Co-assembled biomimetic fibrils from collagen and chitosan for performance-enhancing hemostatic dressing.

The development of safe and efficient hemostatic materials is medically important to prevent death due to trauma bleeding. Exploiting the synergistic effect between the D-periodic functional domain of collagen fibrils on platelet activation and cationic chitosan on erythrocyte aggregation is expected to develop performance-enhanced hemostatic materials. In this study, we prepared collagen fibrils and chitosan composite hemostatic materials by modulating the self-assembled bionic fibrillation of collagen with different degrees of deacetylation (DD, 50%, 70% and 85%) of chitosan. The findings indicated that chitosan promoted collagen self-assembly, with all the collagen fibrils demonstrating a typical D-periodical structure similar to that of the native collagen. Furthermore, the composite demonstrated enhanced structural integrity and procoagulant capacity along with good biocompatibility. Notably, the fibrillar composites with 70% DD of chitosan exhibited optimal mechanical properties, procoagulant activity, and adhesion of erythrocytes and platelets. Compared to pure collagen fibrils and the commercial hemostatic agent Celox™, the collagen/chitosan fibrillar composite treatment significantly accelerated hemostasis in the rat tail amputation model and liver injury model. This research offers new insights into the development of hemostatic materials and indicates that collagen-chitosan composites hold promising potential for clinical applications.