Preparation And Application Of Multifunctional Chitin-based Inorganic Composite Sponge

Uncontrollable bleeding is the main cause of early death after trauma,wound infection and healing in post-traumatic treatment is also a very challenging problem.However,the existing hemostatic materials have disadvantages such as poor hemostatic effect,non-degradability,and poor antibacterial properties,which limit their application range.Therefore,it is imperative to develop an absorbable biomedical hemostatic material with low cost and good biocompatibility,which can not only stop bleeding efficiently and quickly,but also inhibit bacterial infection and promote wound healing.Chitin is a rich natural polymer,which is widely used in the fields of hemostasis and wound healing because of its good biocompatibility,biodegradability,and anti-inflammatory activities.However,the traditional pure chitin used as a hemostatic material has insufficient hemostatic effect and low antibacterial activity,which limits the application of chitin in hemostasis and wounds.Based on this,the article uses chitin as a matrix,compounded with different inorganic materials to endow it better hemostatic performance and antibacterial ability.The main research contents are as follows:(1)Study on the hemostatic and antibacterial properties of corn stalk/AuNPs reinforced chitin spongeGold nanoparticles(AuNPs)were synthesized in situ by using corn stalk as the reducing agent and stabilizer.A novel chitin/corn stalk/AuNPs composite sponge(CCAu)was prepared by mixing and cross-linking with chitin.The results showed that the addition of corn stalk improved the softness of the chitin-based sponge.Based on the near-infrared induced photothermal effect of AuNPs,chitin/corn stalk/AuNPs composite sponge has obvious antibacterial activity.The composite sponge has excellent hemostatic effect,the blood coagulation index in vitro was only 15.23%,and the hepatic bleeding was stopped within 49 s,the bleeding volume was 87 mg.Furthermore,in vivo wound healing and in vitro scratch experiments prove that the composite sponge has the effect of promoting wound healing.In addition,cytotoxicity,hemolytic evaluation and tissue sections proved the safety and biocompatibility of the composite sponge.(2)Study on composite hemostatic sponge prepared by chitin intercalate MXeneUsing chitin molecular chain as intercalating agent,MXene was intercalated under ultrasonic-assisted conditions to prepare a new type of chitin intercalated MXene composite sponge(CMX).In order to compare with CMX sponge,a simple blend of chitin and MXene composite sponge(CH+MX)was prepared by simple mixture.The results showed that the two-dimensional layered material MXene with large specific surface area and negative charge has excellent hemostatic effect,especially the hemostatic performance of intercalated MXene is enhanced due to the increase in surface area.CMX15 composite sponge has good performance of blood absorption and hemostasis.The high-speed camera captured whole blood drops within2.8 s,and its in vitro coagulation index was only 2.24%.The hemostasis time was 45 s in the mouse liver hemorrhage model.In addition,the honeycomb composite sponge also has good water and blood absorption properties,degradable properties,photothermal antibacterial properties and good safety.(3)Study on the performance of single-layer MXene/ AuNPs reinforced chitin spongeThe gold nanoparticles were loaded on the exfoliated single-layer MXene nanosheets,further cross-linking with chitin to prepare a novel of multifunctional chitin/MXene/AuNPs composite sponge(CH/s MX@Au).The composite sponge presents a honeycomb structure and has good water and blood absorption properties and good biodegradability.MXene and AuNPs synergize photothermal antibacterial,and the composite sponge has obvious antibacterial activity,which can reduce the risk of wound infection during hemostasis.The single layer of MXene has an excellent hemostatic effect,and the addition of nano-gold further enhances the hemostatic effect.The CH/s MX@Au composite sponge completely absorbed the whole blood drop within 0.9 s,and in vitro coagulation index was only 6.48%.It can stop bleeding in the liver of mice within 34 s,and the bleeding volume was 49 mg,which is significantly better than the commercial PVF sponge.The composite sponge can significantly promote the migration of fibroblasts and keratinocytes and accelerate wound healing.In addition,the composite sponge has excellent biocompatibility,and the cell survival rate of CH/s MX@Au sponge was higher than that of CH/s MX sponge.