This content will become publicly available on January 1, 2025
- Award ID(s):
- 1827521
- NSF-PAR ID:
- 10478726
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Acta Astronautica
- Volume:
- 214
- Issue:
- C
- ISSN:
- 0094-5765
- Page Range / eLocation ID:
- 64 to 71
- Subject(s) / Keyword(s):
- Parabolic flight freeze-dried RBCs 0 g fluid dynamics transfusion anhydrobiosis
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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One of the most common life-saving medical procedures is a red blood cell (RBC) transfusion. Unfortunately, RBCs for transfusion have a limited shelf life after donation due to detrimental storage effects on their morphological and biochemical properties. Inspired by nature, a biomimetics approach was developed to preserve RBCs for long-term storage using compounds found in animals with a natural propensity to survive in a frozen or desiccated state for decades. Trehalose was employed as a cryoprotective agent and added to the extracellular freezing solution of porcine RBCs. Slow cooling (-1 C min-1) resulted in almost complete hemolysis (1 ± 1 % RBC recovery), and rapid cooling rates had to be used to achieve satisfactory cryopreservation outcomes. After rapid cooling, the highest percentage of RBC recovery was obtained by plunging in liquid nitrogen and thawing at 55 C, using a cryopreservation solution containing 300 mM trehalose. Under these conditions, 88 ± 8 % of processed RBCs were recovered and retained hemoglobin (14 ± 2 % hemolysis). Hemoglobin’s oxygen-binding properties of cryopreserved RBCs were not significantly different to unfrozen controls and was allosterically regulated by 2,3-bisphosphoglycerate. These data indicate the feasibility of using trehalose instead of glycerol as a cryoprotective compound for RBCs. In contrast to glycerol, trehalose-preserved RBCs can potentially be transfused without time-consuming washing steps, which significantly facilitates the usage of cryopreserved transfusible units in trauma situations when time is of the essence.more » « less
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Sulfide breakdown during subduction releases oxidizing fluids that transport chalcophile and siderophile elements (CSE) such as Ni ,Co, and As. These fluids are reincorporated into high-pressure rocks such as eclogites during exhumation and rehydration along the slab-mantle interface. Evidence for these rehydration reactions takes the form of large sulfide (pyrite, pyrrhotite, chalcopyrite) grains (up to 5 mm) associated with hydrous Fe3+-bearing minerals. Here we present results of trace element determination by LA-ICP-MS coupled with mass balance calculations for sulfide-silicate reactions in rehydrated eclogites from the Mariánské Lázně Complex and Moldanubian Zone, Bohemian Massif, Czech Republic. One key texture observed in these rocks is the breakdown of garnet + omphacite in the presence of fluid to produce hornblende + diopside + plagioclase + pyrite. This rehydration reaction involves the oxidation of Fe2+ in garnet to Fe3+ in hornblende. In order to oxidize the iron from the garnet, we propose that sulfate is brought into the rock by an infiltrating fluid, where it is reduced to form pyrite, consistent with the observed textures. Trace element analyses reveal the Co distribution within rehydrated eclogite: Co is measurable in garnet (~50 μg/g), omphacite (~26 μg/g), hornblende (~80 μg/g), and pyrite (~5000 μg/g). Mass balance calculations suggest that of the total amount of Co present in the rehydration products, only ~35 % can be supplied by the breakdown of garnet and omphacite, leaving ~65 % of the Co to be supplied by another source. Average concentrations of Ni are: in garnet (1–4 μg/g), omphacite (~57 μg/g), hornblende (~90 μg/g), and pyrite (~2500 μg/g). Mass balance calculations suggest that of the total amount of Ni present in the rehydration products, ~70 % comes from the breakdown of garnet + omphacite, with the other 30 % supplied external to this reaction. Arsenic is not present in the silicate minerals, but is in the 10s of μg/g range in pyrite, and must be supplied externally to the rock, likely from a fluid. We conclude that the fluids released from subducting slabs carry sulfate and CSEs, which infiltrate the slab-mantle interface and eventually make their way into the sub-arc mantle, where they can be incorporated into the arc magmatic system.more » « less
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Abstract Dryophytes chrysoscelis (formerlyHyla chrysoscelis , Cope’s gray treefrog) is a freeze‐tolerant anuran that accumulates glycerol and urea during cold acclimation and freezing. It is hypothesized that glycerol and urea function as cryoprotectants by minimizing osmotically induced cell damage during freezing and thawing, thereby improving the postfreeze viability of red blood cells (RBCs) when frozen in medium containing those solutes. To test this, erythrocytes were obtained from warm (22°C) and cold‐acclimated (4°C) frogs and suspended in 280 mOsM phosphate‐buffered saline (PBS). RBCs were frozen in 280 mOsM, isosmotic/isotonic, PBS, or in PBS made hyperosmotic by addition of 150 mM solutes. Postfreeze viability was determined with a hemolysis assay. Postfreeze viability of cells from warm‐acclimated frogs improved from 18.9 ± 1.3% in PBS to 47.4 ± 5.2% in PBS with urea (p < 0.01). The addition of other solutes (glycerol, glucose, NaCl, or sorbitol) had no effect. RBCs from cold‐acclimated frogs had 45.8 ± 3.4% viability when frozen in 280 mOsM PBS, and this improved to 71.6 ± 8.9% or 71.9 ± 1.6%, respectively, when frozen with glycerol (p < 0.01) or urea (p < 0.001). The viability of RBCs from cold‐acclimated frogs was not different between unfrozen cells 86.7–88.4%) and those frozen with glycerol (71.6 ± 8.9%,p > 0.05) or with urea (71.9 ± 1.6%,p > 0.05). These data suggest that (a) cold acclimation induces cellular changes in RBCs that result in improved postfreeze viability, and (b) glycerol and urea are part of a complex cryoprotectant system inD. chrysoscelis. -
Transfusion of red blood cells (RBCs) is one of the most valuable and widespread treatments in modern medicine. Lifesaving RBC transfusions are facilitated by the cold storage of RBC units in blood banks worldwide. Currently, RBC storage and subsequent transfusion practices are performed using simplistic workflows. More specifically, most blood banks follow the “first-in-first-out” principle to avoid wastage, whereas most healthcare providers prefer the “last-in-first-out” approach simply favoring chronologically younger RBCs. Neither approach addresses recent advances through -omics showing that stored RBC quality is highly variable depending on donor-, time-, and processing-specific factors. Thus, it is time to rethink our workflows in transfusion medicine taking advantage of novel technologies to perform RBC quality assessment. We imagine a future where lab-on-a-chip technologies utilize novel predictive markers of RBC quality identified by -omics and machine learning to usher in a new era of safer and precise transfusion medicine.
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