Thrombin-responsive Hydrogel Coating with Sustainable Resistance to Nonspecific Protein Adsorption

Constructing the surface coating with both biological inertness and responsive antithrombotic activity is an ideal way to solve the problem of foreign-material induced thrombosis in the applications of blood-contact medical devices. In this work, a thrombin-responsive hydrogel coating is designed and prepared based on onestep photocuring. The coating can sustainably resist non-specific protein adsorption and specifically inhibit thrombus formation in a thrombosis responsible way. Poly(ethylene glycol diacrylate) (PEGDA) and a thrombin-cleavable peptide (Pep) were used in the photo-initiated polymerization system. PEGDA worked as the main skeleton component as well as crosslinker, and the peptide mainly as the thrombin-cleavable crosslinker. The fibrinolytic molecule, tissue plasminogen activator (t-PA), was loaded during the hydrogel forming. The results showed that the coating could keep resistance to non-specific protein adsorption in normal blood environment and specifically trigger the release of t-PA in the presence of thrombin so that the nascent clot can be lysed. Moreover, the hydrogel coating could maintain the basic skeleton and thus the resistance to protein adsorption could be kept even after degradation by thrombin. In general, this research provides new ideas for optimizing the antithrombotic properties of blood contacting medical devices.