Preparation And Properties Of Graphene/Carboxymethyl Chitosan Hemostatic Composite Gel Sponge

Rapid and effective hemostasis is the key to controlling hemorrhage and reducing battlefield and daily life mortality.In recent years,graphene oxide(GO)has received more and more attention in the field of hemostasis due to its unique physicochemical properties.GO can be used to stimulate platelets and cause strong platelet aggregation.Proven to cause adverse effects both in vivo and in vitro.L-cysteine is a common mild amino acid,and the groups on the surface react with the active groups on the surface of graphene oxide,which can be used to improve the biocompatibility of graphene oxide.Carboxymethyl chitosan and carboxymethyl cellulose have excellent biocompatibility,natural non-toxicity and antibacterial properties.It is expected to prepare hemostatic materials with better hemostatic effect through the combination of several materials.The first step is to prepare an optimal ratio of carboxymethyl chitosan(CMCS)/carboxymethyl cellulose(CMC)composite gel sponge through an ionic and chemical double-crosslinking system.The first part optimizes the content of a large number of basic components,takes the liquid absorption performance as the check point,and obtains the formula with the best liquid absorption performance.When the content of carboxymethyl chitosan is 2.0 g and the carboxymethyl cellulose is 0.5 g,When the content of genipin was 10 mg,and the content of glycerol and calcium chloride were 2.0ml and 0.2 g,respectively,the liquid absorption rate of the gel sponge reached about1900%.In addition,the mechanical properties of the gel sponge are over 200 k Pa,the porosity is over 90%,and it has good anti-swelling properties..The second part is to introduce graphene oxide(GO)into the carboxymethyl chitosan(CMCS)/carboxymethyl cellulose(CMC)composite gel system.The structure of the gel sponge was characterized by FTIR and SEM,and the optimal incorporation value of graphene oxide(GO)was determined by testing the liquid absorption rate,porosity,swelling rate and mechanical properties.The results show that when the graphene oxide content reaches 0.15 g,the mechanical properties are the best at 400 k Pa,the liquid absorption rate is as high as 3674 %,the porosity reaches 94.7%,and the anti-swelling performance is far better than that without graphene oxide.The third part of the work is the chemical modification of graphene oxide by Lcysteine,and the effect of the content of L-GO after modification on the various properties of the gel sponge is explored.Extensive biological experiments were performed to evaluate three groups of hemostatic gel sponges.The successful modification of graphene oxide by L-cysteine was determined by FTIR,and the optimal component content of L-GO was explored through liquid absorption properties and porosity.The results show that the liquid absorption and porosity are optimal when the L-GO content is 0.10 g.Through biological healing experiments,antibacterial experiments,hemostasis experiments,cytotoxicity experiments,etc.,it can be seen that the modification of graphene oxide by L-cysteine reduces its toxicity,and has close antibacterial properties to GO.The L-GO/CMCS gel sponge has the best healing effect,the hemostasis time is shortened from the original 70 s to about 20 s,and the blood loss is also reduced from 0.16 g to 0.06 g.In conclusion,the L-GO/CMCS gel hemostatic sponge fabricated in this paper has excellent application prospects in biomedicine.