Marine collagen peptide grafted carboxymethyl chitosan: Optimization preparation and coagulation evaluation

Uncontrolled bleeding has always been a sudden accident, which is the main cause of casualties in war trauma, emergency events and surgical operations. Rapid hemostatic materials can effectively reduce casualties and save lives. In this paper, marine collagen peptide grafted carboxymethyl chitosan (CMCS-MCP) was synthesized by 1-ethyl-(dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. To obtain CMCS-MCP conjugates with different degrees of substitution (DS), the reaction conditions were investigated by single-factor tests and optimized by response surface methodology. And the sponges of CMCS-MCP were prepared by freeze-thaw cycling and freeze-drying and characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), and X-ray diffraction (XRD). To evaluate the hemostatic properties of CMCS-MCP sponges, in vitro and in vivo hemostasis tests were carried out. The results showed that the optimum preparation conditions were the mass ratio of MCP to CMCS (M_MCP/M_CMCS) 6:1, reaction temperature 41 °C, and reaction time 16 h. And under which the DS of 58.86% was obtained. Structure analysis showed that MCP had been successfully grafted onto the CMCS molecular chain, and the CMCS-MCP sponges were of high porosity. In vitro and in vivo hemostasis tests showed that the CMCS-MCP sponges had significant procoagulant activities, especially the one with high DS of 58.86%. The hemostasis mechanism may be that the synergistic effects of MCP and CMCS accelerated coagulation through multiple approaches. The CMCS-MCP sponges give a new insight into biomedical hemostasis materials.