Responses of platelets and endothelial cells to heparin/fibronectin complex on titanium: In situ investigation by quartz crystal microbalance with dissipation and immunochemistry

Platelet adhesion and endothelialization rates are frequently used to assess the biocompatibility of biomaterials, which are crucial steps for the development of blood-contacting implanted devices. Co-immobilization of heparin and fibronectin (Hep/Fn) on titanium (Ti) surface has been proven to inhibit platelet adhesion and enhance endothelialization in our previous study, however, the interaction mechanisms of platelet and endothelial cell (EC) with biomolecules immobilized surface at the early stage are still not clear. In this study, the adhesion behavior of EC and platelet on biomolecules immobilized surface was evaluated using quartz crystal microbalance with dissipation (QCM-D) in real time and immunofluorescence/optical measurement. And the possible underlying mechanism was probed using immunochemistry. The results showed that EC underwent attachment and spreading process on Hep/Fn (pH 4) immobilized surface similar to that on bare Ti surface, while platelet displayed much larger activation on bare Ti surface than that on Hep/Fn (pH 4) immobilized surface. However, the adhesion behaviors of platelets and EC reflected in Df plots were different. The study brings forth the detailed interaction between heparin and fibronectin and the interaction of EC and platelet with the biomolecules coated surface, which will be helpful for better understanding the interaction mechanism of cell–biomaterials interface and may potentially be useful for the development of new generation of cardiovascular biomaterials.