Polymyxin B immobilized nanofiber sponge for endotoxin adsorption

Abstract

Nanofiber sponge, which showed high porosity and excellent blood compatibility, was successfully prepared by electrospinning and freeze-drying technology. The APTT (activated partial thromboplastin time) and PT (prothrombin time) of human plasma with nanofiber sponge were a little longer than control groups, which revealed the nanofiber sponge has excellent blood compatibility. By activating the carboxyl groups on the fibers, PMB (polymyxin B) was successfully immobilized on the nanofiber sponge. The adsorption performance was researched in different solutions. The adsorption capacity in physiological saline solution was around 17,889 EU/mL and the adsorption equilibrium time was about 40 min. The adsorption behavior not only obeyed to second-order kinetic equation, but also was conformed to Langmuir model, which turned out to be chemical adsorption and monolayer adsorption. The endotoxin removal rate in BSA (bovine serum albumin) physiological saline solution was about 96.6%, and the BSA recovery rate was around 75.6%, which indicated the PMB immobilized nanofiber sponge adsorbed endotoxin selectively. The endotoxin removal rate of normal nanofiber sponge was about 17.3%, while it was around 99.6% when it comes to PMB immobilized-nanofiber sponge, which manifested PMB played an important role in endotoxin adsorption. The endotoxin removal rate in human plasma reached 90%, and the adsorption reached equilibrium within 60 min, which proved the PMB immobilized-nanofiber sponge would have great potential for applying in clinical blood purification.