Hydrogel Microfiber Encapsulation Enhances Cryopreservation of Human Red Blood Cells with Low Concentrations of Glycerol

Abstract

Cryopreservation of red blood cells (RBCs) has been studied as a typical example of cryobiology methodology. To date, a mature and long-term cryopreservation process for RBCs has been developed, which has the weakness of complicated procedures due to high concentrations of glycerol (Gly). Therefore, it is still a research focus to find a new method for cryopreservation of RBCs to reduce the concentrations of cryoprotectants (CPAs). In this study, alginate hydrogels, which have been widely used in preservation research, were selected because of their advantages such as lower cost, cytocompatibility, and crosslinking occurring under mild conditions. With a variety of CPA solutions, the RBC recovery with the cryopreservation of RBCs and RBCladen hydrogel microfibers was compared in different situations. It was found that hydrogel microfiber encapsulation enhances cryopreservation of human RBCs with low concentrations of CPAs. And Gly can be removed by washing directly with a 0.9% sodium chloride solution. This study validated the feasibility of cryopreservation of RBC-laden hydrogel microfibers. It may provide a new and evolving direction for reducing the concentrations of CPAs used in the preservation of RBCs.

Nonionic and Water-Soluble Poly(d/l-serine) as a Promising Biomedical Polymer for Cryopreservation

“…So far, we have demonstrated that poly­( d / l -serine) is water-soluble, biodegradable, and non-cytotoxic, making it a desirable biomedical polymer and probably can be used as the PEG alternative with degradability and functional groups. Here, we took RBC cryopreservation ,,− as an example to illustrate the potential biomedical applications of poly­( d / l -serine). A series of recrystallization experiments were carried out with the “splat-cooling” assay , to investigate the IRI activity of poly­( d / l -serine) (Figures a and S8–S10).…”

“…Recently, the cryopreservation of blood has become an urgent need because of the sizable demand and the short survival time (42 days at most) without cryopreservation and in complex isotonic solutions. − According to previous reports, the extracellular ice formation (ice recrystallization) during the thawing process is one of the major reasons causing cell death. In order to solve this problem, a lot of synthetic materials such as glycopeptides, peptides, polymers, , hydrogel microfiber, and some other nano materials − with specific ice recrystallization inhibition (IRI) activity and a good cryoprotective effect have been reported. However, the toxicity and biodegradability of these synthetic materials remain to be investigated.…”

Hydrogel Microencapsulation Enhances Cryopreservation of Red Blood Cells with Trehalose

“…The mixed RBC hematocrit was ∼40%. The RBC–CPA hybrid solution flowed out from the concentric inner chamber of the tube-in-tube device (23 G, inlet 1) and the outer chamber (17 G, inlet 2) for 2% sodium alginate outflow . As the concentric droplets at the tip of the needle flowed out, they were broken up into microdroplets by the electric field generated from a high-voltage generator.…”

“…In 2017, Zhao et al first reported hydrogel microencapsulated porcine adipose-derived stem cells and successfully achieved low-concentration CPA vitrification. − In a later study, they successfully combined magnetic warming with hydrogel microencapsulation, achieving low-CPA vitrification cryopreservation of stem cells. − , Additionally, Tian et al developed an ultrafine hydrogel microfiber encapsulation system to successfully achieve low-concentration and low-toxicity vitrification . Cao et al used hydrogel microfiber encapsulation of RBCs and successfully enhanced the recovery of RBCs at a low concentration of glycerol . However, microencapsulation of RBCs has not been reported thus far.…”

One-Step Generation of Aqueous-Droplet-Filled Hydrogel Fibers as Organoid Carriers Using an All-in-Water Microfluidic System

“…Hydrogel fibers have emerged as promising scaffolds in materials science, cell biology, and tissue engineering for their large specific surface area, excellent biodegradability, and flexible mechanical properties. − Hydrogel fibers are widely used in transplant carriers, , drug delivery, and hydrogel sensors, , which are produced by coating, electrospinning, , bioprinting, − and microfluidics . In recent years, the microfluidic technique has been utilized as a versatile tool to fabricate the hydrogel fibers with various structures, compositions, and functions due to the flexibility of chip design and the accuracy of flow control .…”