Chitosan-heparin polymers coated with

Wettability, surface free energy, surface charge and compliance have been studied. Heparinized surfaces have exhibited considerable compatibility with blood. Typically, heparin is surface bound using cationic materials including tridodecyl methylammonium chloride, benzalkonium chloride, octadecylamine and quaternary ammonium polymers. Since polyelectrolyte complexes of heparin and chitosan have been prepared and exhibit either thrombogenic or non thrombogenic properties chitosan can be coated onto artificial polymeric supports and then reacted with heparin or with heparin-like substances... 

Chitosan-heparin coated polymers display excellent thrombo-resistance properties. The lifetime of the thromboresistance can be extended by covalently binding the heparin to chitosan with the aid of sodium cyanoborohydride. This surface treatment is useful for biomedical applications requiring blood compatibility for periods as long as four days. 

---