Zwitterionization of common hemodialysis membranes: Assessment of different immobilized structure impact on hydrophilicity and biocompatibility of poly aryl ether sulfone (PAES)and cellulose triacetate (CTA)hemodialysis membranes

Hemodialysis (HD)membrane materials-blood hemocompatibility is considered as the most important reason for intra- and post hemodialysis complications. The incompatibility could result in different cascade activations due to the interactions between vital human serum proteins (HSPs)and HD membranes. This study aims to assess the interaction energy between common hemodialysis polymer structures in the zwitterionized state and HSPs using molecular dynamics (MD)simulation to offer a framework for understanding the dominant interactions as a reference for HD material development. To perform zwitterionization, a feasible mussel-inspired methodology was used. Poly aryl ether sulfone (PAES)and cellulose triacetate (CTA)were chosen for the base membrane models and carboxybetaine methacrylate (CBMA), sulfobetaine methacrylate (SBMA), and phosphobetaine methacrylate (PBMA)were picked as common zwitterionic structures (ZWs)for surface modification. Human serum albumin (HSA), fibrinogen (FB), and transferrin (TRF)were selected as the models of HSPs. Polydopamine (PDA)was used for the binding structure. The binding energy of the membrane models and selected proteins, as well as the hydrophilicity of the membrane models, was assessed. Hydrophilicity assessment of the membrane models suggests that PBMA creates more tendency to water molecules when the modifying layer is located on both CTA- and PAES-based membrane models. The results suggest that the hemocompatibility of the membranes does not directly correlate with the hydrophilicity of the polymeric structures. While each protein creates a specific trend when interacting with membrane models with different base polymers and modifying layers, natural biomolecules such as PDA or carboxybetaine structures are suggested to eliminate FB's interactions. For biocompatibility enhancement, as well as hydrophilicity enhancement, sulfo- and phosphobetaine-containing coatings could be used.