| BACKGROUNDPromoting wound healing has been a very hot research topic in thesurgical field. Among them, the treatment of infecting wound is one of themost important part. Not only undermining the local normal tissue, delayingwound healing, infecting wound can also cause serious complications, andadverse impacts on the patient’s general condition. Therefore, the control ofwound infection, strengthening antibacterial, has become the focus of thestudy.Currently, patients are commonly used antibiotics through oral orintravenous infusion or dressing on the infecting wound. Although antibioticsdressings act rapidly, long-term use of antibiotics may have a bacterialresistance. nAgACF dressing can well solve both antibac terial and drugresistance two issues.Nano Silver is the traditional silver being produced as nanoscale particles.Because of antibacterial activity of the silver and such as smal l size effect ofthe specificity, quantum effects, surface effects of the nanotechnology,nAgACF dressing bactericidal activity will be improved several times. Andhigh security, it is a long-lasting and antimicrobial agent. In addition, nanosilver is non-antibiotic bactericidal agent. There is no any bacterial developingresistance to silver.Activated carbon fiber is a new functional fiber based on organic fibers asprecursor, having good formability, good acid, alkali resistance, electricalconductivity and chemical stability. Not only have it the large specific surfacearea, aperture moderate, evenly distributed and the faster absorption speed, buthas a different shape.nAgACF dressing is a new anti-infective dressings imbedding nano scalesilver into internal activated carbon fiber by iron exchange. Studies haveshown that loading the appropriate amount of silver on the activated carbonfiber material, can effectively kill microorganisms, and inhibit the propagationof microorganisms in the activated carbon fibers. In this way, it not only playexcellent adsorption performance of activated carbon fiber, but also increase the inhibitory bactericidal function of the activated carbon fiber.OBJECTIVE1. This study is to design observing antibacterial effect of nAgACFdressings out of the body and clearing its antibacterial ability.2. Through animal experiment, it verify antibacterial and promotingwound healing effect of nAgACF dressings to provide a reference for clinicalapplication.METHOD1. Zone of Inhibition Method Incubated for18~24h blood agar, picking4～5colonies, was made of a bacterial suspension of1×104cfu/ml. Cottonswab is dampened with a bacterial suspension to the M-H plate according tothe three directions (turn60°) desecration, in order to ensure uniformdistribution of inocula. Inoculated with bacterial, until the surface water ofagar is slightly evaporating, then was pasting different kinds of dressing filmof10mm in diameter. After15min being into the incubator at35°for18~24h,then measure the results.2.Plate Counting Method A shaking flask experiment was set that0.75gnAgACF dressings, nano silver dressings, carbon fiber dressings, as well asordinary dressings were placed in a250ml flask, and then70mlPBS and5ml o fbacterial suspension were added into the flask, so that the concentration ofbacterial suspension was1×104cfu/ml. Taking the0.5ml of flask oscillationafter the1hour was tilting petri dish, then count and calculated theantibacterial effect.3.Animal experiments Establishing the infecting wound rat model; allwound were divided into four groups (experimental group: nAgACF dressings,control group: nano-silver dressing, the activated carbon fiber dressing,ordinary dressing). Regular medication, culturing wound bacterial, measuringsize of wound and removing samples of tissue to pathological observation weretreated to rat. Wound was compared with general condition, inhibition rate,rate of healing, inflammatory cell, fibroblasts under the microscope.RESULT1. There is no obvious zone of inhibition in the carbon fiber dressings andordinary dressings. The mean zone of inhibition of nano-silver dressings to EC, SA, PSA were13.4mm,11.5mm,10.6mm, The mean zone of inhibition ofnAgACF dressings to EC, SA, PSA were respectively14.6mm,12.7mm,11.5mm. Comparing with the control group, the largest zone of inhibition wasnAgACF dressings. There was statistically significant (p <0.01).2. Mean inhibition rate to EC、SA、PSA, nAgACF dressings were83.42%,82.14%,78.10%, the nano-silver dressings were74.75%,73.36%,71.72%,carbon fiber dressings were4.52%,7.71%,6.68%,ordinary dressing s were2.67%,3.62%,3.6%. Compared with the control group, three bacterialinhibition rate of nAgACF dressings were highest. There was statisticallysignificant (p <0.01).3. General observation, dietary, intake of water and activities of rats ofnAgACF dressings were better than the other three group. There was noobvious difference in wound inhibition rate and healing rate in the3rd and7thday. Wound inhibition rate and healing rate of nAgACF dressing group werehigher than the other three group in14th day and21th day. There wasstatistically significant (p<0.01). Through wound pathological observation,inflammatory cells of nAgACF dressings group were less than the other threegroups. The fibroblasts and collagen fibers were more than the other threegroups. There is no local sensitization and systemic symptoms.ConclusionThe nAgACF dressings have a good antibacterial effect out of body,anti-infective and promoting wound healing effect to experimental animal.Through animal experiments, it verify the nAgACF dressings have shown asignificant advantage through inhibition rate to EC, SA and PSA, rate ofhealing as well as accelerating proliferation of epithelial cell comparing toother dressings. It was an ideal dressing in the clinical application. |
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