Mussel-inspired post-heparinization of a stretchable hollow hydrogel tube and its potential application as an artificial blood vessel

We report the fabrication of a highly stretchable hydrogel tube and its postfunctionalization for potential application as an artificial blood vessel. Although stretchable hydrogels have been well studied in the last decade, functionalization of the hydrogel remains a grand challenge because of the deterioration of its mechanical strength induced by the newly incorporated functional monomers. Herein, we use a mussel-inspired coating method to bestow the highly stretchable hydrogel with super hemocompatibility; meanwhile, the mechanical properties of the hydrogel matrix were not obviously damaged. Briefly, dopamine grafted heparin was anchored to an alginate/polyacrylamide double-network hydrogel via the mussel-inspired coating. The prolonged activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT) demonstrated the enhanced anticoagulant activity of the heparin functionalized hydrogl tube. The clotting time, platelet adhesion, hemolysis ratio, and complement activation results of the hydrogel indicated that the heparinized hydrogel tube has excellent hemocompatibility and can be used as an artificial blood vessel. Compared to the unmodified hydrogel, the heparinized hydrogel also shows an improved cell adhesion affinity towards blood endothelial cells. More importantly, after the mussel-inspired coating, the mechanical strength of the highly stretchable hydrogel tube can be retained. Thus, the obtained highly hemocompatible hollow hydrogel tube can meet the needs of the dynamic functionality of stretchable blood vessels as well as other highly elastic soft tissues.