Fabrication of functional polyethersulfone (PES)-based materials for blood purification

Polyethersulfone (PES)-based materials have been increasingly applied in the area of blood purification because of their outstanding thermal, oxidative, and physical/chemical stability, excellent mechanical properties, mild sterilization conditions, and ease of processing. In addition, PES can easily form highly porous structures within the bulk by phase inversion between aqueous solutions and organic solvents. This pore-forming characteristic contributes to the application of PES-based materials for effective adsorption and separation in hemodialysis (HD), hemoperfusion (HP) and extracorporeal membrane oxygenation (ECMO). However, the intrinsic hydrophobic nature of PES, which leads to biofouling and relatively poor hemocompatibility, restricts its further practical use. This review outlines the concept of the heparin-like functionalization of PES, aiming to find an effective way to address the hemocompatibility issues. We discuss the fabrication strategy of functional PES-based materials and highlight the virtue of the proposed in situ crosslinking copolymerization method. We also review the fabricated multifunctional PES products, including membranes, microspheres and fibers, with not only anti-fouling, antibacterial, anticoagulant and antioxidant functions, but also stimulus-responsiveness under varied pH, salinity, anions, temperature, photoperiods and redox conditions. The integration of smart functions with novel structures, such as core-shell and bionic design enriches the variety of PES based materials and maximumly promoting the blood toxin adsorption and separation capacity. Thus, these materials are promising candidates for HD and HP applications in artificial kidneys, livers and lungs, aligning with current research developments. Finally, we summarize the perspectives and challenges of PES-based materials for blood purification and provide guidelines for the development of these materials, from functionalization and fabrication to biomedical engineering applications.