Heparin coatings are widely applied on blood-contact materials to reduce the use of anticoagulants during blood treatment. However, the previous heparin coatings formed via covalent binding or electrostatic bonding commonly require complex surface premodification, and the blood coagulation pathway was significantly inhibited to potentially increase the bleeding risk. This contradicts the intended purpose and deviates from the anticoagulation mechanism of the heparin coatings. Herein, we present a facile and substrate-independent coating, achieved through the co-deposition of dopamine/chitosan followed by electrostatic interaction between heparin and the immobilized chitosan, which could be prepared within 1 hour. This coating prolonged the plasma re-calcification time (PRT) to over 60 minutes, effectively preventing surface-induced thrombosis. Favorable hemocompatibility was reflected in a hemolysis ratio of less than 2%, low levels of platelet adhesion and activation, and low levels of fibrinogen adhesion. We also systematically elucidate the anticoagulant mechanism of the coating, demonstrating why the coating can prevent thrombogenesis without the bleeding risk. Our work not only offers a promising and readily available heparin coating for blood-contact materials, but more importantly, the mechanism exploration supports the practical feasibility of heparin coating in various applications.
Xianqiang Zeng,Chen Liu,Xue Wang,Yan Cao,Peng He,Huiquan Li,Liguo Wang
The demand for underwater pressure sensitive adhesives (PSAs) is rapidly increasing in fields such as underwater engineering and biomedicine. However, the achievement of underwater adhesion of PSAs remains a challenge because of the hydration layer that hinders the interaction between the adhesive and the substrate. Herein, a new type of underwater PSA was synthesized by the copolymerization of hydrophobic unsaturated poly(1,2-butylene oxide) (UPBO) and hydrophilic itaconic acid monomers using solvent-free ultraviolet curing. The PSA has demonstrated substrate-independent underwater adhesion strengths ranging from 108 to 141 kPa on both hydrophilic (glass, wood, steel) and hydrophobic (PET, PMMA, PTFE) substrates. The underwater adhesion performance of PSA remains stable during 30 adhesion–detachment cycles and incubation in water for 20 days. Notably, PSA shows cytocompatibility, antimicrobial, and degradable properties and can be used for rapid hemostasis of skin wounds. Experimental characterizations confirm that the process of underwater adhesion is achieved by hydrophobic alkyl side chains of the PBO chain segments, which repel water at the adhesive–substrate interface. This study should provide both practical and facile design strategies for multifunctional underwater PSAs that can be used in a variety of applications.