Chitosan-based composite hemostatic material :
Owing to the superior properties of hemostasis, antibacterial, anti inflammatory, wound healing, biocompatibility, biodegradability, and nontoxicity. Chitosan was expected to be an excellent hemostatic agent. Nevertheless, hemostatic materials with chitosan alone have limited hemostatic effects, To improve the hemostatic performance, Chitosan-based composite material has been prepared by blending chitosan with other functional components. which can act synergistically to realize fast and effective hemostasis As chitosan can be easily processed into various forms chitosan-based composite materials have been made into various forms of sponges, films, hydrogel particles, and fibers. In recent days more and more chitosan-based materials have been developed.
A. Chitosan-based composite hemostatic films: In recent years chitosan and gelatin have been generally used as hemostatic dressings. Chitosan is an abundant natural alkaline polysaccharide that can accelerate blood coagulation and facilitate tissue growth and wound healing. Gelatin is a macromolecular hydrophilic colloid obtained by partial hydrolysis of collagen and has been widely used in food cosmetics and medicine with other fields due to its unique physicochemical properties. Preparation of ibuprofen chitosan/gelatin composite films using the solvent casting method The results indicate that the amount of chitosan in the composite films directly affected the tensile strength and the elongation at break.
B. Chitosan-based composite hemostatic sponges. As promising biomaterials for hemostasis, biodegradable sponges have been clinically required in the last decade.
With the development of medical services, the requirement of hemostatic materials are increasing. It is of great significance to fabricate fast efficient safe and ready to carry novel hemostatic materials.
Thus it is necessary to study the hemostatic mechanism systematically and synergistic effects of chitosan and chitosan-based hemostatic materials. Various hemostatic materials with different homeostatic mechanisms may be incorporated together to give full play to advantages of different materials, increase hemostatic pathways, accelerate the hemostatic speed, and eventually achieve fast hemostasis. Meanwhile, the hemostatic effects of hemostasis vary with their forms. The forms of chitosan-based composite material can be optimized to obtain fast hemostasis Meanwhile the hemostatic effects of hemostats vary with their forms. The form od chitosan-based composite materials can be blended with other functional components such as pain-relieving anti-inflammatory wound healing materials to obtain chitosan-based multifunctional composite hemostatic materials.
The liver is the most commonly injured abdominal organ causing hemorrhagic death and the most frequent source of uncontrolled hemorrhage requiring reoperation .. Grade 5 hepatic injuries are classified by the liver injury scale of the American Association for the surgery of trauma involve extensive parenchymal damage combined with a major vascular laceration. Most reported mortality rates for these injuries are greater than 60 %. currently the most effective measures and method for treating grade 5 liver injuries to be packing abdomen with gauze sponges to achieve tamponade for reopening of the packing removal at a later time.
An effective hemostatic dressing could augment correct methods for control of this severe form of hemorrhage. Recently a freeze-dried chitosan-based dressing has been developed. The chitosan dressing has been designed to develop the mucoadhesive surface density and structural integrity of chitosan at the site of injury. Using the model of severe hepatic trauma and vascular injury in the spine we examined the effect of free dried chitosan-based dressing on blood loos and short term survival. Post-treatment blood loss was significantly reduced in the chitosan dressing group. In previous studies using chitosan as hemostatic agents topical applied liquid chitosan with normal hemostatic function with impaired platelet function and impaired blood coagulation.
Liquid chitosan was used to control the diffuse capillary bleeding in brain tissue in the feline model. Microcrystalline chitosan has been used for sealing arterial puncture sites after catheterization. Other chitosan and chitin have been formed into thin sheets and used for hemostats. An 80 % chitosan membrane reduced bleeding after visceral and parietal peritoneal abrasion. More recently fully acetylated chitin sheets shortened time to hemostats compared with commercially available absorbable collagen and oxidized cellulose hemostatic products in deep laceration of spleen of siwn model. So hemostatic activity of chitosan is great as compared to steroids which caused various side effects such as dizziness.