Preparation And Properties Of Novel Antibacterial Dextran Based Hydrogel Wound Dressings

Skin is one of the largest organs,which is likely to suffer due to exposure to the external environment for a long time.Superficial burns usually fast heal with minimal scarring,but econdand third-degree burn injuries which damage the skin the epidermis layer and dermis layer are hard to heal automatically.Treatments for second-and third-degree burn injuries remain far from optimal.The selection and preparation of effective wound dressings have become a serious problem.Hydrogels are materials that when placed in excess water swell rapidly and retain a large volume of water in their swollen three-dimensional structure withoutdissolutionare and its is similar to natural extracellular matrix in the structure,so the hydrogel wound dressing is very suitable to the requirements of an ideal dressing.In this paper,three hydrogel wound dressings with different crosslinking density were prepared by crosslinking double bond using dextran as raw materials,including quaternary ammonium not grafted on to dextran chain(Dex-SA-DAMA hydrogel),quaternary ammonium grafted on to dextran chain(Dex-GTMAC-SA-DAMA hydrogel),quaternary ammonium grafted on to dextran chain and chlorhexidine preparing loaded(Dex-GTMAC-SA-DAMA CHX loaded hydrogel).The basic properties of the hydrogels were studied and analysed;The hydrogel dressings' biological properties were studied through the antibacterial experiment and cell test;In order to investigate its wound healing effect,animals test in vivo were proceeded.By SEM and swelling rate test,it is proved that all of the hydrogels exhibit a highly porous honeycomb-like and three-dimensional network structure,which is conducive to the growth of cells,oxygen exchange,waste discharge and prevention of the bacteria invasion;The water absorption capacity of hydrogels have reached more than 8 times,which demonstrates that the excess wound fluids can be absorbed without dissolution;The data of mechanical properties test indicate that both of the hydrogels provide enough and flexible strength for covering the wound without deformation or damage;The anti-protein adsorption test shows that the hydrogels have good anti-protein ability.By the degradation experiments,it is shown that hydrogels can be degraded which is beneficial to environment.The drug release in the hydrogels prove that Dex-GTMAC-SA-DAMA hydrogel can release the drug slowly with efficient drug loading which can be used as medicine compound dressings.The data of antibacterial experiment shows that Dex-GTMAC-SA-DAMA CHX loaded hydrogel shows more excellent antimicrobial property than Dex-GTMAC-SA-DAMA CHX unloaded hydrogel,while Dex-SA-DAMA hydrogel doesn't show any antimicrobial property.The cell experiment showed Dex-GTMAC-SA-DAMA CHX unloaded hydrogel shows better biocompatibility than Dex-GTMAC-SA-DAMA CHX loaded hydrogel,but both of them have no cytotoxicity,which means that both of the hydrogels do not have any effect on cell proliferation.The animal experiments show that the Dex-GTMAC-SA-DA-MA hydrogel dressings can effectively greatly shorten the healing time and accelerate the healing of the wound,whether or the drug is loaded or not.It is demonstrated that the hydrogels are expected to become a novel biocompatibility and antibacterial wound dressing in medical application.