Currently available cardiovascular implants, such as heart valves and stents, exhibit suboptimal
biocompatibility because of the incomplete endothelialization and sequential thrombosis formation
especially after a long-term implantation. To improve the blood compatibility and endothelialization
simultaneously and ensure the long-term effect of the cardiovascular implants, a technique of combining
electrostatic interaction and coimmobilization was developed to form heparin and fibronectin (Hep/Fn)
films on aminosilanized titanium (Ti) surfaces. The Hep/Fn coimmobilized films were stable after
immersion in PBS for five days, probed by wettability studies and by the release kinetics of heparin and
fibronectin. Blood compatibility tests showed that the coimmobilized Hep/Fn films displayed lower
hemolysis rate, prolonged blood coagulation time, higher AT III binding density, less platelets activation
and aggregation, and less fibrinogen conformational change compared with Ti surface. Endothelial cells
(ECs) seeding and fibronectin bioactivity results showed more attached and proliferated ECs and exposed
cell-binding sites on the Hep/Fn immobilized samples than that on Ti surfaces. Thus, the Hep/Fn
coimmobilized films kept excellent bioactivity even after immersion in PBS for five days. Systemic
evaluation suggests that the coimmobilization of Hep/Fn complex improves the blood compatibility and
promotes the endothelialization simultaneously. We envisage that this method will provide a potential
and effective selection for biomaterials surface modification of cardiovascular implants.


Guicai Li,Ping Yang,Wei Qin,Manfred F.Maitz,Shuo Zhou,Nan Huang.