Electrospun fibers for toxin removal

Large surface area of electrospun fibers makes it a good candidate for removal of unwanted molecular substances from the environment. Given its proven biocompatibility in numerous studies as implantable scaffold and relative ease of functionalising, it may be modified for removal of toxins from body fluid.

Bilirubin is a well-known endogenous toxin which needs to be removed for patients with poor functioning liver. Several adsorbent materials have been reported for bilirubin removal. Wu et al (2016) tested the potential of electrospun porous polyether sulfone (PES) for this application given its high surface area. The membrane was found to exhibit a high adsorption capacity of 175.98 mg/g and rapid adsorption rate. Further studies are needed to determine its adsorption selectivity in the presence of other biomolecules.

For patients with kidney failure, dialysis is necessary to remove toxin from the body. Active compounds are sometimes required for targeted removal of toxins. In some cases, active particles or molecules for removal of toxin cannot be used directly in the body or bloodstream as they may be toxic to cells. In this case, electrospun fibers are a good candidate as carrier for them. For the purpose of removing creatinine from the blood in kidney failure patients, researchers have used electrospun fibers as carrier for zeolites, the active compound for removal of creatinine. Lu et al (2015) used polyacrylonitrile (PAN) for encapsulation of zeolites. Their study showed that the membrane containing zeolites was able to adsorbed more creatinine than free zeolites particles. Speed of adsorption was also fast with 91% removal of 2 µmolecular creatinine at 5 mins for 0.025g of zeolite powders. Takai et al (2016) used a blood-compatible polymer, poly(ethylene-co-vinyl alcohol) (EVOH) for encapsulation of zeolites by electrospinning. EVOH nanofibers containing zeolites were found to be capable of adsorbing creatinine. Biocompatibility tests were carried out using RAW264.7 macrophage cell lines on both EVOH nanofiber containing zeolites and zeolites particles. Their tests showed that cell viability of EVOH/zeolites nanofiber was at 90% but bare zeolite particles were toxic to the cells. This demonstrates that the nanofibers were effective in shielding zeolite particles from the cells while still capable of removing creatinine from the blood.

Creatinine adsorption capacity of the zeolite/EVOH nanofiber meshes as a role of immersion time at 37°C [Takai et al 2016. This work is licensed under a Creative Commons Attribution 3.0 Unported License.]