Reusable Zwitterionic Porous Organic Polymers for Bilirubin Removal in Serum

Herein, we report a straightforward strategy to construct reusable, hemocompatible, and highly efficient bilirubin adsorbents by installing zwitterionic modules into porous organic polymer (POP) for hemoperfusion application. Three types of zwitterions with different amounts are used to evaluate their impacts on the characteristics of POP, including carboxybetaine methacrylate (CB), sulfobetaine methacrylate (SB), and 2-methacryloyloxyethyl phosphorylcholine (MPC). Results show that zwitterion installation can improve the hemocompatibility, hydrophilicity, and bilirubin uptake of the POP. Among all zwitterionic POPs, POP-CB-40% performs the best in bilirubin adsorption test, and its bilirubin uptake capacity in 100% serum is ~ 46.5 times enhancement compared with the non-zwitterionic POP. This enhancement can be attributed to the improved hydrophilicity and protein resistance ability in biological solutions. More importantly, the reusability test shows that POP-CB-40% remains ~ 99% of bilirubin uptake capacity at fifth recycling in 100% serum. Findings in this work provide a guideline to design biocompatible and efficient POP-based bilirubin adsorbents for hemoperfusion therapy.