Ex vivo evaluation of blood coagulation on endothelial glycocalyx-inspired surfaces using thromboelastography

Abstract

Present blood-contacting materials have not yet demonstrated to be effective in reducing blood coagulation without causing additional side effects clinically. We have developed an endothelial glycocalyx-inspired biomimetic surface that combines nanotopography, heparin presentation, and nitric oxide (NO)-releasing features. The resulting modified surfaces have already shown promise in reducing unfavorable blood-material interactions using platelet-rich plasma. In this study, the efficacy of modified surfaces for reducing coagulation of human whole blood was measured. In addition, the effects of leached polysaccharides and chemical modification of the modified surfaces were evaluated. Leached polysaccharides in the incubation solution were detected by a refractive index method to determine the potential influences of these modified surfaces on the blood coagulation observation. Chemical modifications by the nitrosation process on the polysaccharides in the modified surfaces were detected using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Clot formation parameters were measured using thromboelastography (TEG), a clinically relevant technique to evaluate whole blood coagulation. No polysaccharides were detected in the heparinized polyelectrolyte multilayer-coated titania nanotube array surface (TiO2NT + PEM) incubation solution; however, polysaccharides were detected from NO-releasing TiO2NT + PEM surface (TiO2NT + PEM + NO) incubation solution both after the nitrosation process and after all NO was released. The structures of thiolated chitosan and heparin were altered by t-butyl nitrite. All heparin-containing surfaces were shown to slow or inhibit clot formation. This study is the first to evaluate these endothelial glycocalyx-inspired surfaces using clinically relevant parameters, as well as proposing potential influences of these modified surfaces on the inhibition of clot formation.