Functionalization of polyurethane surfaces for further attachment of bioactive molecules

The challenge for cardiovascular tissue engineers is to design hemocompatible biomaterials that promote neo-tissue formation. Cardiovascular implants are prone to occlusion caused by surface thrombogenicity. In native tissue non-thrombogenic surface is provided by the endothelium. Endothelialization of implantable cardiovascular devices is thereby among the techniques of functionalizing biomaterials. Surfaces covered with peptides have been shown to enhance endothelial cells adhesion and proliferation. For the purpose of further cell-specifi c peptides immobilization, a three-step method for incorporating carboxyl groups onto a polyurethane surface was developed. In the fi rst step silanol groups were incorporated into the polyurethane surface. Successful reaction was proven by FTIR analysis. Subsequently, incorporation of surface amine groups was proceeded. In the last step amine groups were acylated using glutaric anhydride to create carboxylates. To determine the presence of surface functional groups, colorimetric method was applied. Measurement of water contact angle revealed signifi cant increase in surface hydrophilicity.