11.3.3　Hemostatic fiber dressings

Traditional hemostatic materials and products are mainly hemostatic gauze，bandages，and hemostatic sponges.Clinical applications have found that these products have poor hemostatic effects and do not have the ability to actively stop bleeding.They can only meet the hemostatic needs of general or conventional bleeding wounds，and they are not degradable in the body.It is difficult to be absorbed by the body，therefore their applications are quite limited.In recent years，scientists have discovered that the surface modification of gauze，sponge，etc.，with a layer of porous，soft，and water-absorbing fibers with excellent adhesion and blood coagulation will greatly improve their hemostatic properties.For example，Hammond et al.loaded RADA16-I self-assembled polypeptide nanofibers on the surface of gauze or gelatin sponge through layer-by-layer assembly technology to obtain a fast hemostatic gauze or sponge with active coagulation function.Since RADA16-I self-assembled polypeptide nanofibers can effectively aggregate and cross-linking components in the blood，the hemostatic effect of gauze or sponge is greatly improved.Yu et al.prepared hybrid electrospun poly（vinyl pyrrolidone）fibers with curcumin-loaded mesoporous silica for rapid hemostasis and antibacterial wound dressings.It is found that the nanofiber mat has no obvious toxic effect on cell growth，and can enhance the antibacterial effect on S.aureus in vitro.In addition，the hybrid nanofiber mat could quickly turn into hydrogel when in contact with blood and then activated the coagulation system to prevent bleeding from the wound.

In addition，based on improving the hemostatic effect of the materials，further optimization of the preparation process has also aroused the widespread interest of scientific researchers.Long et al.developed a portable electrospun device（about 150 grams）for outdoor use，which can realize the green synthesis of CuS composite nanofibers.These composite nanofibers can be deposited on the wound in-situ while achieving rapid hemostasis and elimination of super bacteria outdoors without the use of other materials or equipments.The compactness of this in-situ electrospun nanofiber on the rough surface of the wound is better than that of the traditional nanofiber pad pressed on the wound.Therefore，nanofibers can not only accelerate hemostasis（＜6 s），but also shorten the healing time of superbacterial infection wounds（18 days）.These dual-function nanofibers combined with portable electrospun equipment can be used for outdoor rapid hemostasis and simultaneous ablation of super bacteria，which can significantly improve outdoor first aid（Figure 11-15）.(https://www.daowen.com)