Hemostatic Needles: Controlling Hemostasis Time by a Catecholamine Oxidative Pathway

Abstract

Most infectious human viruses are generally found in the bloodstream after being released by infected organs. Thus, hemorrhage in patients, whose blood contains infectious viruses might be a significant risk for secondary infections. In this work, a self-sealing hemostatic needle that causes no bleeding even after its removal is reported. The materials used for the self-sealing needles are inspired by mussel adhesive polysaccharide, chitosan-catechol, which shows a rapid phase transition from a solid phase (i.e., a thin film) to an adhesive gel upon coming into contact with blood. We found that the self-sealing time for the complete hemostasis depends on the oxidation pathway of the conjugated catechol. For high-temperature oxidation (i.e., 60 degrees C), Michael addition is a dominant oxidative coupling reaction, which weakens the chitosan-catechol attachment force on the needle surface. Thus, the film is easily transferred to the hemorrhaging sites, with the result that there is no bleeding even after a short injection time (<5 s). In contrast, during low-temperature oxidation (4 degrees C), Schiff base formation is dominant, which strengthens the film attachment force on the needle surface, resulting in continued bleeding owing to a dearth of tissue transfer after the injection.