Polydopamine-heparin complex reinforced antithrombotic and antimicrobial activities of heparinized hydrogels for biomedical applications

Large-scale fabrication of heparinized hydrogel could be accomplished by free-radical crosslinking polymerization (FRCP), whilst its bioactivity is often partially lost. Heparinized hydrogel based implantable medical devices, therefore, frequently encounter the compelling problems of thrombosis and microbial infection. In this study, a facile FRCP approach was proposed to fabricate heparinized hydrogels by preforming polydopamine-heparin (PDA-HEP) complex, which bypassed the steps of heparin functionalization and effectively preserved the function of heparin in the meantime. Compared with heparin mixed hydrogels, heparin in PDA-HEP complex composite hydrogels augmented the antimicrobial activity of PDA by enhancing the combined bactericidal action of cations and reactive oxygen species (ROS), while still maintaining its anticoagulant function. Since its integration of extremely low hemolysis rate, remarkable anticoagulation property and efficient bactericidal performance, we believe that this universal method of preparing heparinized hydrogels based on PDA-HEP complex will speed up the versatile application of hydrogel implants in clinical medicine.