Study On The Electrostatic Spinning Composite Membrane’s Preparation And Structural Properties Of Bacterial Cellulose Sulfate And Chitosan

Due to the difficulty of electronspinning chitosan (CS) and bacterial cellulose (BC) lonely, in this article, CS and BC were firstly modified. Chitosan was carboxymethylated with chloroacetic acid to prepare carboxymethyl chitosan (CMC). BC was sulfated with SO3/pyridine to obtain bacterial cellulose sulfate (BCS). To prepare biomimic membrane with nanofibers through electronspinning, a certain amount of PVA was used together with CMC and/or BCS. The membrane of chitosan-PVA, CMC-PVA and BCS-PVA were characterized and analyzed with the surface microscopic structure, wettability and hemocompatibiliy.(1) A certain amount of chitosan solution was dissolved in1%acetic acid and stirring until it dissolved firstly, and a certain amount of PVA water solution was added to chitosan solution to make the electronspinning solution. The electronspinning conditions were optimized. At the conditions of concentration of0.075g/ml,39.9kv voltage, distance20cm, solvent than V (d):V (H2O):V (PVA)=3:8:1, NaCl0.1g, the sample CS-6had a membrane with even distributed nanofibers, smooth surface and without beads. The contact angle of CS-6was43.7°. The contact angle increased to71.1°after CS-6was steam crosslinked with glutaraldehyde, indicating reduced hydrophilicity. Based on the results of platelet adhesion experiments, CS-6had good blood compatibility.(2) Chitosan was carboxymethylated to obtain CMC A certain amount of CMC completely dissolved in1%acetic acid solution, and then a certain amount of10%PVA solution was added to CMC solution to prepare the solution for electronspinning. The electronspinning conditions were optimized. At the conditions of CMC9.1g (0.152g/ml), solvent ratio of V (d):V (H20):V (PVA)=1:4:1,25kv voltage, distance23cm, NaCl0.2g, the sample CMCS-9had only nanofibers without beads. The contact angle of CMCS-9was28.3°, indicating the sample having good hydrophilicity. The contact angle value of CMCS increased to89.0°after crosslinked with steam glutaraldehyde, indicating the sample having hydrophobic surface. The results of platelet adhesion experiment showed that the sample with pure fibers had best blood compatibility.(3) BS was prepared through sulfation of BC with SO3/pyridine. A certain concentration of BS aqueous solution and8%PVA water solution were mixed together to prepare electronspinning solution. When the spinning conditions were sulfate bacterial cellulose6.5g,0.108g/ml, solvent ratio of V (H20):V(PVA)=2:1, distance23cm and25kv voltage, NaCl0.2g, the electronspun membrane had only fibers, without beads. The contact angle was28.3°. Through double nozzle electronspinning, ethyl cellulose and BS-PVA were electronspun together. When the spinning conditions were BS0.108g/mL, ethyl cellulose0.05g/mL, V (H2O):V (PVA)=2:1, distance23cm, double nozzle space4.5cm,25kv voltage, NaCl0.2g, the electronspun membrane had only fibers, with a contact angle of50.1°. The results of platelet adhesion experiment showed that the sample had good blood compatibility.