Improving the Blood Compatibility and the Gas Permeability of Polyether Ether Ketone Hollow Fiber Membrane Used for Membrane Oxygenator via Grafting Hydrophilic Components

Abstract

As the core component of extracorporeal membrane oxygenation (ECMO) therapy for patients with severe cardiopulmonary failure, the structures and the properties of membrane oxygenator play a crucial role in determining both the efficiency of the gas exchange and the safety of the patients. Herein, with the aim of enhancing the blood compatibility, gas permeability, and durability of the membrane oxygenator, a porous polyether ether ketone hollow fiber membrane (PEEK-HFM) was prepared via a combination of melt spinning and thermally induced phase separation method. Subsequently, three different hydrophilic components including a nonionic polymer (poly(ethylene glycol), PEG), an ionic monomer (acrylic acid, AA), and a zwitterionic monomer (2-methacryloyloxyethyl phosphorylcholine, MPC) were introduced onto the PEEK-HFM surface by UV-induced grafting. The effects of different hydrophilic modifications on the surface characteristics (such as surface water wettability, surface potential, and porous morphologies) and the related properties (including mechanical performance, blood compatibility, and gas exchange permeability) were studied in detail. After grafting different hydrophilic components, not only the pore size of the corresponding PEEK-HFMs decreased compared to the unmodified PEEK-HFMs but also the surface roughness. Meanwhile, although the hydrophilic modifications resulted in the deterioration of the tensile strength of resulting PHFMs, it enhanced the blood compatibility of modified PEEK-HFMs. Moreover, among these modified membranes, the one grafted with MPC showed the best blood compatibility due to its more hydrophilic surface. Additionally, the modified membranes still maintained excellent gas permeability, ensuring the gas exchange performance between carbon dioxide and oxygen. Furthermore, a comprehensive comparison between the modified PEEK-HFMs and a commercial membrane oxygenator (poly(4-methyl-1-pentene), PMP) demonstrated that the modified PEEK-HFMs exhibited higher gas permeability, better blood compatibility, stronger gas exchange ability, and comparable tensile strength, indicating their potential as a high-efficiency option for membrane oxygenators.