The Preparation And Antibacterial Performancec Study Of Peptide Modified Cellulose Acetate Nanofibers

With the continual development of textile science and technology,traditional textile can no longer meet the needs of life.People hope that textile not only has the function of keeping warm and beauty,but also hope has some additional effects,such as antibacterial effects,self-cleaning,moisture conductivity and other properties.In the process of wearing,textile is very easy to contaminate by the body’s secretion of perspiration and body fluids.The moist and warm environment is the breeding environment of bacteria and other microorganisms.Therefore,if the textile is given the antibacterial properties,the textile not only can prevent bacteria and other microorganisms spreading in the textile,but also protect textile from microbial erosion.Antibacterial textile using traditional production method has the problem of early release of antimicrobial agents,the evanescent of antimicrobial effect and the potential harm of nano-particles antibacterial agents to the human body.Therefore,the antibacterial agent can be combined with the textile material through chemical grafting to avoid the agglomeration of the nano-antibacterial particles and the brought by the problem of non-uniform antibacterial effect from blended spinning.In this paper,antimicrobial peptides are used as antibacterial agents,which are grafted onto cellulose acetate to prepare modified cellulose acetate.The electrospinning are used to prepare the modified cellulose acetate nanofibers.The antibacterial property of the nanofibers is studied.The antibacterial stability is also explored,which lay the foundation of their future research in the field of biomedicine.First of all,according to the specific amino acid sequence,the solid phase synthesis is used to synthesized the antimicrobial peptides.The chemical structure of antimicrobial peptides are verified by IR and 1H NMR.Then,in the process of electrospinning,the optimum technological parameters of CDA are explored from three aspects:solution concentration,spinning voltage and receiving distance.When the concentration of the solution is 10%,the spinning voltage is 15kV and the receiving distance is 20cm,the cellulose acetate nanofibers are uniform.Under these optimal spinning process parameters,CDA/peptide nanofibers are prepared by blended spinning.The appearance,chemical structure,mechanical properties and thermal stability are studied.The antibacterial activity of antimicrobial peptides and CDA/peptide nanofibers against E.coli and S.aureus are chiefly studied.The results show that the antibacterial rate of the antimicrobial peptides are 99.5%and 99.7%and the antibacterial rates of CDA/peptide nanofibers are 97.8%and 98.1%.Both materials have excellent antibacterial activity performance.Then the antibacterial stability of CDA/peptide nanofibers are studied.The results show that with the increase of oscillation time,the antibacterial rate of CDA/peptide nanofibers against E.coli and S.aureus are decreased.It means the antibacterial stability of the CDA/peptide nanofibers is poor.In order to solve the problem of poorly antibacterial stability of the CDA/peptide nanofibers,a chemical grafting method is used to combine the antibacterial peptide with the CDA,and then the nanofibers were prepared by electrospinning.The carboxylated cellulose acetate is grafted with the antimicrobial peptides to prepare the CDA-g-peptide.Both IR and ~1H NMR spectra show that the antimicrobial peptides have been grafted onto CDA.X-ray diffraction test shows that the crystalline structure of the CDA-g-peptide is mainly amorphous,almost the same as that of CDA.Thermogravimetric analysis shows that CDA-g-peptide has better thermal stability than CDA.The antibacterial activity of CDA-g-peptide are tested by E.coli and S.aureus.The results show that the antibacterial rate of the material on the test strains are 98.6%和98.8%.The CDA-g-peptide has excellent antibacterial properties.Under these optimal spinning process parameters,CDA-g-peptide nanofibers are prepared.The appearance,chemical structure,mechanical properties,thermal stability and antibacterial properties are studied.In terms of appearance,the CDA-g-peptide nanofibers have a narrower diameter distribution and a more homogeneous fiber membrane.The chemical functional groups of the CDA-g-peptide nanofibers are consistent with the spinning raw materials.The maximum elongation of the CDA-g-peptide nanofibers is similar with that of the CDA/peptide nanofibers,but there is a certain difference in the maximum tensile load.However,the thermal stability of CDA-g-peptide nanofibers is better than that of CDA/peptide nanofibers.In terms of antibacterial properties,the growth curves of E.coli and S.aureus are studied,which are the growth and reproduction of bacterias within 24 hours.Then the CDA-g-peptide nanofibers’antibacterial rate are tested,the results show that the CDA-g-peptide nanofibers have excellent antibacterial properties.Finally,the antibacterial stability of CDA-g-peptide nanofibers are studied.Then the CDA-g-peptide nanofibers are dealed with the water bath oscillating treatment to explore the changes of the antibacterial rate of the nanofibers with the oscillation time increasing.The results showsd that the antibacterial rate of CDA-g-peptide nanofibers is constant with the increase of oscillation time,while the antibacterial rate of CDA/peptide nanofibers decreases.Therefore,CDA-g-peptide nanofibers have good antibacterial stability,avoiding the problem of the antibacterial effect causing by blending,and have great application prospects in the field of biomedicine.