Hydrogel Microencapsulation Enhances Cryopreservation of Red Blood Cells with Trehalose

Advanced cryopreservation engineering strategies: the critical step to utilize stem cell products

With the rapid development of stem cell-related therapies and regenerative medicine, the clinical application of stem cell products is on the rise. However, ensuring the effectiveness of these products after storage and transportation remains a challenge in the transformation to clinical trials. Cryopreservation technology allows for the long-term storage of cells while ensuring viability, making it a top priority for stem cell preservation. The field of cryopreservation-related engineering technologies is thriving, and this review provides an overview of the background and basic principles of cryopreservation. It then delves into the main bioengineering technologies and strategies used in cryopreservation, including photothermal and electromagnetic rewarming, microencapsulation, and synergetic ice inhibition. Finally, the current challenges and future prospects in the field of efficient cryopreservation of stem cells are summarized and discussed.

Integration of Trehalose Lipids with Dissociative Trehalose Enables Cryopreservation of Human RBCs

Cryopreservation of red blood cells (RBCs) is imperative for transfusion therapy, while cryoprotectants are essential to protect RBCs from cryoinjury under freezing temperatures. Trehalose has been considered as a biocompatible cryoprotectant that naturally accumulates in organisms to tolerate anhydrobiosis and cryobiosis. Herein, we report a feasible protocol that enables glycerol-free cryopreservation of human RBCs by integration of the synthesized trehalose lipids and dissociative trehalose through ice tuning and membrane stabilization. Typically, in comparison with sucrose monolaurate or trehalose only, trehalose monolaurate was able to protect cell membranes against freeze stress, achieving 96.9 ± 2.0% cryosurvival after incubation and cryopreservation of human RBCs with 0.8 M trehalose. Moreover, there were slight changes in cell morphology and cell functions. It was further confirmed by isothermal titration calorimetry and osmotic fragility tests that the moderate membrane-binding activity of trehalose lipids exerted cell stabilization for high cryosurvival. The aforementioned study is likely to provide an alternative way for glycerol-free cryopreservation of human RBCs and other types of cells.