Core–Shell Microfiber Encapsulation Enables Glycerol-Free Cryopreservation of RBCs with High Hematocrit

Highlights We developed a novel method for high-efficiency, nontoxic, glycerol-free, scalable cryopreservation of human red blood cells with a high hematocrit (> 40%). This method offered the potential for ultrafast and convenient applications by eliminating the need for permeable cryoprotectants, simplifying the washing steps, and reducing the washing time. This method achieved a high RBC recovery of up to 95%, and the RBCs post-cryopreserved maintained their morphology, mechanics, and functional properties.