Preparation And Performance Study Of Carboxymethyl Chitosan/Chondroitin Sulfate Hemostatic Materials For Medical Use

Excessive bleeding and the resulting serious complications caused by hemorrhage are the main causes of death in war and surgery.Existing hemostatic products exhibit poor adhesion to the wound surface and have difficulty coping with deep wounds such as internal organs and femoral arteries where bleeding is severe,and cannot meet the application requirements.Therefore,the development of rapid hemostatic materials that can be used for deep wounds is of great significance.Carboxymethyl chitosan exhibits antibacterial hemostatic ability;chondroitin sulfate that can promote wound healing is an ideal material for developing tissue adhesives.Therefore,compounding carboxymethyl chitosan with chondroitin sulfate is expected to develop efficient hemostatic materials with good adhesive properties.This study aims to develop medical biomaterials with rapid hemostasis and good adhesive properties based on carboxymethyl chitosan and chondroitin sulfate,which are suitable for deep wounds.Firstly,the cysteamine-modified chondroitin sulfate(CSS)was synthesized by using cysteamine to modify chondroitin sulfate.And the double-bonded carboxymethyl chitosan/cysteamine-modified chondroitin sulfate(Me-CMC/CSS)hydrogel was prepared using thiol-ene click chemistry,and the Me-CMC/CSS dressing was prepared by freeze-drying.The results showed that the Me-CMC/CSS dressing had a three-dimensional porous structure.The optimal relative clotting index of the Me-CMC/CSS dressing was 42.29±6.01%,which was 53%(p<0.001)lower than that of the Me-CMC dressing and 29%lower compared to the commercial hemostatic gelatin sponge.In a rat liver hemorrhage model,the Me-CMC/CSS dressing achieved rapid hemostasis with lower total blood loss than the gelatin sponge and a significant 92%reduction compared with the untreated group(p<0.0001).Platelet adhesion assays showed that the Me-CMC/CSS dressing exhibited a higher ability to adhere to platelets than the gelatin sponge.In addition,the Me-CMC/CSS dressings exhibited good hemocompatibility and cytocompatibility.The above results showed that the Me-CMC/CSS dressing has the potential to be used as a rapid hemostatic material.Secondly,because the Me-CMC/CSS dressing is not suitable for irregular tissue defect sites and deep wounds,a carboxymethyl chitosan/catechol-modified oxidized chondroitin sulfate(CMC/OCS-DA)injectable hydrogel was constructed by introducing aldehyde and catechol groups sequentially on the chondroitin sulfate molecular chain,followed by Schiff base reaction.The catechol-modified oxidized chondroitin sulfate(OCS-DA)was synthesized by using sodium periodate and dopamine to modify chondroitin sulfate sequentially.Then the CMC/OCS-DA hydrogels were prepared by rapid in situ cross-linking of carboxymethyl chitosan with OCS-DA,and their performances were evaluated.The results showed that the CMC/OCS-DA hydrogels had a looser three-dimensional porous structure,better swelling properties,and better self-healing ability compared with the carboxymethyl chitosan/oxidized chondroitin sulfate(CMC/OCS)hydrogels.Lap shear model showed the bond strength of the CMC/OCS-DA hydrogel to pigskin was 16.6 kPa,which was significantly higher by 36%compared with the CMC/OCS hydrogel(p<0.05).A mouse gastric ulcer model in vitro showed that the CMC/OCS-DA hydrogel could adhere to the surface of mouse gastric tissues and effectively seal gastric perforations.In addition,the CMC/OCS-DA hydrogel could bond pig livers or pig bones together.In a rat liver hemorrhage model,the CMC/OCS-DA hydrogel achieved rapid hemostasis with a 90%(p<0.001)and 56%(p<0.05)reduction in total blood loss compared to the untreated group and the CMC/OCS hydrogel group,respectively.It showed that the introduction of catechol moieties significantly improved the hemostatic properties of the CMC/OCS hydrogel.In addition,the CMC/OCS-DA hydrogels exhibited good hemocompatibility and cytocompatibility.The above results suggested that the CMC/OCS-DA injectable hydrogel can rapidly stop bleeding and exhibit good adhesive properties and biocompatibility.In summary,the Me-CMC/CSS dressing for rapid hemostasis and the CMC/OCS-DA injectable hydrogel for deep noncompressible wounds hemostasis were successfully prepared in this research,which provides an idea for the development of carboxymethyl chitosan/chondroitin sulfate-based hemostatic materials.