Preparation And Properties Of Silver-loaded PVA/CMCS/SA Composite Hydrogel Wound Dressing

Wound dressing can provide an environment suitable for wound healing during wound treatment,and at the same time play a protective role in the barrier.However,the traditional wound dressings have the many disadvantages such as easy adhesion to the wound surface,poor barrier effect,and poor hemostatic effect.Therefore,in view of the disadvantages of traditional wound dressings,it is of great significance to design a new type of wound dressing that has no damage to wounds,has good antibacterial effect,and promotes wound healing.In this paper,polyvinyl alcohol(PVA),carboxymethyl chitosan(CMCS)and sodium alginate(SA)were selected as the raw materials for constructing hydrogel wound dressing.Nano-silver was prepared by in-situ reduction method,and nano-silver was compounded into PVA/CMCS/SA hydrogel.Based on molding method and 3D printing manufacturing method,silver-loaded PVA/CMCS/SA hydrogel wound dressing was constructed.The microstructure,micromorphology,mechanical properties,moisture absorption rate,biocompatibility,antibacterial properties,and in vitro coagulation properties of hydrogel wound dressings were studied.The results show that the hydroxyl groups on the sodium alginate chain are reductive.It is oxidized to a carbonyl group when heated at 90?and protected from light,and silver ions(Ag~+)are reduced to elemental nano silver(Ag~0).At the same time,the free carbonyl group in the water can effectively control the nucleation and growth of nano-silver and act as a stabilizer.The silver nanoparticles prepared by sodium alginate as a reducing agent and stabilizer have a small and uniform particle size,with a particle size range of 8-46 nm.Nanosilver particles with a particle size of about 12 nm account for 50%,which meets the requirements of antibacterial.The silver-loaded PVA/CMCS/SA hydrogel wound dressing prepared by the molding method has uniform pores inside,and have good water absorption and moisture retention,which can absorb a large amount of wound exudate while maintaining a moist wound environment.Silver-loaded hydrogel wound dressing has good static and dynamic mechanical properties,tensile strength up to 300 KPa,It is soft and ductile,can withstand multiple stretches or compressions,and performs well elastic properties under different stress,frequency and temperature changes.It has good antibacterial properties against S.aureus and E.coli and can continue to be antibacterial.The inhibition rate of escherichia coli and staphylococcus aureus was52%and 42%,respectively.And there is no cytotoxicity,the relative survival rate of cells is higher than 83%.In addition,the silver-loaded hydrogel wound dressing can effectively shorten the coagulation time to absorb part of the blood,but the adsorption capacity of the blood is poor.Compared with hydrogel wound dressing prepared by molding method,silver-loaded PVA/CMCS/SA hydrogel wound dressing prepared by 3D printing method has better dimensional and structure stability.The 3D printed silver-loaded PVA/CMCS/SA hydrogel wound dressing has good tensile properties.The tensile strength has remained at a high level,and it can even reach more than 900 KPa.At the same time,the cyclic stretching and cyclic compression properties are significantly improved.Due to the 3D printed grid structure,the water absorption,moisture retention,in vitro coagulation performance,breathability and antibacterial performance of the 3D printed hydrogel wound dressing have been significantly improved.The inhibition rate of E.coli and S.aureus was 64%and 54%,respectively.The 3D printing method can combine the hydrogel with the woundplast,which ensures the practicality of the wound dressing.In summary,the silver-loaded hydrogel PVA/CMCS/SA wound dressing has good mechanical properties,water absorption and moisturizing properties,antibacterial properties,biocompatibility and blood coagulation properties.The paper has 55 pictures,7 tables,and 88 references.