Synthesis Of New Antibacterial Components And Construction Of Antibacterial Functional Surface

Bacterial infection has brought great threat to human health,more and more researchers pay attention to antibacterial materials in rescent years.Bacterial infection begins with the contact and adhesion of bacteria on the surface of materials,and accumulates and propagates continuously to form biofilms,which eventually leads to inflammation and main immune response.Science the bacterial adhesion and aggregation usually occur on the surface of materials,the construction of antibacterial surface is an effective means to solve biofilms formation.However,traditional antibacterial surfaces have certain shortcomings,which are mainly maifeststed in three aspects: the use of antimicrobial components can easily lead to bacterial resistance,the surface cannot effectively remove dead bacteria,biofilm and surface cannot be reused.In order to solve the above problems,this work mainly carried out the following tasks:1)In response to the problem of bacterial resistance,a novel antibacterial nanoparticle was synthesized by self-assembly of polyquaternary ammonium salt with polyacrylic acid(PAA)and these nanoparticles were immobilized on the surface of the TC4 to prepare an antibacterial coating(STS).The particle size of the synthesized nanoparticles is uniform,the size distribution is about 200-300 nm,the decrease of surface wettability and the appearance of new elements on the STS surface indicate that the nanoparticles are successfully modified on the surface.The results of antibacterial tests showed that the STS had high antibacterial properties against Escherichia coli and Staphylococcus aureus,the nanoparticles on the coating surface did not diffuse and had good anti-bacterial adhesion.Platelet adhesion and hemolysis test also demonstrated that the modified surface also has good hemocompatibility.2)We prepared soft substrates based on polydimethylsiloxane/carbon nanomaterials(PDMS@CNT)and polymethyl methacrylate(PMMA)was used as hard surface layers,the near infrared photoresponsive fold surface samples(PDMS/PMMA)were obtained by using the dynamic wrinkle structure of the surface to realize the desorption of bacteria and biofilm.The results demonstrate that the content of CNT affects the heating rate of the sample,the type of solvent affects PDMS/PMMA surface morphology.The surface wrinkle height of PDMS/PMMA can be controlled from 150 nm-1.2μm,and the wrinkle wavelength from 300 nm-1.2μm by changing the PMMA concentration or the rotational speed of the sample.Bacterial adhesion experiments showed that the PDMS/PMMA surface had excellent adhesion ability after repeated irradiation of near infrared light.3)An antibacterial monomer with near-infrared light response type and reusable releasable ROS was synthesized,and then the antibacterial monomer was immobilized on the PDMS/PMMA surface by UV grafting polymerization to create a near-infrared light responsive antibacterial wrinkle surface(AWS).Antimicrobial experiments show that antimicrobial monomers have excellent antibacterial properties and can AWS achieve the function of sterilization and desorption of dead bacteria in one step by combining with the adhesion ability of de-bacteria with wrinkle structure.