Application Research Of Functionalized Chitosan Bio-carbon Material And Composite Polyurethane Film

Bacterial infection and thrombosis are the main causes of catheter-related diseases.Adhesion of bacteria and platelets in the catheter can induce biofilm formation,which greatly increases the incidence of catheter-related diseases.Because the current research on catheter-related diseases is still in its infancy,many bacterial infection mechanisms and coagulation mechanisms are not fully understood.Therefore,prevention of catheter-related infections and catheter-related thrombosis is an urgent problem to be solved,and it is necessary to prepare a biofunctional material that has both antibacterial and antiplatelet adhesion.In this study,yeast cells were first hydrothermally carbonized to produce amphiphilic bio-carbon materials(ACPs).The surface of the synthesized ACPs is rich in functional groups such as carboxyl groups,and can be highly dispersed as a good carrier material in solvents of different polarities.Secondly,since chitosan(CS)surface contains a large number of amino groups,we intend to construct a chitosanized bio-carbon material(ACPs-CS)based on ACPs and CS by amide reaction.Functionalized chitosan biochar materials(ACPs-CS-Hep/ACPs-CS-PVS-Ag)were then prepared by grafting heparin(Hep)and anionic nanosilver particles(PVS-Ag)with amino groups enriched on the surface of ACPs-CS.We used scanning electron microscopy(SEM),laser particle size and zeta potential analysis,amphiphilic analysis and thermogravimetric analysis(DTG)to systematically study the morphology characterizationand functional groups of the above materials.The surface functional molecules of ACPs-CS-Hep and ACPs-CS-PVS-Ag were determined by toluidine blue method and ultraviolet spectrophotometer respectively,and then the anticoagulant activity and antibacterial activity of the materials were verified.The hemocompatibility and biocompatibility of the materials were systematically studied through hemolysis experiments and cytotoxicity experiments.The results of anticoagulation experiments showed that ACPs-CS-Hep still had excellent anticoagulant activity,which was mainly reflected in the abnormal blood coagulation process in blood coagulation experiments.The results of antibacterial experiments showed that ACPs-CS-PVS-Ag had high antibacterial activity against Gram-positive/negative bacteria,fungi and resistant bacteria,and the minimum inhibitory concentration was up to microgram level.The results of hemolysis test and cytotoxicity test showed that ACPs-CS-Hep and ACPs-CS-PVS-Ag were not toxic to normal human liver cells under active concentration conditions,and had good blood compatibility and biological phase under physiological conditions.Finally,the synthesized ACPs-CS-Hep and ACPs-CS-PVS-Ag were miscible with thermoplastic polyurethane material(TPU)in N,N-dimethylformamide(DMF)solvent to obtain uniform stability antibacterial and anticoagulant film by volatile solvent.We first studied the mechanical properties and contact angle of the prepared functionalized TPU film.The results showed that after mixing the above materials in TPU,not only the mechanical properties were maintained,but also the hydrophilicity of the TPU film was improved.The antibacterial and anticoagulant activities of the functionalized TPU film were then tested.The results of the antibacterial anticoagulation experiment showed that the functionalized TPU membrane exhibited the same antibacterial activity as the ACPs-CS-PVS-Ag particles compared with the blank TPU film.In addition,platelet adhesion rarely showed that ACPs-CS-Hep played a large role in antiplatelet adhesion in the TPU film.Therefore,the use of functionalized chitosan biochar materials for the preparation of functionalized TPU films as a pre-study for the prevention of catheter-related diseases is a good strategy and choice.