Chitosan/cellulose acetate electrospun nanofibrous membrane with high efficiency in endotoxin adsorption

Electrostatic spinning technology can prepare nanofiber materials with high specific surface area and unique microstructure. Cellulose acetate (CA) has excellent membrane formation and processability, while chitosan (CS) is positively charged due to the abundance of amino groups and has certain biological activities. In this paper, CA/CS nanofiber membranes with different CS contents were prepared by solution blending and electrostatic spinning techniques and used in hemoperfusion (HP) for targeted removal of endotoxins. The CA/CS nanofibrous membranes were systematically characterized using infrared spectroscopy, scanning electron microscopy, etc., and the clearance ability of CA/CS nanofibrous membranes for endotoxin was tested under static and dynamic simulated HP conditions. The results showed that the addition of CS changed the structure of CA nanofibers, significantly increased the specific surface area of CA/CS nanofiber membrane, and provided more adsorption sites for the membrane material. The positive charge of CS interacted with the negatively charged endotoxin in the blood through electrostatic attraction, which enabled the CA/CS nanofiber membranes to adsorb endotoxin efficiently and exhibit higher endotoxin clearance ability. In the static adsorption experiment, when the CS content was 3.75%, the endotoxin adsorption and clearance rate could reach 580.0 ± 32.2 EU/g and 65.1 ± 3.6%, respectively. In the dynamic adsorption experiment, when the CS content was 2.50%, the CA/CS nanofiber membrane had a good effect on the adsorption of endotoxin. Meanwhile, CA/CS nanofiber membrane also has good blood compatibility. Therefore, the CA/CS nanofiber membrane is potentially valuable in blood purification.