Hydrogel Microencapsulation Enhances Cryopreservation of Red Blood Cells with Trehalose

Cryopreservation of red blood cells (RBCs) plays a vitalrole in preserving rare blood and serologic testing, which is essentialfor clinical transfusion medicine. The main difficulties of the currentcryopreservation technique are the high glycerol concentration and thetedious deglycerolization procedure after thawing. In this study, weexplored a microencapsulation method for cryopreservation. RBC-hydrogel microcapsules with a diameter of approximately 2.184 +/- 0.061 mm were generated by an electrostatic spraying device. Then,0.7 M trehalose was used as a cryoprotective agent (CPA), andmicrocapsules were adhered to a stainless steel grid for liquid nitrogenfreezing. The results show that compared with the RBCs frozen bycryovials, the recovery of RBCs after microencapsulation issignificantly improved, up to a maximum of more than 85%.Additionally, the washing process can be completed using only 0.9% NaCl. After washing, the RBCs maintained their morphologyand adenosine 5 '-triphosphate (ATP) levels and met clinical transfusion standards. The microencapsulation method provides apromising, referenceable, and more practical strategy for future clinical transfusion medicine.