Abstract:
Hemorrhage is a major contributor to avoidable fatalities worldwide. It occurs when there is excessive blood loss due to accidents, battles, or surgical procedures. The preparation of rapid hemostatic materials along with strong bactericidal property and minimum erythrocyte lysis for deep hemorrhage still remains a challenge. Herein, a series of novel microparticle hemostats made with different polysaccharides such as chitosan, starch, cross linked with unoxidized tannic acid was prepared via hydrothermal treatment and facile ionic gelation method. Hemostats' comparative functional properties, such as adjustable antibacterial and erythrocyte compatibility upon various starch additions were evaluated. The chemical bonds between the constituent materials were verified by ATR-FTIR. The microparticles had excellent hemostatic property and could concentrate blood cells, blood proteins and clotting factors as well as could induce electrostatic interaction between positively charged chitosan and negatively charged blood cells. Blood clotting index (BCI), red blood cell (RBC) adhesion was performed to verify its hemostatic capability for in vitro study. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were employed to find out the composite’s hemostatic mechanism. For in vivo hemostatic study, mice liver laceration and rat tail amputation were performed to evaluate the composite’s efficacy in real injury scenario. The in vivo hemostatic study reveals that the developed hemostats for mouse liver laceration and rat tail amputation had clotting times (13 s and 38 s, respectively) and blood loss (51 mg and 62 mg, respectively) similar to those of CeloxTM. These studies suggest that the prepared microparticles can be employed in deep wound to halt bleeding. The erythrocyte adhesion test demonstrated that erythrocyte lysis can be lowered by modifying the antibacterial hemostats with different starches. Antibacterial efficacy of the hemostats remained intact against S. aureus (>90%), E. coli (>80%), and P. mirabilis bacteria upon starch modification. In comparison with CeloxTM, which does not have any antibacterial property against gram negative bacteria, the developed hemostats microparticles have broad-spectrum antibacterial activity. They also demonstrated high hemocompatibility (<3% hemolysis ratio), moderate cell viability (>81%), in vivo biodegradation, and angiogenesis indicating adequate biocompatibility and wound healing. These results suggest that the developed series of microparticle hemostats have a great promise as rapid hemostatic agent with strong antibacterial property to be used in emergency situations for preventing massive hemorrhage.