Preparation Of Electrospun Nanoscale Silver I Carbon Nanofibers Composite Dressing And Research On Antibacterial Property

1. Researching BackgroundEvery year, there are millions of people who are burned or scalded because of hot water,flames and boiling oil around the world. Medical dressing can provide a perfect environmentfor the burning surface and plays an key role in wound healing. Though many wounddressing have been used in clinical practice, few could satisfy so many requirements ofwound healing. For example, cotton swab can absorb liquid on the wound, but isn’tcompetent in disinfection and wound healing promotion. Another example, animal skin(hogskin) can promote the growth of tissue, but it is expensive to be used widely. So what is finewound dressing comes to tow aspects, disinfection and wound healing promotion.Nanofiber structure prepared through electrospinning technology has similarity withnatural extracellular matrixc(EMC), which is continuous microfiber and has high ratio insurface volume, interspace and variable pore size distribution. It is confirmed by experimentsthat it can simulate EMC structure, stimulate cells to synthetize cell factors and growthfactors and promote wound healing. It has wide source and can be prepared ahead of time.According to biological functions, all kinds of imitated ravine organization structure can bemade. However, nanofiber dressing alone doesn’t have antibacterial capacity. So only bychoosing proper antimicrobial Ag+ents and combining it with nanofiber dressing, can perfectburning wound dressing be made. As to antimicrobial Ag+ents, nanoscale silver has betterantibacterial capacity which has super resistance to medicine and allergy and is safer. Manykinds of nanofiber dressing and nanoscale silver have been put into clinical practice.2. Researching Purpose\2.1Through preparing nanofiber dressing and nanoscale silver using electrospinningtechnology, we can observe the macro and micro structures.2.2Though in vitro experiments, study its antibacterial capacity for further study inpreparation of burning wound dressing which provide a experimental basis for further studyand clinical practice.3. Researching Steps and MethodsIn the research polyacrylonitrile(PAN) was used for precursor, by applyingelectrostatic spinning technology and high temperature carbonization method carbon nanofibers were prepared. But whether this material can meet the requirements of perfectburning dressing is still unknown, so antibacterial activity of such composite fiber dressingis to be evaluated.3.1The preparation and detect of nanoscale silver/carbon nanofibers composite. In theresearch polyacrylonitrile(PAN) was used for precursor. Use15kv spinning voltAg+e, witha distance of15cm between pin head and receiver board. By pre-oxidation and thermalcracking, PAN nanofiber becomes carbonized into carbon nanofibers. Assisted by silvermirror reaction, nanoscale silver/carbon nanofibers composite is prepared.3.2Use scanning electron microscopy(SEM) to observe its micro structure. Use EDXspectrum to analysis whether there is nanoscale dilver on the surface.3.3Research on the antibacterial capacity of nanoscale silver/carbon nanofibers composite.By using Kirby-Baucer method, antibacterial extrasomatic test was conducted with these twosamples and gentamicin scraps of paper and urgotul. Watching the composite dressing’santibiotic property on one week.4. Results of the researchThe main results and conclusions are as follows:4.1In the research polyacrylonitrile(PAN) was used for precursor, by applyingelectrostatic spinning technology and high temperature carbonization method carbonnanofibers were prepared.4.2The morphological characterization of nanoscale silver/carbon nanofibers composite:the diameter of carbon nanofiber is200nm~300nm, fibers are relatively straight, discrete andsmooth on the surface. By silver mirror reaction at room temperature, the diameter increasedto300nm~400nm, and its surface became rough. EDX spectrum showed that on the surfaceof carbon fiber there is a layer of nanoscale silver granules.4.3Using Kirby-Baucer method proved:1)nanoscale silver/carbon nanofibers compositeand urgotul have good effects on Staphylococcus aureus, E.coli and pseudomonas aeruginosa,but inferior to standard susceptibility paper of antimicrobial Ag+ents.2) the nanoscale silver/carbon nanofibers composite and urgotul had good antimicrobial effects to Staphylococcusaureus,E.coli and Pseudomonas aeruginosa;the composite nanofibers was better than urgotulat Pae and Sau.3) In the test, nanofibers are showed to have antibacterial capacity.By using Kirby-Baucer method, with a week’s continuous observation, we find thecomposite has obvious effect on Pseudomonas aeruginosa, with days go on, its effectdeclines till the third day, but has lasting effect on Staphylococcus aureus and E.coli in a week.5. Conclusion:Nanoscale silver/carbon nanofibers composite has similar porous structure as that ofECM at nano-level, has good antibacterial capacity and histocompatibility. This studyprovides a new method for burning surface dressing.