Narrative review of strategies for blood product shelf‐life extension

Abbreviations

1:1:1

ratio of red blood cells:plasma:platelets

2,3‐DPG

2,3‐diphosphoglycerate

ACP‐215

Automated Cell Processor (Haemonetics)

AS

additive solution

AS‐1

Additive solution 1

AS‐3

Additive solution 3

AS‐5

additive solution 5

AS‐7

additive solution 7

ATP

adenosine triphosphate

COBE 2991

Automated Cell Washer (Terumo BCT)

CP2D

citrate–phosphate–double dextrose

CPD

citrate‐phosphate‐dextrose

CPDA‐1

citrate–phosphate–dextrose–adenine

CPP

cryopreserved platelets

CPRBC

cryopreserved red blood cells

CSP

cold‐stored platelets

DAS

deoxygenation and anaerobic storage

DMSO

dimethyl sulfoxide

EUA

emergency use authorization

FDA

U.S. Food and Drug Administration

FDP

freeze‐dried plasma

FFP

fresh frozen plasma

LSCO

Large‐Scale Combat Operations

LTOWB

low titer group O whole blood

MTF

medical treatment facility

PAS

platelet additive solutions

PDHA

platelet‐derived hemostatic agent

RBC

red blood cell

RCT

randomized controlled trial

RT

room temperature

SD

spray‐dried

TEG

thromboelastography

WB

whole blood

1. INTRODUCTION

Over 90% of potentially survivable United States (U.S.) battlefield fatalities are associated with severe hemorrhage, underscoring the importance of early prehospital blood transfusion to improve survival outcomes. Future near‐peer conflicts, such as Large‐Scale Combat Operations (LSCO), will introduce new challenges, including increased severity of injury patterns, delayed evacuations, and limited resupply of blood products. In such environments, finding innovative ways to prolong the shelf‐life of blood products is critical to ensuring the distribution of an adequate blood supply across operational theaters. This narrative review focuses on current and future methods to extend the shelf‐life of blood products. Many of the highlighted blood products are still in the development pipeline pending regulatory approval and may help support future blood banking constraints or augment whole blood use during times of surge.

2. BACKGROUND

Massive hemorrhage remains the leading cause of potentially preventable death in trauma patients in both civilian and military sectors. ¹ , ² These deaths often occur within 1 h due to exsanguination, coagulopathy, and shock. ¹ , ³ , ⁴ Restoring blood volume, neutralizing coagulopathy, and re‐establishing oxygen and hemostatic function within the first few minutes are crucial to preventing mortality. ⁵ Thus, trauma resuscitation guidelines emphasize early whole blood or component therapies targeting a 1:1:1 ratio of red blood cells (RBCs), plasma, and platelets. ⁶ , ⁷ Around the world, military and civilian institutions are developing Walking Blood Bank programs to facilitate urgent resuscitation efforts in resource‐constrained environments. ⁸ While observational evidence supports the association of low titer group O whole blood (LTOWB) with improved early mortality, logistical benefits, and reduced product utilization versus component therapy, ongoing randomized controlled trials, such as the Low‐Titer Group O Whole Blood or Products (TROOP) Trial, are needed to solidify its superiority. ⁹ , ¹⁰ Nevertheless, whole blood has limited availability, thus requiring additional blood products during times of constraint or surge.

3. MASS CASUALTY EVENTS AND BLOOD SHORTAGES

Future LSCO are expected to have increased rates and severity of injuries, straining blood product inventories. ¹¹ It is anticipated that inventory, resupply, and operational mobility will be challenged due to a highly mobile battlefield, lack of air superiority, and interruption of communications, with modern estimates of anticipated blood requirements rising to 10,000 units per month. ¹² , ¹³ , ¹⁴ Civilian health systems have also had challenges maintaining blood inventories during mass casualty events, exemplified by poor donor turnout resulting in shortages during the COVID‐19 pandemic. ¹⁵ The relatively short shelf‐life of most blood products adds complexity to maintaining adequate blood inventories, ¹⁶ and storage results in physiological reductions in function, often referred to as ‘storage lesions’. ¹⁷ , ¹⁸ Maintaining blood inventories during LSCO or mass casualty events will require leveraging all existing blood products through advancements that improve shelf‐life. ¹⁹ , ²⁰ Here, we review the current methodologies for improving the shelf‐life and efficacy of blood products, including anticoagulants, additives, deoxygenation/anaerobic storage, cryopreservation, and lyophilization of various blood components. Table 1 summarizes the major blood product shelf‐life extension strategies discussed in this review, highlighting their mechanisms and potential advantages in disaster settings (Table 1).

TABLE 1.

General strategies for improving storage and utilization of blood products.

Strategy	Description	Potential benefit in disaster setting	Key references
Ratio‐based rescue of CPD/CP2D‐stored WB with fresh WB supplementation	In‐vitro functionality of 35‐day‐old WB stored with anticoagulants of CPD and CP2D can be rescued with 1:4 or 1:5 of fresh WB	Potential to extend WB storage beyond 21‐day limitation and to 35 days. Would require in‐vivo validation if pursued	Meledeo, et al., Trasnfusion, 2019. Page 1549‐1559 26
Utilizing AS‐7 additive solution for RBC cold storage	Pushes cold‐storage duration to 56 days (vs. 42 days) with successful autologous 24‐h post‐transfusion recovery after 56 days of storage (<1% overall hemolysis, >75% RBC recovery)	Extends RBC storage to 56 days (vs. 42 days), potentially reducing resupply frequency, increasing local supply, and enhancing disaster preparedness	Cancelas, et al., Transfusion, 2015. p. 491–8 29
Using AS‐7 additive solution to allow for room‐temperature holding before processing	AS‐7 permitted RBC units to remain viable for up to 42 days of cold‐storage following an extended post‐draw, room temperature WB hold in CPD of 18–24 h, while still supporting successful autologous transfusions to healthy recipients	Enables up to 18 h of strategic WB holding before component processing and may confer logistical advantages such as improved inventory management, extended transport windows without expiration, and blood collection outside high‐risk areas.	Dumont, L. J., et al., Transfusion, 2015. p. 485–490 33
Deoxygenation and anearobic storage of RBCs	Removing oxygen content of RBC units before storage and maintaining these anearobic conditions during cold‐storage	Hypoxic storage pushes storage beyond 42 days, potentially +2 weeks with improved post‐transfusion recovery. Initially requiring inert gasses and specialized anearobic chambers, but new technology, such as Hemanext ONE bags, would eliminate this requirement. Increases local RBC unit supply, with possible increased post‐transfusion RBC recovery compared to aerobic storage.	Yoshida, T., et al., Vox Sang, 2007. p. 22–31 60 D'Alessandro, A., et al., Transfusion, 2020. p. 786–798 66 Rabcuka, J., et al., Blood Adv, 2022. p. 5415–5428 64 Dumont, L. J., et al., Transfusion, 2016. p. 392–403 63
Cryopreservation of RBCs	Adding glycerol as a cryoprotectant to freshly obtained whole blood to allow freezing blood units for up to 10 years of storage in ≥ −65°C conditions	Allows for strategic stockpiling of RBC units and their utilization as a contingency reserve blood supply. Preparation still neccesitates a thawing, deglycerolization, and resuspension process prior to use.	Cap, et al., Military Medicine, 2018. p. 52–54 67 Chang et al., Blood Transfusion, 2017. p. 341–347 68
Cold‐stored platelets	Adding specific platelet additive solutions to platelets to allow for cold storage (1°C to 6°C) for up to 14 days.	Significantly improves storage duration and local supply of platelets when compared to room‐temperature liquid storage of platelets, which is 5–7 days. CHIPS trial recently completed, assessing noninferiority of cold‐stored platelets with max storage duration of 21 days vs. room temperature‐stored platelets. Cold‐stored platelet phenotype also suggests a potential benefit during hemorrhage.	Strandenes, G., et al., Anesthesiology, 2020. p. 1173–1183 55 Zantek, N.D., et al., Clin Trials, 2023. p. 36–46 56 Apelseth, T.O., et al., Science Series, 2017. p. 488–495 57
Cyropreserved platelets	Adding DMSO as a cryoprotectant to allow −80°C storage for up to 2 years and thawing of approximately 10 min with a post‐thaw shelf‐life of within 4 to 6 h. Upcoming Cellphire product CLPH‐511 offers extended storage of 5 years in ≤ −65°C	Allows for strategic stockpiling and sustained platelet availability but contingent on intact and reliable cold‐chain infrastructure with point‐of‐care thawing. Significant storage duration benefit over standard liquid stored platelets with limited shelf life of 5–7 days. Frozen activated phenotype of CPP suggested to be beneficial in trauma patients. Successfully implemented in prior military blood banks. CLIP‐II CLIPNZ‐II, and CRYPTIC trials completed comparing efficiency of CPP to liquid stored platelets	Valeri, C.R. et al., Transfusion, 2005. p. 1890–8 81 Cohn, C.S., et al., Vox Sang, 2017. p. 684–688 83 Cid, J., et al., Transfusion, 2016. p. 580–6 84 Noorman, F., et al., PLoS One, 2016. p. e0168401 87 Reade, M.C., et al., BMJ Open, 2022. p. e068933 82 Whitman, G. et al., JTCVS Open. 2022 91
Freeze‐dried plasma	Sublimated‐based technique involving the removal of water and solvents from blood products. Allows for increased stability at room temperature and increasing the shelf‐life of its lyophilized product. Easily reconsistuted in minutes. OctoplaLG recently granted emergency use authorization	Removes reliance on refrigerated or temperature‐controlled supply chain. Allows for stockpiling of a stable form of blood product and feasible packaging/transport. Utilized by the French military, the German Red Cross, South Africa, the Israeli Defense Force, and the US with an EUA	Zaza, M. et al., Damage Control Resuscitation, 2019. p. 145–62 95 Pusateri, A. E., et al., Anesthesiology, 2022. p. 327–335 105 Shlaifer, A., et al., J Trauma Acute Care Surg, 2017. p. 675–682 102 Cuenca, et al., J Spec Oper Med, 2020. p. 43–45 103 Benov, A., et al., Injury, 2016. p. 993–1000 101
Sray dried plasma	Evaporation‐based, powder generation process that produces an accumulated dry powder state of plasma that can be easily reconsistuted. Similar to freeze‐dried plasma but not interchangeable; has been shown to be equally efficacious in swine polytrauma hemorrhage models. FrontlineODP, produced by Velico Medical, allows a shelf‐life of up to 2 years at room temperature and short reconstitution times	Similar to freeze‐dried plasma, dit does not rely on a refrigerated or temperature‐controlled supply chain. Allows strategic stockpiling with feasible packaging and transport. Easily reconstituted within minutes.	Zaza, M. et al., Damage Control Resuscitation, 2019. p. 145–62 95 Shuja, F., et al., J Trauma, 2011. p. 664–71 112 Pusateri, A.E., et al., Transfusion, 2016. Suppl 1 p. S16‐23 99
Lyophilized platelets	Dehydration of platelets and the addition of stabilizing molecules, such as trehalose, to allow room‐temperature storage and easy reconstitution. Still under development and clinical trials. Cellphire's Thrombosomes have a 3‐year shelf‐life at room temperature	Substantially increases conventional platelet shelf‐life of 3–5 days and would allow for strategic stockpiling with feasible packaging and transport. Easily reconstituted within minutes. Would not rely on a refrigerated or temperature‐controlled supply chain	Bynum, J.A., et al., Transfusion, 2019. p. 1490–1498 118 Kuhn, B.J., et al., J Thromb Haemost, 2024. p. 686–699 119 Ohanian, M., et al., Am J Hematol, 2022. p. 256–266 120 Goodrich, R.P., et al., Proc Natl Acad Sci USA, 1992. p. 967–7 122
Lyophilized RBCSs	Inducing transient pore formation on RBC membranes to facilitate trehalose loading and allow for lyophilization of RBCs, and increase recovery of viable RBCs	Still under development using novel techniques such as soponification. Potential to strategically store and stockpile RBCs in room temperature conditions, beyond conventional refrigerated shelf‐life durations. Would not rely on a refrigerated or temperature‐controlled supply chain. Feasible packaging and transport	Janis, B.R., et al., Cryobiology, 2021. p. 73–79 129

4. ANTICOAGULANTS

4.1. Anticoagulants in whole blood

The primary challenge in maintaining a supply of blood is its inherent ability to clot ex vivo, prompting the development of anticoagulants to temporarily inhibit this process. Citrate is the primary component of anticoagulant solutions for transfusable blood, serving as a safe, reversible calcium chelator to inhibit the calcium‐dependent coagulation cascade. ²¹ Human blood transfusion with citrate began in 1914 but was standardized by Richard Lewisohn's work in 1915, which established an optimal dosing regimen of sodium citrate and confirmed its biocompatibility in both canine and human subjects; a follow‐on publication reported 22 successful clinical transfusions. ²² His work enabled widespread, reproducible, large‐volume blood transfusions. Building on this foundation, in 1918, U.S. Army physician Oswald Hope Robertson was credited with developing the “world's first blood bank.” ²³ Using the “Robertson Blood Jar,” a single‐operator blood collection apparatus prefilled with 3.8% citrate preservative for the collection of universal donor blood, units could be stored for 10 to 14 days on average before transfusion ²⁴ and transported to forward casualty clearing stations for critical transfusions. ²²

Modern anticoagulant solutions are still primarily reliant on citrate but also incorporate nutrients and buffers such as dextrose and phosphate to preserve cellular function. Table 2 provides a comparative overview of commonly used anticoagulant and additive solutions, including their approved storage durations, key features, benefits, and selected challenges relevant to blood product storage (Table 2). WB is currently stored in citrate–phosphate‐dextrose (CPD), citrate–phosphate‐double dextrose (CP2D), and citrate–phosphate‐dextrose‐adenine (CPDA‐1). CPD and CP2D are permitted to be stored at 4°C for up to 21 days, while CPDA‐1 allows for 35 days. ¹⁶ , ²⁵ , ²⁶ , ²⁷ , ²⁸ Results from a comparative in vitro analysis of WB stored in CPD, CP2D, or CPDA‐1 for 35 days demonstrated no significant declines in mean platelet volume, hematocrit, or hemoglobin by day 35, although there were significant decreases in platelet count, coagulation function, and platelet aggregation in CPD and CP2D, with higher levels of lactate observed in CP2D by day 14. ²⁶ Interestingly, the decline in function of older or expired WB was mitigated in a simulated massive transfusion by mixing fresh blood with old at ratios of 1:4 or 1:5. ²⁶ This serves as a proof‐of‐concept for extended CPD‐/CP2D‐stored WB in resource‐limited environments, especially in concert with a fresh unit from a walking blood bank.

TABLE 2.

Anticoagulants and additive solutions.

Solution type	Solution name	Storage duration	Key features	Benefits	Challenges	Key references
WB anticoagulants	Citrate‐phosphate‐dextrose (CPD)	21‐Days at 4°C	Formulation developed in the late 1950's to better support RBC viability during storage	The development of CPD improved upon the prior state‐of‐the‐art solution, Acid‐Citrate‐Dextrose (ACD)	During massive transfusions, the citrate may contribute to acute hypocalcemia, impaired clotting, and arrhythmias	Meledeo, et al., Transfusion, 2019. p. 1549‐1559 26
	Citrate‐phosphate‐double dextrose (CP2D)	21‐Days at 4°C	Formulation includes: Higher concentrations of dextrose and thus higher osmolarity than CPD intended to support RBCs	Developed to better support RBC metabolism and viability	Platelet concentrates from CP2D packs demonstrate reduced in vitro function after 5 days of storage	Moroff, G., et al., Transfusion, 1983. p. 484‐9 144
	Citrate‐phosphate‐dextrose‐adenine (CPDA‐1)	35‐Days at 4°C	Formulation includes: Adenine—to help support RBC metabolism	CPD supplemented with adenine (CPDA‐1) was in use, increasing the available storage time of WB and RBCs to 35 days. Extensions in shelf‐life were attributed to adenine's contribution to the increased synthesis of adenosine triphosphate	Storage lesion still occurs, and hypocalcemia remains a concern during massive transfusions	Rock, G., et al., Transfusion, 1998. p. 242‐6 145
RBC additive solutions	AS‐1 (Adsol)	42‐Days maintained at 1–6°C	Formulation includes: Adenine—to help support RBC Metabolism	AS‐1 demonstrates: Increased shelf‐life (42 days) compared to CPDA‐1's 35 days.	AS‐1 is a first‐generation additive solution that does not preserve RBC metabolism as well as future iterations	Tran, L.N.T., et al., Biomolecules, 2024. p. 14 (7) 146
			Dextrose—source of energy	Less hemolysis and membrane changes compared to CPDA‐1 and SAGM over 42 days	One report of that AS‐1 supernatant may prime polymorphonuclear neutrophils (PMN) on day 42	Sparrow, R.L., et al., Blood Transfus, 2012. Suppl 2 p. s7‐11 147
			Mannitol—source of energy and cell membrane stabilizer/osmotic agent
	As‐3 (Nutricel)	42‐Days maintained at 1–6°C	Formulation includes: Adenine—to help support RBC Metabolism	AS‐3 demonstrates: Normal RBC function early in storage <14 days; however, metabolic changes increase, and the storage lesion becomes more pronounced after day 14, likely due to the solutions' lower pH	AS‐3 demonstrates impaired metabolic function, loss of cell viability, accumulation of amino acids, and decreased 2,3‐DPG after 14 days of storage	D'Amici, G.M., et al., Blood Transfus, 2012. Suppl 2 p. s46‐54 148
			Dextrose—source of energy
			Citrate—anticoagulant
			Sodium chloride—maintains osmotic pressure
			Sodium Phosphate—helps with buffering to maintain pH
			Solution pH (~5.8)
	AS‐5 (E‐Sol)	42‐Days maintained at 1–6°C	Formulation includes: Adenine—to help support RBC Metabolism	AS‐5 demonstrates: Lower hemolysis and microparticle formation	AS‐5 demonstrates an accumulation of Pro‐inflammatory lipids in the supernatant towards the end of storage	Radwanski, K., et al., Vox Sang, 2014. p. 322‐9 149
			Dextrose—source of energy	Higher levels of ATP and 2,3‐DPG in the later stages of storage duration	PMN priming activity and higher potassium levels when compared to AS‐1	D'Alessandro, A., et al., Vox Sang, 2015. p. 131‐40 150
			Mannitol—source of energy and cell membrane stabilizer/osmotic agent
			Sodium chloride—maintains osmotic pressure
	AS‐7 (SOLX)	42‐Days maintained at 1–6°C	Formulation includes: Adenine—to help support RBC Metabolism	AS‐7 demonstrates: Reduced hemolysis, less microparticle formation, improved ATP and 2,3‐DPG preservation, and increased in vivo recovery	Concern exists for adenine and/or mannitol toxicity for transfused neonates or during massive transfusion protocols	Cancelas, J.A., et al., Transfusion, 2015. p. 491‐8 29
			Glucose—source of energy	In‐vitro studies suggest the possibility of extending storage with AS‐7 to 56 days; however, this duration is not FDA‐approved		D'Alessandro, A., et al., Transfusion, 2015. p. 2955‐66 32
			Mannitol—source of energy and cell membrane stabilizer/osmotic agent			Jain, R. et al., Transfus Apher Sci, 2001. p. 111‐5 151
			Phosphate—helps with buffering to maintain pH
Platelet additive solutions	PAS‐C (Intersol)	RT 5‐7 Days	Formulation includes: Sodium Citrate—to prevent clotting	No benefits were observed for cold‐stored platelets stored in Intersol when compared to Isoplate	Each additive solution is tied to the perceptive apheresis platform (Amicus into InterSol)	Reddoch‐Cardenas, K.M., et al., Transfusion, 2018. p. 1682‐1688 54
		4°C 14 Days	Sodium Phosphate—to buffer	More microaggregates were observed during storage, with an associated decrease in platelet count
			Sodium Acetate—to support oxidative phosphorylation
	PAS‐F (Isoplate)	RT 5–7 Days	Formulation includes: Sodium Phosphate—to buffer	Cold‐stored platelets demonstrated better: 1. Adhesion to collagen under flow and 2. Clot strength compared to Amicus‐collect apheresis platelets in Intersol	Each additive solution is tied to the perceptive apheresis platform (Trima into Isoplate)	Thomas, K.A., et al., Transfusion, 2023. Suppl 3. p. S146‐s158 152
		4°C 14 Days	Sodium Acetate—to support oxidative phosphorylation
			Potassium and Magnesium—to preserve platelet quality and prevent activation

5. ADDITIVE SOLUTIONS

5.1. Additives in packed red blood cells

Additive solutions (AS) serve as nutrients for packed RBCs during storage at 1–6°C. ²⁹ AS maintain the levels of 2,3‐diphosphoglycerate (2,3‐DPG) in RBCs, which are critical for optimal hemoglobin‐oxygen affinity in post‐transfusion peripheral tissue oxygenation. ³⁰ AS also maintain intracellular adenosine triphosphate (ATP) levels integral to RBC morphology, post‐transfusion recovery, and survival. ³⁰ There are currently four FDA‐approved RBC AS: AS‐1 (Adsol®, Fenwal Inc.), AS‐3 (Nutricel™, Cutter Biological), AS‐5 (Optisol™, Terumo Blood and Cell Technologies), and AS‐7 (The SOLX™ System, Hemerus Medical), all of which currently allow for a 42‐day shelf‐life. ¹⁶

AS‐7 is an alkaline solution designed to support RBC metabolism, reduce the storage lesion, and provide buffering capacity. ²⁹ , ³¹ , ³² While AS‐7 is FDA‐approved for 42‐day storage, Cancelas et al. discovered that 82% ± 3% of 56‐day AS‐7 stored RBCs remained viable at 24 h post‐transfusion during autologous in vivo studies, aligning with FDA guidelines that require at least 75% RBC viability with <1% overall hemolysis. ²⁹ Dumont et al. also demonstrated AS‐7's preservation of RBC ATP maintenance in CPD WB over 56 days when initially held for up to 18 h at room temperature (20–24°C) prior to RBC processing and refrigeration. ³³ In the 42‐day storage arm, all 27 human recipients in the in vivo post‐transfusion arm also met FDA criteria. ³³ The development of AS that allows for delaying WB processing while still permitting up to 42 days of cold storage is advantageous, as it operationally accommodates improved inventory management, extended transport windows, and blood collection outside of high‐risk areas.

5.2. Rejuvenation of red blood cells

RBC rejuvenation is an FDA‐approved process in which aged RBCs are briefly incubated in a solution (such as pyruvate, inosine, phosphate, and adenine) to restore the generation of 2,3‐DPG and ATP, improving oxygen unloading capability and reducing RBC storage lesions. ³⁴ , ³⁵ Decades of studies have been conducted, with the first clinical report of the administration of rejuvenated RBCs to humans in 1972. ³⁶ , ³⁷ Cardiac surgery patients receiving rejuvenated, frozen, deglycerolized cells (stored for 1 year) exhibited higher 2,3‐DPG levels and improved oxygen utilization and cardiac index compared to patients receiving stored allogeneic or autologous RBCs. ³⁸ Interestingly, the rejuvenation process also reduced potassium levels in stored blood, ³⁷ potentially explained by the corresponding reduction in hemolysis and maintenance of ATPase cation pump functionality. ³⁷ However, the potential impacts of using rejuvenated red cells are unclear, including the contributions of solution components, iron homeostasis, oxidative metabolites (such as hypoxanthine), and long‐term circulation post‐transfusion. Thus, clinical trials are warranted to validate the safety and efficacy of rejuvenated RBCs, especially for massive transfusion cases.

5.3. Platelet additive solutions

Platelet additive solutions (PAS) are designed to preserve platelet function during storage. PAS also dilute fibrinogen and coagulation factors by replacing 60–70% of plasma, thereby reducing unintended platelet activation and the risk of transfusion reactions. ³⁹ , ⁴⁰ , ⁴¹ , ⁴² , ⁴³ The components of PAS vary but generally include acetate, citrate, phosphate, potassium, magnesium, and glucose, which serve as metabolic fuels for the citric acid cycle, act as pH buffers, and help maintain normal platelet morphology. ⁴⁰ , ⁴⁴ , ⁴⁵ , ⁴⁶ More recently, PAS are also being used for cold‐stored platelets (CSP). Traditionally, platelets are stored at room temperature (20–24°C), requiring constant agitation and limiting shelf‐life to 5–7 days. ⁴⁷ Murphy and Gardner showed in 1969 that CSP rapidly clears from circulation after transfusion and ultimately may not be the best product for oncology patients. ⁴⁸ These findings led to wide acceptance of room‐temperature platelet storage despite reduced aggregation function versus “activated” cold‐stored platelets. ⁴⁸ , ⁴⁹ The disadvantages of room‐temperature platelets—including increased risk of bacterial growth, storage lesions, and ultimately decreased hemostatic function, which reduce their viability for supporting acute bleeding—brought about efforts to reevaluate CSP in the context of acute hemorrhage, as CSP possess beneficial in vitro characteristics, including increased hemostatic function and procoagulant activity. ⁵⁰ , ⁵¹ , ⁵² , ⁵³

In 2023, the FDA granted an exception to practice (variance) allowing platelets to be continuously stored for up to 14 days at 1 to 6°C, intended for use in active bleeding when room temperature platelets are not available or practical. ⁵⁴ The FDA's authorization of this new guidance was enacted to account for the limited bioavailability of platelet supply or when the use of conventional platelets is not practical, including but not limited to prehospital, austere, or rural settings, or in mass casualty/public emergency events. ⁵⁴ This guidance allows platelets to be stored in either plasma or PAS.

Although in vitro data from various studies suggest the specific advantages of CSP over room‐temperature stored platelets, ⁵⁰ , ⁵¹ , ⁵² , ⁵³ clinical data are currently lacking. Efforts to fill this data gap were investigated by Strandenes et al., who compared room‐temperature stored platelets versus CSP stored for up to 14 days in randomized adults undergoing semi‐urgent complex cardiothoracic surgery. ⁵⁵ Although limited by sample size, the study revealed no significant differences between measured clinical effect (chest drain output) and platelet functionality assessed by thromboelastography, alluding to a plausible non‐inferiority conclusion. ⁵⁵ Scaling beyond pilot data, the CHIlled Platelet Study (CHIPS; NCT04834414) is a Phase III, randomized, partially blinded, non‐inferiority, platelet storage study performed at 20 clinical centers that completed enrollment as of July 2025, comparing the transfusion efficacy of room‐temperature stored platelets vs. CSP (with a max storage duration of 21 days in either plasma or PAS) in both adult and pediatric patients undergoing complex cardiac surgical procedures. ⁵⁶ The outcomes of this study are intended not only to expand platelet reserves but also to demonstrate that CSP provides better hemostatic efficacy versus room‐temperature stored platelets, ideal for trauma resuscitation and acute hemorrhage control. ⁵¹ , ⁵² , ⁵⁶ , ⁵⁷

6. DEOXYGENATION/ANAEROBIC STORAGE: HYPOXIC RBCs

Isolated RBCs stored for long durations under hypothermic conditions accumulate physical and metabolic perturbations due to accumulated oxidative damage, which consequently decreases their viability and function ¹⁸ and leads to hemolysis and shortened RBC survivability in post‐transfusion recipients. ⁵⁸ , ⁵⁹ Deoxygenation and anaerobic storage (DAS) methods mitigate these pro‐inflammatory effects, subsequently leading to preserved ATP and 2,3‐DPG levels, improved RBC structural integrity, and decreased hemolysis rates. ⁶⁰ Mechanistically, DAS lowers oxygen content (thus mitigating prooxidant reactions) prior to cold storage and maintains this hypoxic environment throughout storage. ¹⁸

In 2007, Yoshida et al. illustrated this process with a stepwise deoxygenation method involving repetitive gas exchange in multiple RBC units using AS‐3 followed by six cycles of 10‐minute exposure to ultra‐pure argon gas. ⁶⁰ Deoxygenated RBC units were then cold‐stored in vented anaerobic chambers to prevent reoxygenation and compared against standard controls. ⁶⁰ Deoxygenated RBCs with AS‐3 had significantly less hemolysis, more ATP (79 ± 24% remaining ATP at 10 weeks vs. 36 ± 12% for aerobic units), and improved membrane stability after 6 weeks. ⁶⁰ Transfusion of six participants with similarly prepared RBCs, exposed to DAS conditions for up to 8 weeks, met FDA guidelines (<0.8% overall hemolysis and 24‐h post‐transfusion RBC >75%), effectively prolonging RBC storage by at least 2 weeks. ⁶⁰ , ⁶¹ Additionally, DAS improved 24‐h autologous post‐transfusion RBC mean recovery (83.1 ± 5.4%) compared to previous reports (73.5 ± 13.7%). ⁶⁰ , ⁶² Dumont et al. investigated the cause of these metabolic benefits by controlling CO₂ removal during DAS and derived that significantly higher 2,3‐DPG concentrations were associated with CO₂ removal, while the increased ATP levels were secondary to deoxygenation. ⁶³

Hemanext was recently granted de novo authorization in the U.S. for a DAS process that eliminates the need for inert gases or a separate anaerobic storage canister. ⁶⁴ The Hemanext ONE system is designed for processing and storing leukocyte‐reduced RBCs for up to 42 days with reduced oxygen and carbon dioxide concentrations. The system uses a specialized Oxygen Reduction Bag and Storage Bag to control O₂ and CO₂ concentrations, with strict protocols for processing within 12 h of collection. ⁶⁵ Alessandro et al. conducted a small two‐arm cross‐sectional study with 12 healthy volunteers donating two units of blood: one cold‐stored aerobically and the other utilizing the Hemanext ONE system. ⁶⁶ Autologous 24‐h post‐transfusion RBC recovery after 42 days revealed a significant increase of hypoxic RBCs over standard controls (90.2 ± 6.5% vs. 87.3 ± 4.1% in aerobic controls) without exceeding >1% overall hemolysis. ⁶⁶

Early clinical transfusion studies confirm the feasibility and safety of hypoxic RBCs, with the potential to extend shelf‐life, preserve cell quality, and enhance oxygen delivery, amplifying the biological and logistical benefits of DAS. The logistical benefit of hypoxic RBCs would enable strategic stockpiling of blood reserves without compromising functional viability. However, large randomized controlled trials (RCTs) in critically injured patients would be required to delineate the effectiveness of hypoxic RBCs in trauma.

7. CRYOPRESERVATION

7.1. Cryopreserved red blood cells

Cryopreservation of red blood cells (CPRBC) is the process of storing RBC units in temperatures below −65°C, which reduces metabolism and arrests biochemical reactions within RBCs, allowing for long‐term storage. ⁶⁷ CPRBC was first implemented at scale aboard U.S. Navy ships in 1956 and saw successful usage during the Vietnam War but never entered widespread implementation. The advent of glycerolization (a cryoprotective process achieved by adding 40% weight per volume of glycerol) allowed for the storage of blood products for up to 10 years, ⁶⁸ with experimental storage durations reaching up to 37 years. ⁶⁹ However, glycerol causes osmotic lysis upon transfusion, making post‐thaw deglycerolization a necessary yet cumbersome step ⁶⁸ taking ~95 to 105 min, including thawing time. ⁷⁰ Novel strategies to reduce CPRBC processing time are warranted to improve operational readiness of the product. ⁶⁷ , ⁷¹ Although not widely used in the majority of military blood banks and national stockpiles, ⁷² it should be noted that the Association for the Advancement of Blood & Biotherapies provided guidance on the retirement of one of the major CPRBC automated cell processors, the COBE® 2991 (Terumo BCT, Lakewood, CO, USA), planned for complete discontinuation in March 2031. ⁷² , ⁷³ This open‐system workflow was limited by a 24‐h post‐thaw shelf‐life, operator‐dependent glycerolization, non‐integrated pre‐/post‐thaw processing steps, and a higher risk of microbial contamination, whereas the closed‐system ACP‐215 (Haemonetics Corporation, Braintree, MA, USA) streamlines both glycerolization and deglycerolization and extends post‐thaw shelf‐life to 14 days when resuspended in AS‐3. ⁷² , ⁷⁴ , ⁷⁵ , ⁷⁶

From a military perspective, thawed and deglycerized CPRBCs are largely limited to Role 2 and higher Medical Treatment Facilities (MTFs), due to their 14‐day post‐processing shelf‐life in 1–6°C. ⁷⁰ , ⁷⁷ Therefore, the primary role for CPRBCs in military medicine is supplementing LTOWB during periods of increased demand. ⁷⁰ Attempts to improve the process include Liu et al.'s dilution‐filtration method that sought to reduce the deglycerolization time of porcine erythrocytes at the cost of lower RBC recovery compared to the standard automated cell washers used today. ⁷⁰ , ⁷⁸ , ⁷⁹

7.2. Cryopreserved platelets

Hematologist Robert C. Valeri developed a method for cryopreservation of platelets (CPP) at the Naval Blood Research Laboratory, utilizing 6% dimethyl sulfoxide (DMSO) as a cryoprotectant and allowing for storage at −80°C for up to 2 years. ⁸⁰ Valeri also introduced a “no‐wash” procedure before freezing, removing ~95% of the DMSO and reducing post‐thaw preparation time to about 10 min ⁸¹ with a post‐thaw shelf‐life of 4 to 6 h. ⁸² , ⁸³ Compared to liquid‐stored platelets, cryopreserved platelets exhibit accelerated clotting time and significantly stronger clot firmness measured by thromboelastography. ⁸⁰ , ⁸⁴ , ⁸⁵

Due to the activated phenotype of CPP, their use is more optimal for acute hemorrhage and trauma rather than prophylactic administration. ⁸⁶ , ⁸⁷ A 1999 randomized clinical trial of 53 patients comparing cryopreserved to conventional liquid platelet transfusion during cardiopulmonary bypass surgery revealed no adverse sequelae and showed decreased median blood loss (1721 mL vs. 2298 mL) and decreased overall blood product usage. ⁸⁰ , ⁸⁸ More recently, a pilot randomized clinical trial revealed no adverse post‐transfusion events in either liquid‐stored platelets or CPP. ⁸⁹

Additionally, CPP has been successfully implemented in military MTFs, with the Dutch Military Blood Bank incorporating frozen platelets amid coalition force deployments in Afghanistan between 2006 and 2010 during an introduction of massive transfusion protocols. ⁸⁷ Protocols that included frozen blood products led to improved mortality rates and a very low incidence of transfusion reactions (1 out of 3060 transfused products). ⁸⁷ Several notable advancements have happened in 2025. Cellphire's CLPH‐511 CPP offers extended storage up to 5 years at ≤ −65°C with an injectable suspension that reduces thaw time to approximately 15 min ⁹⁰ and has received FDA Fast Track designation for the treatment of acute hemorrhage when conventional platelets are not readily available. ⁸⁷ , ⁹⁰ CLPH‐511 recently completed a multicenter RCT evaluating its non‐inferiority or superiority to liquid‐stored platelets in patients undergoing Cardiopulmonary Bypass Surgery (CRYPTICS trial). ⁹¹ The primary endpoint was measured as the total blood volume in chest tube drainage 24 h postoperatively, with preliminary data meeting the primary efficacy endpoint (Difference in least‐square means: 142.0 mL; 95.576% CI of volume difference below the noninferiority margin). Vitrafy Life Sciences' rapid cryopreservation platform also demonstrated CPP that achieved greater than 88% post‐thaw recovery and demonstrated regulatory‐grade hemostatic function in commercial unit sizes. ⁹² Furthermore, two large, blinded, multicenter, randomized, controlled clinical trials during complex surgical operations comparing CPP versus liquid platelets (CLIP‐II and CLIPNZ‐II trials) were completed, with results awaiting publication. ⁸²

In the context of LSCO or mass‐casualty events, having a platelet product with a 2‐year shelf‐life will augment the immediate need for platelet collection efforts. However, it is worth noting that the distribution of freezers and thawers will be required throughout the military theater and public sectors in order to maintain an inventory of CPP.

8. GENERAL LYOPHILIZATION OF BLOOD PRODUCTS

Lyophilization, or “freeze‐drying”, is a sublimation‐based technique that involves the removal of water and solvents from blood products. ⁹³ Freeze‐dried blood products are attractive due to their smaller footprint, increased shelf‐life, and increased stability at room temperature. Their prepared storage formulation allows for immediate reconstitution with an appropriate liquid, such as sterile water, without reliance on a refrigerated temperature‐controlled supply chain. This capability can significantly expand the availability of blood products in prehospital environments, offering clear logistical benefits in LSCO. Lyophilized blood products in the forward‐deployed environment (pre‐Role 2) could reduce or eliminate cold‐chain and temperature tag data collection requirements and allow for strategic positioning and stockpiling. ¹²

8.1. Lyophilization of plasma

The lyophilization of plasma products dates back to the 1930s from canine traumatic shock resuscitation experiments. ⁹⁴ During World War II, lyophilized plasma was mass‐produced and widely distributed, mostly by the American Red Cross, with more than 10 million units of pooled lyophilized plasma created for Allied Forces. ⁹⁵ , ⁹⁶ , ⁹⁷ In 1950, French military physician Jean Julliard adopted the use of freeze‐dried plasma (FDP) alongside the establishment of the French Military Blood Institute (Centre de Transfusion Sanguine des Armées), which is still producing FDP for military and austere civilian populations today. ⁹⁸ , ⁹⁹ , ¹⁰⁰ Lyophilized plasma has had widespread use in South Africa, Germany, and the Israel Defense Forces Medical Corps, with United States Army Special Operations Forces using French‐produced FDP under an emergency use authorization (EUA). ⁹³ , ⁹⁵ , ¹⁰¹ , ¹⁰² , ¹⁰³ , ¹⁰⁴ , ¹⁰⁵

FDP can be easily reconstituted (less than 6 min), with post‐transfusion coagulation profiles comparable to those of thawed plasma, making it desirable as a first‐line blood product that reduces transfusion time for combat casualties facing long transport times. ¹⁰⁶ Donors traditionally undergo rigorous medical screening to verify appropriate coagulation factor levels with an active hemovigilance program to ensure trace‐back. ⁹⁸ Large batch production of dried plasma products requires vigilant pathogen control; pathogen reduction techniques include photochemical inactivation (where molecules such as amotosalen bind to the genetic material of pathogens, followed by ultraviolet light exposure for inactivation ⁹⁵ , ¹⁰⁷ ) and solvent‐detergent treatments (which disrupt lipid‐enveloped viruses and bacteria, followed by filtration for their removal). Recent advancements in these treatments incorporate prion removal and improved preservation of clotting factors as well. ⁹⁵ , ¹⁰⁸

In a systematic review of 12 studies, FDP use during major trauma cases showed no significant differences in mortality rates or the need for transfusion of allogeneic blood products when compared to thawed plasma. ¹⁰⁶ Although there are currently no fully approved U.S.‐manufactured FDP products, efforts are ongoing, with FDA approval expected imminently. ¹⁰⁹ OctaplasLG Powder, a lyophilized version of Octapharma's FDA‐approved Octaplas (pooled plasma treated with the aforementioned solvent‐detergent), received Emergency Use Authorization (EUA) within the Department of Defense in August 2024. ¹⁰⁹ The EUA currently enables U.S. military forces to acquire, distribute, and store OctaplasLG for use in treating hemorrhage or coagulopathy when traditional plasma is unavailable or impractical.

8.2. Spray‐drying of plasma

Spray‐drying (SD) involves subjecting liquid plasma to high‐pressure gases through a small nozzle, creating particle liquid droplets. These droplets are then exposed to temperatures of up to 150°C, followed by rapid evaporation and cooling to generate a dry, stable powder. ⁹⁵ This is an evaporation‐based process that results in a powder formulation that can be easily reconstituted with the appropriate solution. SD plasma harbors similar logistical benefits to FDP, although the two products are distinct.

An in vitro study by Booth et al. showed that SD resulted in decreased Factor VIII activity and von Willebrand factor antigen activity compared to fresh frozen plasma (FFP), ¹¹⁰ although Spinella et al. observed overall higher total thrombin generation compared to both FDP and FFP. ¹¹¹ Animal studies comparing SD and FFP in a polytrauma, hemorrhagic shock swine model showed that SD was equally effective as FFP in reversing trauma‐associated coagulopathy and improving survival. ¹¹² Other newer and notable products include FrontlineODP, produced by Velico Medical's single‐unit SD technology, which preserves coagulation factors with short reconstitution times (3 to 4 min) and storage up to 2 years. ¹¹³ , ¹¹⁴ , ¹¹⁵ FrontlineODP recently completed its phase I clinical trial sponsored by the Biomedical Advanced Research and Development Authority. ¹¹⁶ , ¹¹⁷

8.3. Lyophilization of platelets

The limited shelf‐life of platelets has spurred research into a lyophilized form. ¹¹⁸ Thrombosomes (Cellphire Therapeutics) are a platelet‐derived hemostatic agent (PDHA) manufactured from pooled blood group O platelets that are trehalose‐loaded to stabilize membranes and prevent ice crystal formation. ¹¹⁹ Thrombosomes have a 3‐year shelf‐life at room temperature, can be reconstituted in sterile water within 2–3 min, and present with activated surface markers, potentially improving bleeding control. ¹²⁰ A phase I study found acceptable safety outcomes in 24 bleeding, thrombocytopenic patients with hematological malignancies who received PDHA doses of up to 3.78 X 10⁸ particles/kg. ¹²⁰ PDHAs are currently undergoing Phase 2 clinical trials. ¹²⁰ , ¹²¹

8.4. Lyophilized red blood cells

In 1992, Cliff et al. evaluated the stability of lyophilized lipid‐encapsulated hemoglobin, and Goodrich et al. established that concentrated, washed, and lyophilized human RBCs preserved metabolic function. ¹²² , ¹²³ Han et al. further developed the concept by demonstrating that a protective solution of 40% polyvinylpyrrolidone, 25% human serum albumin, and 5% DMSO produced an increased cell recovery rate of 80%. ¹²⁴ Other studies have demonstrated that trehalose loading in RBCs decreases hemolysis due to the disaccharide's ability to replace water molecules' hydrogen bonds during dehydration, which stabilizes cellular membranes and prevents degradative pathways. ¹²⁵ Additionally, the inclusion of phospholipid vesicles in the lyophilization buffer has been shown to increase cell survival and further reduce hemolysis rates. ¹²⁶ Only one published clinical study of nonsynthetic lyophilized RBC exists, a 1992 early clinical study of four volunteers revealing low recovery secondary to rapid hepatic and splenic sequestration. ¹²⁷ However, multiple pre‐clinical efforts are underway using modern stabilization techniques and production equipment. ¹²⁸ , ¹²⁹

8.5. Biosynthetics

The reliance on blood products and potential supply gaps has generated renewed interest in biosynthetic human blood substitutes. Ideally, these biosynthetic blood products would be stable in the austere environment and a viable resuscitation option when donated blood is unavailable. Worth mentioning is ErythoMer, a lyophilized product composed of recycled human hemoglobin encased in deformable, hybrid peptidic‐lipid nanoparticles and serving the purpose of the endogenous RBC. ¹³⁰ , ¹³¹ Similarly, SynthoPlate can also be freeze‐dried and is an IV platelet‐mimetic liposomal nanoparticle coated with peptide triggers that activate its aggregation. ¹³² Both platforms remain under development with demonstrated efficacy in preclinical hemorrhage models and would substantially increase the shelf‐life of their blood component equivalent. ¹³¹ , ¹³²

9. DISCUSSION

Hemorrhage is the primary cause of preventable in‐hospital deaths in U.S. civilian trauma centers and accounted for 90.9% of potentially survivable prehospital deaths during Operation Iraqi Freedom and Operation Enduring Freedom. ¹ , ¹³³ Restoring blood volume is the best way to prevent hemorrhage‐associated deaths, but the limitations on blood product shelf‐life often contribute to restrictive usage, especially prehospital, in order to prevent waste and ensure supply in hospitals. This narrative review aimed to identify methods to prolong the shelf‐life of blood products and therefore enhance their availability wherever resuscitation is needed, even at the point of injury.

Several studies have revealed promising combinations of methods that would allow for shelf‐life extension during the storage of blood products and introduced new opportunities to logistically improve blood support infrastructure. Stretching current anticoagulant and additive solution capabilities has been low‐hanging fruit, and renewed interest in the cryopreservation and freeze‐ or spray‐drying of blood elements offers potentially dramatic improvements in the duration and functional capacity of stored blood products. It's worth noting that a current limitation is that donor screening does not assess coagulation status. However, the manufacturer of the dried blood product will need to comply with FDA regulations by setting quality control parameters for its product, such as potency and stability, to ensure consistency between manufactured lots. ¹³⁴

Currently, the FDA allows refrigerated storage of RBCs for up to 42 days and platelets for only 14 days (when conventional, room‐temperature, 5–7 day stored platelets are not available or their use is not practical). The benefits of early resuscitation with whole blood are well described; however, since functional clotting parameters are not characterized, the question remains if the transfused unit was the most efficient product to reverse coagulopathy or adequately support hemostasis. ¹³⁵ , ¹³⁶ , ¹³⁷

Since RBCs and platelets have distinct physiology and metabolism, decades of research have been conducted to address the storage lesions of these cells. Understanding the mechanisms underlying the metabolic, cytoskeletal, and other deficiencies that occur in these cells throughout the course of storage will provide new therapeutic targets to extend blood shelf‐life. In the meantime, more clinical studies to elucidate the specific implementations of these combined practices are needed to understand the risk versus benefit of changing blood product storage policies to accommodate increased blood supply demand.

While the blood research community continues to explore novel techniques to extend blood product shelf‐life, during instances of blood product surge (LSCO, mass casualty events, pandemics, etc.), blood centers and transfusion services will need to implement lessons learned from previous periods of blood shortages. ¹³⁸ Blood centers will need to increase donor recruitment, be aware of the supply chain, consider utilizing alternative approved collection kits, potentially adopt nonconforming manufacturing processes, support adequate staffing and training needs, leverage neighboring or regional blood banks to share inventory, and consider shipping inventory nationally. ¹³⁸ , ¹³⁹ Transfusion services will need to implement conservation methods, such as triage priority, splitting units, canceling elective surgeries, and, in extreme instances, consider utilizing expired products. ¹³⁸ Riley et al. have shown there was no association in mortality when combat trauma patients were transfused with expired blood products up to 1 week past expiration; however, this practice should be approached with caution and careful risk assessment. ¹⁴⁰ Adopting new blood products remains challenging due to the cost of development, the necessary large‐scale multiple‐phase clinical trial requirements, and the lack of clear future reimbursement rates. ¹⁴¹ , ¹⁴² Despite these challenges, blood centers will continue to improve on prior lessons learned, plan, and train for future shortages. Additionally, the Armed Services blood program has the opportunity to implement novel blood solutions under an EUA, which may offset future wartime blood shortages. ¹⁴³

CONFLICT OF INTEREST STATEMENT

The authors have disclosed no conflicts of interest.

Akaraphanth M, Oudakker J, Paulson M, Meledeo MA, Reddoch‐Cardenas KM, Xiang L, et al. Narrative review of strategies for blood product shelf‐life extension. Transfusion. 2026;66(Suppl. 1):S350–S367. 10.1111/trf.70037

DATA AVAILABILITY STATEMENT

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.