Regenerated Cellulose Hydrogel for Green, Efficient, and Selective Heparin Extraction.

Heparin is a critical anticoagulant, yet its purification remains challenging. Most commercial adsorbents are derived from petroleum-based polymers, which may introduce microplastics into the human bloodstream during medical use, posing a potential health risk. Herein, we report a regenerated positively charged cellulose nanofibril (PCCNF)-based hydrogel as a green and efficient alternative for selective heparin extraction. With quaternary ammonium modification, PCCNFs capture ∼88% heparin within 1 min, which outperforms commercial Amberlite IRA-900. We then produce regenerated cationic cellulose (cCell) hydrogels through an ionic liquid (IL) dissolution and regeneration process from PCCNFs, and we demonstrate their high selectivity toward heparin even in the presence of protein contaminants and their excellent reusability over multiple cycles. Finally, the regenerated cCell hydrogels are fabricated into monodispersed spheres via electrospraying for column-based operations, and efficient heparin extraction is verified. This work highlights the potential of regenerated cellulose-based hydrogels as scalable, sustainable substitutes for conventional plastic adsorbents in the recovery of heparin and other polyelectrolytes.