Indoxyl sulfate (IS) has been reported to accelerate the progression of chronic kidney disease (CKD) and also increase the risk of cardiovascular disease by increasing the oxidative stress of CKD patients. Current haemodialysis facilities are designed for diffusive clearance and do not effectively clear protein-bound uremic toxins, such as indoxyl sulfate (IS). Thus, porous absorbent materials have been developed and used in wearable artificial kidney (WAK) devices to increase the protein-bound uraemic toxin clearance. However, the toxicity of a molecule is not necessarily determined by size alone. Chitosan (CS) has been used in water filtration systems since the 1990s to remove organic contaminates through interactions between amine groups and conjugated compounds, which could potentially absorb the IS molecules by interacting with its conjugated chemical structure. As proof of concept, we report on an electrospun polycaprolactone/chitosan (PCL/CS) fibrous absorbent for IS removal based on chemical structural interaction (Figure 1). This composite absorbent material has a high internal surface to volume ratio so as to greatly increase the interaction between the IS and chitosan. This PCL/CS absorbent material was fabricated by 2D-controlled close-range electrospinning. The fibrous nano-structure was characterized by a scanning electron microscopy (SEM). The IS molecule absorption of the PCL/CS fibrous absorbent was quantitatively evaluated. A single unit (20mm in length) of our PCL/CS absorbent achieved a 25% clearance of IS within an hour at 40mg/L in a single pass model. This novel nanocomposite absorbent may provide new ideas for the removal of metabolic toxins in a portable way.

Chitosan composed electrospun nanofibrous membrane for indoxyl sulfate sorption

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.