Dual-layered composite nanofiber membrane with Cu-BTC-modified electrospun nanofibers and biopolymeric nanofibers for the removal of uremic toxins and its application in hemodialysis

In order to prepare a kind of hemodialysis membrane with both adsorption and dialysis abilities, we prepared a novel dual-layer composite nanofiber membrane by combining two different kinds of composite electrospun nanofibers. One layer of the membrane contains specially prepared polydopamine/polyacrylonitrile (PDA/PAN) composite nanofibers modified by self-assembly of Cu-BTC on the surface of the nanofibers, which exhibit good adsorption capacity for urea. The second layer of the membrane contains biopolymers of chitosan/sericin (CS/SS) composite nanofibers, which show a good adsorption capacity for creatinine. The obtained dual-layer nanofiber membranes possess excellent blood compatibility. The maximum adsorption capacity of the dual-layer composite nanofiber membrane for creatinine is 100.50 mg/g, and the maximum adsorption capacity for urea can reach as high as 152.44 mg/g. In addition, a multi-layer flat-plate dialyzer was designed and manufactured for dialysis process. The prepared nanofiber membranes were used as a hemodialysis membrane for simulated dialysis tests. After 4 h of dialysis, the retention rate of bovine serum albumin (BSA) of the composite nanofiber membrane is 83.9%, the clearance rates on creatinine and urea are 82.3% and 92.8%, respectively. The prepared novel dual-layer membranes have the capacity to be utilized as a new adsorbent for hemodialysis applications.