the
hemolysis ratio was less than 0.5%. Particularly, the
anticoagulant coating performed well in the in vitro blood circulation test. The composite coating constructed in this work show great potential in the
anticoagulant treatment for medical devices.