Next Article in Journal
Manipulating the Epigenome in Nuclear Transfer Cloning: Where, When and How
Next Article in Special Issue
P2Y11 Agonism Prevents Hypoxia/Reoxygenation- and Angiotensin II-Induced Vascular Dysfunction and Intimal Hyperplasia Development
Previous Article in Journal
An Insight into the Role of Non-Porphyrinoid Photosensitizers for Skin Wound Healing
Previous Article in Special Issue
Evaluation of Liver Quality after Circulatory Death versus Brain Death: A Comparative Preclinical Pig Model Study
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Oxygen Transport during Ex Situ Machine Perfusion of Donor Livers Using Red Blood Cells or Artificial Oxygen Carriers

Section of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Surgical Research Laboratory, Department of Surgery, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Organ Preservation & Resuscitation Unit, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Department of Abdominal Transplantation Surgery and Coordination, University Hospitals Leuven, 3000 Leuven, Belgium
Transplantation Research Group, Department of Microbiology, Immunology, and Transplantation, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
Department of Critical Care, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Author to whom correspondence should be addressed.
Int. J. Mol. Sci. 2021, 22(1), 235;
Submission received: 16 November 2020 / Revised: 14 December 2020 / Accepted: 24 December 2020 / Published: 28 December 2020
(This article belongs to the Special Issue Protective Strategies against Organ Ischemic Injury)


Oxygenated ex situ machine perfusion of donor livers is an alternative for static cold preservation that can be performed at temperatures from 0 °C to 37 °C. Organ metabolism depends on oxygen to produce adenosine triphosphate and temperatures below 37 °C reduce the metabolic rate and oxygen requirements. The transport and delivery of oxygen in machine perfusion are key determinants in preserving organ viability and cellular function. Oxygen delivery is more challenging than carbon dioxide removal, and oxygenation of the perfusion fluid is temperature dependent. The maximal oxygen content of water-based solutions is inversely related to the temperature, while cellular oxygen demand correlates positively with temperature. Machine perfusion above 20 °C will therefore require an oxygen carrier to enable sufficient oxygen delivery to the liver. Human red blood cells are the most physiological oxygen carriers. Alternative artificial oxygen transporters are hemoglobin-based oxygen carriers, perfluorocarbons, and an extracellular oxygen carrier derived from a marine invertebrate. We describe the principles of oxygen transport, delivery, and consumption in machine perfusion for donor livers using different oxygen carrier-based perfusion solutions and we discuss the properties, advantages, and disadvantages of these carriers and their use.

1. Introduction

Novel approaches are being explored to increase the number and quality of donor organs. These methods are aimed to decrease the donor organ shortages in relation to the number of candidate recipients on the waiting list [1]. One such approach is dynamic or machine preservation of donor organs. Machine perfusion (MP) is a procedure whereby organs are perfused ex situ after procurement. The aims of MP are multiple and include mitigation of ischemia-reperfusion injury (IRI), ability to prolong preservation time ex situ, improvement of organ condition and function, and assessment of organ viability prior to transplantation [2,3,4]. Currently, MP is widely studied and perfusion systems have been developed for various organs, including liver, heart, kidneys, and lungs [5].
MP of donor livers can be performed at different temperatures depending on the goal of the perfusion. For clinical use, temperature ranges are divided into three categories [6]. Hypothermic machine perfusion (HMP) ranges from 0 °C to 12 °C, at which the metabolic rate and energy expenditure of the organ is low. Oxygenated HMP mitigates IRI due to the resuscitation of mitochondria prior to warm reperfusion in the recipient. HMP can restore levels of intercellular adenosine triphosphate (ATP), reduce the production of reactive oxygen species (ROS), and confer protection to the bile ducts [7,8,9]. During HMP, organ viability and function cannot be assessed, because the liver is in a low metabolic state, but in addition it may prolong preservation time [10,11]. Subnormothermic machine perfusion (SNMP) ranges from 24 °C to 34 °C. During SNMP, at temperatures between 30 °C and 33 °C, the rate of metabolism increases to nearly 70% of the normal rate at body temperature. SNMP has the ability to increase ATP-levels and decrease mitochondrial injury and possibly asses viability [12,13]. In normothermic machine perfusion (NMP) organs are perfused at a temperature between 35 °C and 38 °C. During NMP, the metabolic rate is at normal physiological levels and the viability of the hepatocytes and cholangiocytes can be assessed [14,15,16]. A potential benefit of NMP is the use for therapeutic interventions [17]. NMP is technically more challenging, because the fully functioning liver has higher oxygen (O2) demands than during HMP. MP methods which are in experimental or preclinical evaluation such as subzero and hyperthermia conditions are beyond the scope of this review and are discussed elsewhere [18,19].
MP procedures are performed with different perfusion solutions depending on the temperature range. In HMP, an elementary perfusion solution contains the following ingredients: gluconate, phosphate, glutathione, allopurinol, and hydroxyethyl starch. Perfusion with this solution serves to provide O2 and remove waste products continuously produced by the liver [20]. In NMP, the perfusion solution should contain at least an oxygen carrier (OC), nutrients to maintain metabolism, anticoagulation, and broad-spectrum antibiotics [21]. To obtain the preferred osmolality and colloid osmotic pressure, water, saline, and human albumin or another type of colloid are usually added [21,22].
In this descriptive review we discuss the principles of gas transport during ex situ MP. Our focus is on the impact of temperature on gas transport and the various natural and artificial oxygen carriers (AOC) that can be added to the perfusion solution during MP from hypothermia to normothermia. We reviewed the published literature regarding MP of human livers and principles of gas transport. Experimental and clinical studies are discussed.

2. Overview of Gas Transport in Machine Perfusion

2.1. Physiological Gas Transport

In humans, gas exchange takes place by diffusion in the alveoli. The diffusing capacity of carbon dioxide (CO2) is 20 times higher than that of O2 [23]. After diffusion, 97% of O2 is absorbed by the red blood cells (RBC) where each hemoglobin (Hb) molecule binds four O2 molecules to iron ions (Fe++) to form oxyhemoglobin. The remaining O2 dissolves into the plasma. In the cell, O2 is consumed by the mitochondria in aerobic respiration to produce ATP [24]. In the citric acid cycle, the acetyl group of acetyl-coA is oxidized and produces CO2, which is transported back to the alveoli in a dissolved state (approximately 7%), in the form of bicarbonate (70%), or bound to Hb to form carbaminohemoglobin (20%) [25,26]. Thus, the transport of CO2 depends less on a carrier system than O2. Because CO2 also has a better diffusing capacity across membranes than O2, transport of CO2 is rarely a rate-limiting factor in MP.

2.1.1. The Impact of Temperature on Gas Transport and Oxygen Requirements

Increasing blood temperature causes a right shift in the O2-Hb dissociation curve (Figure 1), supporting O2 release to the tissue. Increases in body temperature also lead to an increased metabolic rate, with higher O2 requirements. As is shown by the Van ‘t Hoff equation and the Arrhenius relation derived from it [27], the relation between metabolic rate and temperature is remarkably similar in various animal species, with an approximate 10% or 1.1-fold increase in metabolic rate per 1 °C (Figure 2) [28]. Likewise, increasing amounts of CO2 will be produced at higher temperatures [29].
When glucose is fully oxidized under steady-state conditions, the production of CO2 (V̇CO2) will be equal to the consumption of oxygen (V̇O2). The ratio between V̇CO2 and V̇O2 is called the respiratory quotient (RQ) and can be monitored in vivo or during ex situ MP. It is an important indicator of how ATP is generated. Glucose oxidation has an RQ of 1, whereas lipid oxidation has an RQ of <0.8 [23].

2.1.2. The Impact of Temperature on Gas Solubility and Pressure in Fluids

Blood consists for approximately 92% of water and O2 dissolves poorly in water [32]. The solubility of a gas into a fluid is determined by Henry’s law: “At a constant temperature, the amount of a given gas dissolved in a given type of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.” This implies that a rise in the partial pressure of O2 (PO2) leads to proportionally more dissolved O2 in the fluid if the temperature is constant [33]. Delete blank row under the Equation (use backspace)
Henry s   law :   c = k ·   P
c = concentration dissolved gas, k = Henry’s law constant, P = partial pressure (in mm Hg or kPa).
However, when the temperature increases, O2 solubility decreases. Thus, at low temperatures, more O2 can be dissolved in the water compartment of a solution [32]. To maintain the same O2 concentration in a high-temperature solution without an OC in comparison to a low-temperature solution, the PO2 should be increased (see Figure 1 and Figure 2).

2.1.3. Gas Transport in Machine Perfusion

During MP, O2 diffuses into the perfusate in the oxygenator, with a controlled gas flow and a set O2 fraction. The oxygenated perfusion solution enters the liver through the cannulated portal vein and, when dual perfusion is applied, also via the hepatic artery. The CO2 produced diffuses into the perfusate and circulates back to the oxygenator(s). The O2 content of the perfusate depends on the perfusate temperature, the administered O2 flow, and the concentration and use of either a cell-free solution or an OC-based solution.
Oxygenated HMP reduces IRI in contrast to non-oxygenated HMP or static cold storage (SCS) [7,16]. In hypothermic conditions the liver still maintains a low metabolic rate, therefore mitochondrial oxidative phosphorylation generates ATP when O2 is supplied. During oxygenated HMP the mitochondrial respiration decreases and ceases altogether after approximately 90 min [34]. At this point, the mitochondria have switched from a high-flux to a low-flux electron transfer stage. When O2 is not supplied to the solution, the mitochondria remain in the high-flux state electron transfer stage which causes the release of ROS during reperfusion [34,35,36].
The O2 requirements in HMP and SNMP can be met by adding dissolved O2 in the perfusion fluid [13,34]. In contrast, at 37 °C, the freely dissolved O2 concentration in blood is only 3%. As indicated in Figure 2, at higher temperatures, the O2 requirements exceed the maximal O2 delivery by dissolved O2 alone. It should also be noted, that the total delivery of O2 to any organ should be considerably larger than its consumption because of heterogeneity in O2 demand and metabolism. Consequently, a perfusion solution without an OC cannot supply sufficient O2 to the liver to maintain aerobic metabolism at normothermia [37,38].
In MP, oxygenation and CO2-removal are adjustable by controlling the gas flow and its O2 concentration (FiO2). The O2 and CO2 levels can be measured via arterial and venous blood gas analysis. In the arterial blood, the partial pressure of oxygen (aPO2), partial pressure of CO2 (aPCO2) and the percentage of Hb saturated with oxygen (asO2) can be measured. Likewise, the venous blood gas parameters vPO2, vPCO2 and vsO2 can be measured. Oxygen consumption can be reasonably accurately derived by subtracting the venous O2 content from the arterial O2 content.
Oxygen   consumption   =   V ̇ O 2   mL / min   =   blood   flow   ·   1.36 · Hb · asO 2 vsO 2   +   0.0031 · aPO 2 vPO 2
VO2 = oxygen consumption, bloodflow (L/min), Hb = hemoglobin (g/dL), sO2 = saturated oxygen (%), PO2 = perfusate partial pressure (mm Hg).
Similarly determining CO2 consumption is more challenging, as CO2 content is more difficult to accurately estimate in the arterial and venous samples.

3. Overview of Oxygen Carriers

As described above, ex situ MP of an isolated organ at normothermia requires the addition of an OC to the perfusion fluid to enable sufficient O2 delivery. Various OCs are currently used during machine preservation of donor organs. OCs have various characteristics resulting in different properties per carrier. In most studies on liver NMP, investigators have used RBCs as OC. Artificial alternatives are hemoglobin-based oxygen carriers (HBOCs) and natural extracellular OCs (Table 1, Figure 3).

3.1. Hemoglobin in Red Blood Cells

The human OC, Hb is transported by RBCs. Hb has a high affinity for O2 and a low affinity for CO2. One molecule of Hb can adsorb four molecules of O2. A higher concentration of Hb in the blood results in a higher capacity to transport O2. When an O2 molecule binds to Hb, the binding of additional O2 molecules is facilitated, which results in the S-shape of the O2-Hb dissociation curve (Figure 1). Human Hb further depends on 2,3-biphosphoglycerate, pH and temperature for its affinity for O2 [46].
It should be noted that when clinical laboratories report Hb concentrations in mmol/L, this concentration refers to the number of O2-binding sites and not to the actual number of Hb molecules. One molecule of Hb can bind to four O2 molecules and thus, in reality, a reported Hb of 10 mmol/L is only 2.5 mmol/L of Hb molecules. Accordingly, when Hb is expressed in mmol/L units, in order to calculate the total O2 content in a solution containing Hb, the amount of Hb should not be multiplied by 4 to arrive at the amount of O2 bound to Hb. This is, however, a common mistake in formulas that are used to calculate O2 consumption and it leads to an overestimation of O2 consumption by a factor 4. So, there is at least one advantage to the older formula that was based on the conventional unit g/dL: max O2 bound to Hb (mL/dL) = 1.36 Hb [47]. RBC-based perfusion solutions are only used in SNMP and NMP, due to hemolysis of the RBCs in a hypothermic environment. RBC are the most widely used OC in NMP [15,48,49,50]. Apart from Hb, RBCs also contain enzyme systems relevant for Hb protection and enhanced CO2 transport, such as methemoglobin-reductase and carbonic anhydrase. Some disadvantages of the use of RBCs are the relative scarcity of precious resources, immune-mediated phenomena, blood-borne infection transmission, and logistical difficulties with cross-matching. Considering that RBCs are a limited resource, alternative OCs have been examined for use in MP (Table 1) [51].

3.2. Hemoglobin-Based Oxygen Carrier

For decades, the development of AOCs has been a topic of extensive research. The first objective of AOCs was to substitute RBCs in blood transfusions to eliminate RBC-related side effects and to decrease the use of a scarce resource. Although the theoretical rationale for AOCs still exists, on account of the relatively short half-life and potential side effects when administered intravenously, the in vivo use of AOCs was never really successful. MP serves as a new niche for the application of AOCs because important systemic side effects are not relevant in MP. Clinical trials are currently using AOCs as possible substitutes for RBCs in the MP of single organs (Table 2) [52].

3.2.1. Hemoglobin-Vesicles

Hemoglobin-vesicles (Hb-Vs) are phospholipid vesicles containing human-derived Hb. The diameter of the vesicles is 250–280 nm, which is smaller than that of RBCs. Hb-Vs are saturated for 50% at an O2 pressure between 9 mm Hg and 30 mm Hg. They do not contain clinically relevant RBC antigens and have a longer shelf life than RBCs. Although Hb-Vs are small in comparison to RBCs, they are large compared to macromolecules (Figure 3) and accordingly do not generate a colloid osmotic pressure. The half-life of Hb-Vs is two to three days, which limits their use [66,67]. A few studies have reported on the use of Hb-Vs in porcine and rat MP models for livers and limbs [63,68,69]. The porcine models showed increased O2 consumption during SNMP and decreased alanine aminotransferase and lactate dehydrogenase levels after reperfusion compared to HMP and SNMP, without an additional OC [62,63].

3.2.2. Hemoglobin-Based Oxygen Carrier-201

The first-generation HBOCs prepared from modified tetramer Hb molecules, has been associated with vasoconstriction and renal dysfunction when administered intravenously. Clinical trials were suspended because of increased mortality, myocardial infarction, and stroke [70,71]. Hemoglobin-based oxygen carrier-201 (HBOC-201) can cause vasopressor effects due to a tetramer Hb, possibly through the binding of nitric oxide (NO) in the interstitial space, which leads to vasoconstriction and platelet aggregation. Additionally, HBOC-201 reduce the NO concentration due to its scavenging effects, which may explain the increased risk of myocardial infarction when administered intravenously [72,73]. However, many studies reevaluated the use of HBOC-201 and reported no evidence of NO-related toxic effects applicable to all HBOCs [74,75,76]. Later, clinical trials were performed using HBOC-201 in patients with severe anemia who could not receive whole blood products. Results indicated that patients with acute bleeding and hemolysis survived relatively longer than patients who did not receive HBOC-201 [77]. Currently, HBOC-201 is also used in US and European programs as a blood substitute for patients who do not accept transfusion with RBCs on account of their religious background [78]. In these compassionate use programs numerous patients have repeatedly received administration of HBOC-201 without clinical side effects (Z. Zafirelis, personal communication).
HBOC-201 or Hemopure® (HbO2 Therapeutics LLC, Cambridge, MA, USA) is the most frequently used HBOC in MP. HBOC-201 is a polymerized Hb synthesized from bovine Hb. The Hb is extracted from bovine RBCs, purified, and cross-linked with glutaraldehyde to increase the stability and the molecular size. A purification process excludes possible harmful blood borne transmissions so that the end-product is a sterile pyrogen-free solution. These OCs are smaller than RBCs, resulting in a less viscous fluid. The affinity for O2 in HBOC-201 depends on the chloride ion concentration. It releases O2 easier than human Hb, because of a right shift in the Hb-dissociation curve (Figure 1). The in vivo half-life of HBOC-201 is approximately 20 h, which is much shorter than the half-life of RBCs, but sufficient for most cases of ex situ organ MP. The O2 pressure required for 50% saturation of the O2-binding sites in HBOC-201 is 38–40 mm Hg, which is higher than for human Hb in RBCs. When completely saturated, HBOC-201 can bind 1.36 mL O2 per gram of Hb. It has a molecular weight of 250 kDa [51,55,79]. A disadvantage of HBOC-201 is the formation of methemoglobin (metHb), which is formed when Fe++ is oxidized to Fe+++. Because the natural metHb-reductase in the RBCs that reduces Fe+++ back to Fe++ is absent, this leads to a gradual increase in the metHBOC-201 concentration in the perfusion fluid. MetHBOC-201 is longer available for O2 transport, leading to a lower saturation in prolonged machine preservation [80]. MetHBOC-201 can be converted back to normal, functional HBOC-201 by (repeated) addition of glutathione or ascorbic acid [79].
In several clinical studies HBOC-201 served as the OC in the MP of donor organs (Table 2). Laing et al. concluded that HBOC-201 could be used as an alternative for RBCs in NMP [51]. Van Leeuwen et al. used HBOC-201 in the DHOPE-COR-NMP trial, rewarming discarded human donor livers from hypothermic to normothermic conditions. In this trial suboptimal livers were continuously perfused and oxygenated, which increased the utilization of initially discarded donor organs. An advantage of HBOC-201 is that it can be used during the HMP phase which avoids the need to change the perfusion fluid when one switches from hypothermia to normothermia [55,57,60]. After MP, the perfused organ is flushed, leaving only minimal amounts of HBOC-201 to reach the recipient. Apart from visceral organ MP, Vrselja et al. used HBOC-201 to perfuse porcine brains to study if brain circulation and cellular functions could be restored (Table 2) [59].

3.3. Natural Extracellular Oxygen Carrier Hemarina M101

The natural extracellular Hb equivalent Hemarina M101 (HEMO2life®, France) is obtained from a marine invertebrate: Arenicola marina, a lugworm. The molecule is quite large with a molecular weight of 3600 kDa. It is composed of 156 globins and 44 non-globin linker chains that can carry up to 156 O2 molecules when saturated, which results in a high O2-binding capacity. Hemarina M101 is active over a large range of temperatures (4 °C to 37 °C) and releases O2 according to a simple gradient that does not require any allosteric effector. The molecule possesses intrinsic Cu/Zn-superoxide dismutase antioxidant activity that, to a certain extent, protects tissue from superoxide radicals [81].
Hemarina M101 was first described as a new and potentially promising blood substitute in 1997. The initial transplantation-related research was performed by Thuillier et al. They demonstrated that Hemarina M101 has a beneficial effect during SCS before kidney transplantation by decreasing chronic fibrosis and organ dysfunction [82]. Alix et al. compared SCS solution with Hemarina M101 versus SCS solution alone during porcine liver graft preservation, showing higher ATP levels in the SCS with Hemarina M101 group after 80 min [42,83]. M101 was also used in preclinical trials as an additive to the perfusion solution during HMP in a marginal kidney porcine model. A reduction of short-term function loss and no loss of function or tissue integrity were observed (Table 1) [43,84].

3.4. Perfluorocarbons

Perfluorocarbons (PFCs) are hydrocarbons in which practically all hydrogen atoms are replaced by fluoride. They have a high capacity for dissolving respiratory gasses and have an O2 solubility that is 20 times higher than that of water. As in the case of water, the amount of O2 that can be dissolved in PFCs is determined by Henry’s law. A high partial O2 pressure is necessary to maximize O2 content of the PFCs (Figure 1). The O2 dissociation curve of PFCs is a straight line in contrast to the sigmoid curve of Hb in RBCs. For the intravascular use of PFCs, the lipophilic molecule should be formulated as an emulsion, which inevitably will reduce its overall O2 content. PFCs have been used in static cold preservation with active and non-active oxygenation [85,86]. In 1994 PFCs were already used in a pulsatile subnormothermic setting for the preservation canine kidneys [64]. Recently, PFCs were used during porcine ex vivo lung perfusion, which showed better preservation of mitochondrial function, glucose consumption and neutrophil infiltration [65].

4. Future Perspectives

The majority of OCs used in clinical MP of donor organs are RBCs. HBOC-201 may be a promising alternative to RBCs in MP. The ideal perfusion solution should contain a cell-free OC that can be used for MP at all temperatures, and it should have a long shelf life. Future research should aim to elucidate the relation between metabolic rate and required O2 delivery in donor organs.

5. Summary

MP is a dynamic organ preservation platform technology used to increase the number and quality of donor organs. It can be performed at different temperatures of the perfusate solution–varying from hypothermic to normothermic perfusion. Low temperatures lead to a decreased metabolic rate, while at 37 °C the organ is metabolically active at a physiological level.
At normothermia, oxidative phosphorylation is required to generate sufficient ATP. In MP, O2 is added to the perfusion solution through the oxygenators, while CO2 diffuses out passively through the oxygenators. The O2 requirements in HMP and SNMP can be met with dissolved O2 in the perfusion fluid. Because O2 solubility decreases with increasing temperatures, in NMP a perfusion solution containing an OC is required.

Author Contributions

Conceptualization, R.J.P. and V.E.D.M. data curation, S.B.B.; writing—original draft preparation, S.B.B.; writing—review and editing, O.B.v.L., R.U., B.L., D.M., T.L. and A.M.T.; visualization, M.W.N.N. and S.B.B.; supervision, R.J.P., V.E.D.M. and M.W.N.N. All authors have read and agreed to the published version of the manuscript.


This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data sharing not applicable.


We acknowledge the help of T. Van Wulfften Palthe, for assistance with language-editing.

Conflicts of Interest

The authors declare no conflict of interest.


AOCartificial oxygen carrier
aPCO2arterial partial pressure of carbon dioxide
aPO2arterial partial pressure of oxygen
ATPadenosine triphosphate
asO2arterial percentage of Hb saturated with oxygen
CO2carbon dioxide
Fe++iron ion
FiO2fraction of inspired oxygen
HBOChemoglobin-based oxygen carrier
HBOC-201hemoglobin-based oxygen carrier-201
HMPhypothermic machine perfusion
IRIIschemia reperfusion injury
MPmachine perfusion
NMP normothermic machine perfusion
NOnitric oxide
OCoxygen carrier
PCO2partial pressure of carbon dioxide
PO2partial pressure of oxygen
RBCred blood cell
ROSreactive oxygen species
RQrespiratory quotient
SCSStatic cold storage
SNMPsubnormothermic machine perfusion
SO2oxygen saturation
VCO2production of CO2
VO2consumption of O2
vPCO2venous partial pressure of carbon dioxide
vPO2venous partial pressure of oxygen
vsO2venous percentage of Hb saturated with oxygen


  1. Adam, R.; Karam, V.; Cailliez, V.; O Grady, J.G.; Mirza, D.; Cherqui, D.; Klempnauer, J.; Salizzoni, M.; Pratschke, J.; Jamieson, N.; et al. 2018 Annual Report of the European Liver Transplant Registry (ELTR)-50-year evolution of liver transplantation. Transpl. Int. 2018, 31, 1293–1317. [Google Scholar] [CrossRef] [Green Version]
  2. Monbaliu, D.; Brassil, J. Machine Perfusion of the Liver: Past, Present and Future. Curr. Opin. Organ Transplant. 2010, 15, 160–166. [Google Scholar] [CrossRef]
  3. Weeder, P.D.; van Rijn, R.; Porte, R.J. Machine Perfusion in Liver Transplantation as a Tool to Prevent Non-Anastomotic Biliary Strictures: Rationale, Current Evidence and Future Directions. J. Hepatol. 2015, 63, 265–275. [Google Scholar] [CrossRef] [Green Version]
  4. De Meijer, V.E.; Fujiyoshi, M.; Porte, R.J. Ex Situ Machine Perfusion Strategies in Liver Transplantation. J. Hepatol. 2019, 70, 203–205. [Google Scholar] [CrossRef] [Green Version]
  5. Salehi, S.; Tran, K.; Grayson, W.L. Focus: Medical Technology: Advances in Perfusion Systems for Solid Organ Preservation. Yale J. Biol. Med. 2018, 91, 301. [Google Scholar]
  6. Karangwa, S.; Dutkowski, P.; Fontes, P.; Friend, P.; Guarrera, J.; Markmann, J.; Mergental, H.; Minor, T.; Quintini, C.; Selzner, M. Machine Perfusion of Donor Livers for Transplantation: A Proposal for Standardized Nomenclature and Reporting Guidelines. Am. J. Transplant. 2016, 16, 2932–2942. [Google Scholar] [CrossRef]
  7. Dutkowski, P.; Polak, W.G.; Muiesan, P.; Schlegel, A.; Verhoeven, C.J.; Scalera, I.; De Oliveira, M.L.; Kron, P.; Clavien, P. First Comparison of Hypothermic Oxygenated Perfusion versus Static Cold Storage of Human Donation After Cardiac Death Liver Transplants. Ann. Surg. 2015, 262, 764–771. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  8. Dutkowski, P.; Schlegel, A.; de Oliveira, M.; Müllhaupt, B.; Neff, F.; Clavien, P. HOPE for Human Liver Grafts obtained from Donors After Cardiac Death. J. Hepatol. 2014, 60, 765–772. [Google Scholar] [CrossRef]
  9. Westerkamp, A.C.; Karimian, N.; Matton, A.P.; Mahboub, P.; van Rijn, R.; Wiersema-Buist, J.; de Boer, M.T.; Leuvenink, H.G.; Gouw, A.S.; Lisman, T.; et al. Oxygenated Hypothermic Machine Perfusion After Static Cold Storage Improves Hepatobiliary Function of Extended Criteria Donor Livers. Transplantation 2016, 100, 825–835. [Google Scholar] [CrossRef] [Green Version]
  10. Schlegel, A.; Kron, P.; Dutkowski, P. Hypothermic Machine Perfusion in Liver Transplantation. Curr. Opin. Organ Transplant. 2016, 21, 308–314. [Google Scholar] [CrossRef] [Green Version]
  11. Brüggenwirth, I.M.; van Leeuwen, O.B.; de Vries, Y.; Bodewes, S.B.; Adelmeijer, J.; Wiersema-Buist, J.; Lisman, T.; Martins, P.N.; de Meijer, V.E.; Porte, R.J. Extended Hypothermic Oxygenated Machine Perfusion Enables Ex Situ Preservation of Porcine Livers for Up to 24 Hours. JHep Rep. 2020, 2, 100092. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  12. Spetzler, V.N.; Goldaracena, N.; Echiverri, J.; Kaths, J.M.; Louis, K.S.; Adeyi, O.A.; Yip, P.M.; Grant, D.R.; Selzner, N.; Selzner, M. Subnormothermic Ex Vivo Liver Perfusion is a Safe Alternative to Cold Static Storage for Preserving Standard Criteria Grafts. Liver Transplant. 2016, 22, 111–119. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  13. Bruinsma, B.G.; Yeh, H.; Özer, S.; Martins, P.N.; Farmer, A.; Wu, W.; Saeidi, N.; Op den Dries, S.; Berendsen, T.A.; Smith, R.N. Subnormothermic Machine Perfusion for Ex Vivo Preservation and Recovery of the Human Liver for Transplantation. Am. J. Transplant. 2014, 14, 1400–1409. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  14. Matton, A.P.M.; de Vries, Y.; Burlage, L.C.; van Rijn, R.; Fujiyoshi, M.; de Meijer, V.E.; de Boer, M.T.; de Kleine, R.H.J.; Verkade, H.J.; Gouw, A.S.H.; et al. Biliary Bicarbonate, pH, and Glucose are Suitable Biomarkers of Biliary Viability during Ex Situ Normothermic Machine Perfusion of Human Donor Livers. Transplantation 2019, 103, 1405–1413. [Google Scholar] [CrossRef] [Green Version]
  15. Op den Dries, S.; Karimian, N.; Sutton, M.; Westerkamp, A.; Nijsten, M.; Gouw, A.; Wiersema-Buist, J.; Lisman, T.; Leuvenink, H.; Porte, R. Ex Vivo Normothermic Machine Perfusion and Viability Testing of Discarded Human Donor Livers. Am. J. Transplant. 2013, 13, 1327–1335. [Google Scholar] [CrossRef]
  16. Gilbo, N.; Monbaliu, D. Temperature and Oxygenation during Organ Preservation: Friends or Foes? Curr. Opin. Organ. Transplant. 2017, 22, 290–299. [Google Scholar] [CrossRef]
  17. Boteon, Y.L.; Attard, J.; Boteon, A.P.; Wallace, L.; Reynolds, G.; Hubscher, S.; Mirza, D.F.; Mergental, H.; Bhogal, R.H.; Afford, S.C. Manipulation of Lipid Metabolism during Normothermic Machine Perfusion: Effect of Defatting Therapies on Donor Liver Functional Recovery. Liver Transplant. 2019, 25, 1007–1022. [Google Scholar] [CrossRef] [Green Version]
  18. De Vries, R.J.; Tessier, S.N.; Banik, P.D.; Nagpal, S.; Cronin, S.E.; Ozer, S.; Hafiz, E.O.; van Gulik, T.M.; Yarmush, M.L.; Markmann, J.F. Subzero Non-Frozen Preservation of Human Livers in the Supercooled State. Nat. Protoc. 2020, 15, 1–17. [Google Scholar] [CrossRef]
  19. Thorne, A.M.; Ubbink, R.; Brüggenwirth, I.M.; Nijsten, M.W.; Porte, R.J.; de Meijer, V.E. Hyperthermia Induced Changes in Liver Physiology and Metabolism: A Rationale for Hyperthermic Machine Perfusion. Am. J. Physiol. Gastrointest. Liver Physiol. 2020, 319, G43–G50. [Google Scholar] [CrossRef]
  20. Plaats, A.V.D. The Groningen Hypothermic Liver Perfusion System for Improved Preservation in Organ Transplantation. Diss. Print 2005, 34, 1924–1934. [Google Scholar]
  21. Karimian, N.; Matton, A.P.; Westerkamp, A.C.; Burlage, L.C.; Op den Dries, S.; Leuvenink, H.G.; Lisman, T.; Uygun, K.; Markmann, J.F.; Porte, R.J. Ex Situ Normothermic Machine Perfusion of Donor Livers. JoVE (J. Vis. Exp.) 2015, 99, e52688. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  22. Eshmuminov, D.; Leoni, F.; Schneider, M.A.; Becker, D.; Muller, X.; Onder, C.; Hefti, M.; Schuler, M.J.; Dutkowski, P.; Graf, R. Perfusion Settings and Additives in Liver Normothermic Machine Perfusion with Red Blood Cells as Oxygen Carrier. A Systematic Review of Human and Porcine Perfusion Protocols. Transplant. Int. 2018, 31, 956–969. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  23. Hall, J.E. Guyton and Hall Textbook of Medical Physiology, Jordanian Edition E-Book; Elsevier: Amsterdam, The Netherlands, 2016. [Google Scholar]
  24. Berg, J. Tymoczko, J.L.; Stryer, L. Biochemistry, Chapter 14. In Metabolism: Basic Concepts and Design, 5th ed.; W H Freeman: New York, NY, USA, 2002. [Google Scholar]
  25. Pittman, R.N. Regulation of Tissue Oxygenation. In Colloquium Series on Integrated Systems Physiology: From Molecule to Function; Morgan & Claypool Life Sciences: San Rafael, CA, USA, 2011; pp. 1–100. [Google Scholar]
  26. Nelson, D.L.; Lehninger, A.L.; Cox, M.M. Citric acid cycle. In Lehninger Principles of Biochemistry; W.H. Freeman: New York, NY, USA, 2005; p. 615. [Google Scholar]
  27. Blaxter, K. Energy Metabolism in Animals and Man; CUP Archive: Cambridge, UK, 1989. [Google Scholar]
  28. Gillooly, J.F.; Brown, J.H.; West, G.B.; Savage, V.M.; Charnov, E.L. Effects of Size and Temperature on Metabolic Rate. Science 2001, 293, 2248–2251. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  29. Schulte, P.M. The Effects of Temperature on Aerobic Metabolism: Towards a Mechanistic Understanding of the Responses of Ectotherms to a Changing Environment. J. Exp. Biol. 2015, 218, 1856–1866. [Google Scholar] [CrossRef] [Green Version]
  30. Siggaard-Andersen, O.; Wimberley, P.D.; Gothgen, I.; Siggaard-Andersen, M. A Mathematical Model of the Hemoglobin-Oxygen Dissociation Curve of Human Blood and of the Oxygen Partial Pressure as a Function of Temperature. Clin. Chem. 1984, 30, 1646–1651. [Google Scholar] [CrossRef]
  31. Lutz, J.; Henrich, H.; Bauereisen, E. Oxygen Supply and Uptake in the Liver and the Intestine. Pflügers Arch. 1975, 360, 7–15. [Google Scholar] [CrossRef]
  32. Rettich, T.R.; Battino, R.; Wilhelm, E. Solubility of Gases in Liquids. 22. High-Precision Determination of Henry’s Law Constants of Oxygen in Liquid Water from T = 274 K to T = 328 K. J. Chem. Thermodyn. 2000, 32, 1145–1156. [Google Scholar] [CrossRef]
  33. Avishay, D.M.; Tenny, K.M. Henry’s Law. In StatPearls; StatPearls Publishing LLC: Treasure Island, FL, USA, 2019. [Google Scholar]
  34. Schlegel, A.; De Rougemont, O.; Graf, R.; Clavien, P.; Dutkowski, P. Protective Mechanisms of End-Ischemic Cold Machine Perfusion in DCD Liver Grafts. J. Hepatol. 2013, 58, 278–286. [Google Scholar] [CrossRef]
  35. Westerkamp, A.C.; Mahboub, P.; Meyer, S.L.; Hottenrott, M.; Ottens, P.J.; Wiersema-Buist, J.; Gouw, A.S.H.; Lisman, T.; Leuvenink, H.G.D.; Porte, R.J. End-Ischemic Machine Perfusion Reduces Bile Duct Injury in Donation After Circulatory Death Rat Donor Livers Independent of the Machine Perfusion Temperature. Liver Transpl. 2015, 21, 1300–1311. [Google Scholar] [CrossRef] [Green Version]
  36. Monbaliu, D.; Vekemans, K.; De Vos, R.; Brassil, J.; Heedfeld, V.; Qiang, L.; D’ hollander, M.; Roskams, T.; Pirenne, J. Hemodynamic, Biochemical, and Morphological Characteristics during Preservation of Normal Porcine Livers by Hypothermic Machine Perfusion. In Transplantation Proceedings; Elsevier: Amsterdam, The Netherlands, 2007; Volume 39, pp. 2652–2658. [Google Scholar]
  37. Bral, M.; Gala-Lopez, B.; Thiesen, A.; Hatami, S.; Bigam, D.L.; Freed, D.M.; James Shapiro, A.M. Determination of Minimal Hemoglobin Level Necessary for Normothermic Porcine Ex Situ Liver Perfusion. Transplantation 2018, 102, 1284–1292. [Google Scholar] [CrossRef]
  38. Liu, Q.; Nassar, A.; Farias, K.; Buccini, L.; Mangino, M.J.; Baldwin, W.; Bennett, A.; O’Rourke, C.; Iuppa, G.; Soliman, B.G.; et al. Comparing Normothermic Machine Perfusion Preservation with Different Perfusates on Porcine Livers from Donors After Circulatory Death. Am. J. Transplant. 2016, 16, 794–807. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  39. Jahr, J.S.; Moallempour, M.; Lim, J.C. HBOC-201, Hemoglobin Glutamer-250 (Bovine), Hemopure® (Biopure Corporation). Expert Opin. Biol. Ther. 2008, 8, 1425–1433. [Google Scholar] [CrossRef] [PubMed]
  40. Taguchi, K.; Urata, Y.; Anraku, M.; Maruyama, T.; Watanabe, H.; Sakai, H.; Horinouchi, H.; Kobayashi, K.; Tsuchida, E.; Kai, T.; et al. Pharmacokinetic Study of Enclosed Hemoglobin and Outer Lipid Component After the Administration of Hemoglobin Vesicles as an Artificial Oxygen Carrier. Drug Metab. Dispos. 2009, 37, 1456–1463. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  41. Sakai, H.; Hamada, K.; Takeoka, S.; Nishide, H.; Tsuchida, E. Physical Properties of Hemoglobin Vesicles as Red Cell Substitutes. Biotechnol. Prog. 1996, 12, 119–125. [Google Scholar] [CrossRef]
  42. Alix, P.; Val-Laillet, D.; Turlin, B.; Mosbah, I.B.; Burel, A.; Bobillier, E.; Bendavid, C.; Delpy, E.; Zal, F.; Corlu, A. Adding the Oxygen Carrier M101 to a Cold-Storage Solution could be an Alternative to HOPE for Liver Graft Preservation. JHEP Rep. 2020, 2, 100119. [Google Scholar]
  43. Kaminski, J.; Hannaert, P.; Kasil, A.; Thuillier, R.; Leize, E.; Delpy, E.; Steichen, C.; Goujon, J.M.; Zal, F.; Hauet, T. Efficacy of the Natural Oxygen Transporter HEMO2 Life® in Cold Preservation in a Preclinical Porcine Model of Donation After Cardiac Death. Transpl. Int. 2019, 32, 985–996. [Google Scholar] [CrossRef]
  44. Menz, D.; Feltgen, N.; Menz, H.; Müller, B.; Lechner, T.; Dresp, J.; Hoerauf, H. How to Ward off Retinal Toxicity of Perfluorooctane and Other Perfluorocarbon Liquids? Invest. Ophthalmol. Vis. Sci. 2018, 59, 4841–4846. [Google Scholar] [CrossRef] [Green Version]
  45. Riess, J.G. Oxygen Carriers (“blood Substitutes”) Raison D’Être, Chemistry, and some Physiology Blut Ist Ein Ganz Besondrer Saft. Chem. Rev. 2001, 101, 2797–2920. [Google Scholar] [CrossRef]
  46. Marengo-Rowe, A.J. Structure-Function Relations of Human Hemoglobins. Bayl Univ. Med. Cent. Proc. 2006, 19, 239–245. [Google Scholar] [CrossRef]
  47. Lodemann, P.; Schorer, G.; Frey, B.M. Wrong Molar Hemoglobin Reference Values—a Longstanding Error that should be Corrected. Ann. Hematol. 2010, 89, 209. [Google Scholar] [CrossRef] [Green Version]
  48. Banan, B.; Watson, R.; Xu, M.; Lin, Y.; Chapman, W. Development of a Normothermic Extracorporeal Liver Perfusion System Toward Improving Viability and Function of Human Extended Criteria Donor Livers. Liver Transplant. 2016, 22, 979–993. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  49. Mergental, H.; Perera, M.; Laing, R.; Muiesan, P.; Isaac, J.; Smith, A.; Stephenson, B.; Cilliers, H.; Neil, D.; Hübscher, S. Transplantation of Declined Liver Allografts Following Normothermic Ex-situ Evaluation. Am. J. Transplant. 2016, 16, 3235–3245. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  50. Vogel, T.; Brockmann, J.G.; Quaglia, A.; Morovat, A.; Jassem, W.; Heaton, N.D.; Coussios, C.C.; Friend, P.J. The 24-hour Normothermic Machine Perfusion of Discarded Human Liver Grafts. Liver Transplant. 2017, 23, 207–220. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  51. Laing, R.W.; Bhogal, R.H.; Wallace, L.; Boteon, Y.; Neil, D.A.H.; Smith, A.; Stephenson, B.T.F.; Schlegel, A.; Hubscher, S.G.; Mirza, D.F.; et al. The use of an Acellular Oxygen Carrier in a Human Liver Model of Normothermic Machine Perfusion. Transplantation 2017, 101, 2746–2756. [Google Scholar] [CrossRef] [PubMed]
  52. Chen, J.; Scerbo, M.; Kramer, G. A Review of Blood Substitutes: Examining the History, Clinical Trial Results, and Ethics of Hemoglobin-Based Oxygen Carriers. Clinics 2009, 64, 803–813. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  53. Fontes, P.; Lopez, R.; van der Plaats, A.; Vodovotz, Y.; Minervini, M.; Scott, V.; Soltys, K.; Shiva, S.; Paranjpe, S.; Sadowsky, D.; et al. Liver Preservation with Machine Perfusion and a Newly Developed Cell-Free Oxygen Carrier Solution Under Subnormothermic Conditions. Am. J. Transplant. 2015, 15, 381–394. [Google Scholar] [CrossRef]
  54. Sadowsky, D.; Zamora, R.; Barclay, D.; Yin, J.; Fontes, P.; Vodovotz, Y. Machine Perfusion of Porcine Livers with Oxygen-Carrying Solution Results in Reprogramming of Dynamic Inflammation Networks. Front. Pharmacol. 2016, 7, 413. [Google Scholar] [CrossRef] [Green Version]
  55. Matton, A.P.; Burlage, L.C.; van Rijn, R.; de Vries, Y.; Karangwa, S.A.; Nijsten, M.W.; Gouw, A.S.; Wiersema-Buist, J.; Adelmeijer, J.; Westerkamp, A.C. Normothermic Machine Perfusion of Donor Livers without the Need for Human Blood Products. Liver Transplant. 2018, 24, 528–538. [Google Scholar] [CrossRef]
  56. Boteon, Y.L.; Boteon, A.P.; Attard, J.; Mergental, H.; Mirza, D.F.; Bhogal, R.H.; Afford, S.C. Ex Situ Machine Perfusion as a Tool to Recondition Steatotic Donor Livers: Troublesome Features of Fatty Livers and the Role of Defatting Therapies. A Systematic Review. Am. J. Transplant. 2018, 18, 2384–2399. [Google Scholar] [CrossRef] [Green Version]
  57. De Vries, Y.; van Leeuwen, O.B.; Matton, A.P.M.; Fujiyoshi, M.; de Meijer, V.E.; Porte, R.J. Ex Situ Normothermic Machine Perfusion of Donor Livers using a Haemoglobin-Based Oxygen Carrier: A Viable Alternative to Red Blood Cells. Transpl. Int. 2018, 31, 1281–1282. [Google Scholar] [CrossRef] [Green Version]
  58. Aburawi, M.M.; Fontan, F.M.; Karimian, N.; Eymard, C.; Cronin, S.; Pendexter, C.; Nagpal, S.; Banik, P.; Ozer, S.; Mahboub, P. Synthetic Hemoglobin-based Oxygen Carriers are an Acceptable Alternative for Packed Red Blood Cells in Normothermic Kidney Perfusion. Am. J. Transplant. 2019, 19, 2814–2824. [Google Scholar] [CrossRef] [PubMed]
  59. Vrselja, Z.; Daniele, S.G.; Silbereis, J.; Talpo, F.; Morozov, Y.M.; Sousa, A.M.; Tanaka, B.S.; Skarica, M.; Pletikos, M.; Kaur, N. Restoration of Brain Circulation and Cellular Functions Hours Post-Mortem. Nature 2019, 568, 336. [Google Scholar] [CrossRef] [PubMed]
  60. Van Leeuwen, O.B.; de Vries, Y.; Fujiyoshi, M.; Nijsten, M.W.N.; Ubbink, R.; Pelgrim, G.J.; Werner, M.J.M.; Reyntjens, K.M.E.M.; van den Berg, A.P.; de Boer, M.T.; et al. Transplantation of High-Risk Donor Livers After Ex Situ Resuscitation and Assessment using Combined Hypo- and Normothermic Machine Perfusion: A Prospective Clinical Trial. Ann. Surg. 2019, 270, 906–914. [Google Scholar] [CrossRef] [PubMed]
  61. Bhattacharjee, R.N.; Patel, S.V.B.; Sun, Q.; Jiang, L.; Richard-Mohamed, M.; Ruthirakanthan, A.; Aquil, S.; Al-Ogaili, R.; Juriasingani, S.; Sener, A.; et al. Renal Protection Against Ischemia Reperfusion Injury: Hemoglobin-Based Oxygen Carrier-201 Versus Blood as an Oxygen Carrier in Ex Vivo Subnormothermic Machine Perfusion. Transplantation 2020, 104, 482–489. [Google Scholar] [CrossRef] [PubMed]
  62. Shonaka, T.; Matsuno, N.; Obara, H.; Yoshikawa, R.; Nishikawa, Y.; Gouchi, M.; Otani, M.; Takahashi, H.; Azuma, H.; Sakai, H.; et al. Application of Perfusate with Human-Derived Oxygen Carrier Solution Under Subnormothermic Machine Perfusion for Donation After Cardiac Death Liver Grafts in Pigs. Transplant. Proc. 2018, 50, 2821–2825. [Google Scholar] [CrossRef] [PubMed]
  63. Shonaka, T.; Matsuno, N.; Obara, H.; Yoshikawa, R.; Nishikawa, Y.; Ishihara, Y.; Bochimoto, H.; Gochi, M.; Otani, M.; Kanazawa, H. Impact of Human-Derived Hemoglobin Based Oxygen Vesicles as a Machine Perfusion Solution for Liver Donation After Cardiac Death in a Pig Model. PLoS ONE 2019, 14, e0226183. [Google Scholar] [CrossRef] [Green Version]
  64. Brasile, L.; DelVecchio, P.; Amyot, K.; Haisch, C.; Clarke, J. Organ Preservation without Extreme Hypothermia using an Oxygent™ Supplemented Perfusate. Artif. Cells Blood Substit. Biotechnol. 1994, 22, 1463–1468. [Google Scholar] [CrossRef]
  65. Inci, I.; Arni, S.; Iskender, I.; Citak, N.; Rodriguez, J.M.; Weisskopf, M.; Opitz, I.; Weder, W.; Frauenfelder, T.; Krafft, M.P. Functional, Metabolic and Morphologic Results of Ex Vivo Donor Lung Perfusion with a Perfluorocarbon-Based Oxygen Carrier Nanoemulsion in a Large Animal Transplantation Model. Cells 2020, 9, 2501. [Google Scholar] [CrossRef]
  66. Kohno, M.; Ikeda, T.; Hashimoto, R.; Izumi, Y.; Watanabe, M.; Horinouchi, H.; Sakai, H.; Kobayashi, K.; Iwazaki, M. Acute 40% Exchange-Transfusion with Hemoglobin-Vesicles in a Mouse Pneumonectomy Model. PLoS ONE 2017, 12, e0178724. [Google Scholar] [CrossRef] [Green Version]
  67. Sakai, H. Overview of Potential Clinical Applications of Hemoglobin Vesicles (HbV) as Artificial Red Cells, Evidenced by Preclinical Studies of the Academic Research Consortium. J. Funct. Biomater. 2017, 8, 10. [Google Scholar] [CrossRef]
  68. Montagne, K.; Huang, H.; Ohara, K.; Matsumoto, K.; Mizuno, A.; Ohta, K.; Sakai, Y. Use of Liposome Encapsulated Hemoglobin as an Oxygen Carrier for Fetal and Adult Rat Liver Cell Culture. J. Biosci. Bioeng. 2011, 112, 485–490. [Google Scholar] [CrossRef] [PubMed]
  69. Araki, J.; Sakai, H.; Takeuchi, D.; Kagaya, Y.; Tashiro, K.; Naito, M.; Mihara, M.; Narushima, M.; Iida, T.; Koshima, I. Normothermic Preservation of the Rat Hind Limb with Artificial Oxygen-Carrying Hemoglobin Vesicles. Transplantation 2015, 99, 687–692. [Google Scholar] [CrossRef] [PubMed]
  70. Jahr, J.S.; Mackenzie, C.; Pearce, L.B.; Pitman, A.; Greenburg, A.G. HBOC-201 as an Alternative to Blood Transfusion: Efficacy and Safety Evaluation in a Multicenter Phase III Trial in Elective Orthopedic Surgery. J. Trauma Acute Care Surg. 2008, 64, 1484–1497. [Google Scholar] [CrossRef] [PubMed]
  71. Natanson, C.; Kern, S.J.; Lurie, P.; Banks, S.M.; Wolfe, S.M. Cell-Free Hemoglobin-Based Blood Substitutes and Risk of Myocardial Infarction and Death: A Meta-Analysis. JAMA 2008, 299, 2304–2312. [Google Scholar] [CrossRef] [PubMed]
  72. Taverne, Y.J.; de Wijs-Meijler, D.; te Lintel Hekkert, M.; Moon-Massat, P.F.; Dubé, G.P.; Duncker, D.J.; Merkus, D. Normalization of Hemoglobin-Based Oxygen Carrier-201 Induced Vasoconstriction: Targeting Nitric Oxide and Endothelin. J. Appl. Physiol. 2017, 122, 1227–1237. [Google Scholar] [CrossRef]
  73. Cabrales, P.; Friedman, J.M. HBOC Vasoactivity: Interplay between Nitric Oxide Scavenging and Capacity to Generate Bioactive Nitric Oxide Species. Antioxid. Redox Signal. 2013, 18, 2284–2297. [Google Scholar] [CrossRef]
  74. Dubé, G.P.; Pitman, A.N.; Mackenzie, C.F. Relative Efficacies of HBOC-201 and Polyheme to Increase Oxygen Transport Compared to Blood and Crystalloids. Shock 2019, 52, 100–107. [Google Scholar] [CrossRef]
  75. Mackenzie, C.F.; Dubé, G.P.; Pitman, A.; Zafirelis, M. Users Guide to Pitfalls and Lessons Learned about HBOC-201 during Clinical Trials, Expanded Access, and Clinical use in 1701 Patients. Shock 2019, 52, 92–99. [Google Scholar] [CrossRef]
  76. Mackenzie, C.F.; Pitman, A.N.; Hodgson, R.E.; Sussman, M.J.; Levien, L.J.; Jahr, J.S.; Greenburg, A.G. Are Hemoglobin-Based Oxygen Carriers being withheld because of Regulatory Requirement for Equivalence to Packed Red Blood Cells? Am. J. Ther. 2015, 22, e115–e121. [Google Scholar] [CrossRef]
  77. Mackenzie, C.F.; Moon-Massat, P.F.; Shander, A.; Javidroozi, M.; Greenburg, A.G. When Blood is Not an Option: Factors Affecting Survival After the use of a Hemoglobin-Based Oxygen Carrier in 54 Patients with Life-Threatening Anemia. Anesth. Analg. 2010, 110, 685–693. [Google Scholar] [CrossRef]
  78. Posluszny, J.A.; Napolitano, L.M. Hemoglobin-Based Oxygen Carrier for Traumatic Hemorrhagic Shock Treatment in a Jehovah’s Witness. Arch. Trauma. Res. 2016, 5, e30610. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  79. De Vries, Y.; Matton, A.P.; Nijsten, M.W.; Werner, M.J.; van den Berg, A.P.; de Boer, M.T.; Buis, C.I.; Fujiyoshi, M.; de Kleine, R.H.; van Leeuwen, O.B. Pretransplant Sequential Hypo-and Normothermic Machine Perfusion of Suboptimal Livers Donated After Circulatory Death using a Hemoglobin-based Oxygen Carrier Perfusion Solution. Am. J. Transplant. 2019, 19, 1202–1211. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  80. Linberg, R.; Conover, C.D.; Shum, K.L. Hemoglobin Based Oxygen Carriers: How Much Methemoglobin is Too Much? Artif. Cells Blood Substit. Biotechnol. 1998, 26, 133–148. [Google Scholar] [CrossRef] [PubMed]
  81. Rousselot, M.; Delpy, E.; Drieu La Rochelle, C.; Lagente, V.; Pirow, R.; Rees, J.; Hagege, A.; Le Guen, D.; Hourdez, S.; Zal, F. Arenicola Marina Extracellular Hemoglobin: A New Promising Blood Substitute. Biotechnol. J. Healthc. Nutr. Technol. 2006, 1, 333–345. [Google Scholar] [CrossRef] [PubMed]
  82. Thuillier, R.; Dutheil, D.; Trieu, M.; Mallet, V.; Allain, G.; Rousselot, M.; Denizot, M.; Goujon, J.; Zal, F.; Hauet, T. Supplementation with a New Therapeutic Oxygen Carrier Reduces Chronic Fibrosis and Organ Dysfunction in Kidney Static Preservation. Am. J. Transplant. 2011, 11, 1845–1860. [Google Scholar] [CrossRef] [PubMed]
  83. Brüggenwirth, I.M.; van Leeuwen, O.B.; Müller, M.; Dutkowski, P.; Monbaliu, D.; Martins, P.N.; Porte, R.J.; de Meijer, V.E. The Importance of Adequate Oxygenation during Hypothermic Machine Perfusion. JHEP Rep. 2020, 3, 100194. [Google Scholar] [CrossRef]
  84. Kasil, A.; Giraud, S.; Couturier, P.; Amiri, A.; Danion, J.; Donatini, G.; Matillon, X.; Hauet, T.; Badet, L. Individual and Combined Impact of Oxygen and Oxygen Transporter Supplementation during Kidney Machine Preservation in a Porcine Preclinical Kidney Transplantation Model. Int. J. Mol. Sci. 2019, 20, 1992. [Google Scholar] [CrossRef] [Green Version]
  85. Hosgood, S.A.; Nicholson, M.L. The Role of Perfluorocarbon in Organ Preservation. Transplantation 2010, 89, 1169–1175. [Google Scholar] [CrossRef]
  86. Martins, P.N.; Berendsen, T.A.; Yeh, H.; Bruinsma, B.G.; Izamis, M.; Den Dries, S.O.; Gillooly, A.R.; Porte, R.; Yarmush, M.L.; Uygun, K. Oxygenated UW Solution Decreases ATP Decay and Improves Survival After Transplantation of DCD Liver Grafts. Transplantation 2019, 103, 363–370. [Google Scholar] [CrossRef] [Green Version]
Figure 1. Graphical presentation of the relation between partial oxygen (PO2) pressure and the O2 content of different solutions. Note how poorly O2 dissolves in water (blue curve). To achieve a useful O2 content without an oxygen carrier, a saturation of 100% O2 is required, i.e., a partial pressure of 760 mm Hg. Perfluorocarbons (PFC; yellow curve) can dissolve 20 times more O2. The red blood cell (RBC) and hemoglobin-based oxygen carrier-201 (HBOC-201) curves assume a concentration equivalent with 7.76 mmol/L of O2 binding places [30]. Additionally, note that the only small apparent shifts in the dissociation curves result from the supraphysiological PO2 of 760 mmHg.
Figure 1. Graphical presentation of the relation between partial oxygen (PO2) pressure and the O2 content of different solutions. Note how poorly O2 dissolves in water (blue curve). To achieve a useful O2 content without an oxygen carrier, a saturation of 100% O2 is required, i.e., a partial pressure of 760 mm Hg. Perfluorocarbons (PFC; yellow curve) can dissolve 20 times more O2. The red blood cell (RBC) and hemoglobin-based oxygen carrier-201 (HBOC-201) curves assume a concentration equivalent with 7.76 mmol/L of O2 binding places [30]. Additionally, note that the only small apparent shifts in the dissociation curves result from the supraphysiological PO2 of 760 mmHg.
Ijms 22 00235 g001
Figure 2. Graphical presentation of the relation between perfusion temperature and oxygen (O2) consumption (green curve) and O2 delivery. Metabolic rate and O2 consumption rise with approximately 10% for each increase in temperature measured in degrees Celsius. Note that the amount of O2 that is dissolved in water (blue curve) decreases at higher temperatures. At body temperature, O2 consumption/requirement will be larger than the amount that can be delivered by dissolved O2 alone, as indicated by the crossing green and blue curves. The addition of an oxygen carrier such as red blood cells (RBC) or hemoglobin-based oxygen carrier 201 (HBOC-201; red curve) can dramatically increase O2 content and delivery. Note that, as in whole body physiology, during organ perfusion oxygen delivery must be considerably higher than oxygen consumption, because oxygen consuming tissues such as the liver [31] can only extract a fraction of the delivered oxygen. The numbers displayed here assume oxygenation with 100% oxygen, a hemoglobin or HBOC-201 concentration equivalent to 7.76 mmol/L of O2-binding sites and a perfusion flow of 2300 mL/min.
Figure 2. Graphical presentation of the relation between perfusion temperature and oxygen (O2) consumption (green curve) and O2 delivery. Metabolic rate and O2 consumption rise with approximately 10% for each increase in temperature measured in degrees Celsius. Note that the amount of O2 that is dissolved in water (blue curve) decreases at higher temperatures. At body temperature, O2 consumption/requirement will be larger than the amount that can be delivered by dissolved O2 alone, as indicated by the crossing green and blue curves. The addition of an oxygen carrier such as red blood cells (RBC) or hemoglobin-based oxygen carrier 201 (HBOC-201; red curve) can dramatically increase O2 content and delivery. Note that, as in whole body physiology, during organ perfusion oxygen delivery must be considerably higher than oxygen consumption, because oxygen consuming tissues such as the liver [31] can only extract a fraction of the delivered oxygen. The numbers displayed here assume oxygenation with 100% oxygen, a hemoglobin or HBOC-201 concentration equivalent to 7.76 mmol/L of O2-binding sites and a perfusion flow of 2300 mL/min.
Ijms 22 00235 g002
Figure 3. Visualizing the large differences in size between various oxygen carriers: red blood cells (RBC), hemoglobin vesicles (Hb-Vs), hemoglobin-based oxygen carrier 201 (HBOC-201), human hemoglobin (Hb).
Figure 3. Visualizing the large differences in size between various oxygen carriers: red blood cells (RBC), hemoglobin vesicles (Hb-Vs), hemoglobin-based oxygen carrier 201 (HBOC-201), human hemoglobin (Hb).
Ijms 22 00235 g003
Table 1. Overview of the advantages and disadvantages of different oxygen carriers.
Table 1. Overview of the advantages and disadvantages of different oxygen carriers.
Oxygen CarrierAdvantagesDisadvantagesPharmacokineticsPossible Toxicity in Humans
Hemoglobin in red blood cells (RBC)Within its physiological microenvironment
Human blood product
Low methemoglobin production
Dynamic shift of O2-hemoglobin dissociation curve
Immune-mediated phenomena
Blood-borne infection transmission
RBC hemolysis during hypothermic machine perfusion (HMP)
Cross- matching difficulties
Precious resource
T ½ = 115 days
MW = 64 kDa
[Hb] = 12–15 g/dL
P50 = 27 mm Hg
ABO incompatibility
Hemoglobin-based oxygen carrier-201
Easy O2 release to tissue Sterile and pyrogen-free
Large temperature range (4 °C–37 °C)
Less viscous than RBC
Long shelf life: three years
Compatible with all blood types
Formation of methemoglobin
Short half-life
Systemic vasoconstriction
Lower O2 affinity than RBC
T ½ = 20 h
MW = ~250 kDa
[Hb] = 13 g/dL
P50 = 38–40 mm Hg
Systemic vasoconstriction
Hemoglobin vesicles
Absence of RBC antigens
Smaller than RBC
sDo not generate colloid osmotic pressure
Do not rupture
Long shelf life: two years
Only used in animal modelsT ½ = 2–3 days
[Hb] 10 g/dL
P50 = 9 mm Hg
Release of free Hb can cause renal toxicity
Hemarina M101
Preliminary evidence in static cold storage
Large temperature range (4 °C–37 °C)
Simple gradient release O2
High O2 affinity
Only used in preclinical HMP and clinically in static cold storageMW = 3600 kDa
P50 = 7 mm Hg
None reported
High O2 solubility
Obey Henry’s law
O2 uptake and release insensitive to environment
Formulated as emulsion, which reduces O2 content
Needs high PO2 to maximize O2 content
T ½ = 8–24 h
Emulsion dependent
Visual loss
WaterDelivers sufficient O2 below 20 °C
O2 content decreases with higher temperature leading to a mismatch above 20 °CT ½ = ∞
MW = 18 Da
MW = molecular weight, T ½ = half-life, [Hb] = concentration of Hb or its equivalent for other carriers, P50 = O2 tension where 50% of Hb is saturated with O2.
Table 2. Overview of ex situ (sub)normothermic machine perfusion using artificial oxygen carriers.
Table 2. Overview of ex situ (sub)normothermic machine perfusion using artificial oxygen carriers.
Author and YearOxygen CarrierTemperature RangeMachineSample Size
Species and Organ
Fontes et al. [53]
AJT 2015
HBOC-201SNMPLiver Assist66Porcine livers
Sadowsky et al. [54]
Front Pharmacol 2016
HBOC-201SNMPLiver Assist66Porcine livers
Matton et al. [55]
Liver Transpl 2018
HBOC-201NMPLiver Assist24-Human livers
Laing et al. [51]
Transplantation 2017
HBOC-201NMPLiver Assist5-Human livers
Boteon et al. [56]
AJT 2018
HBOC-201NMPLiver Assist10-Human livers
De Vries et al. [57]
AJT 2019
HBOC-201HMP to NMPLiver Assist75Human livers
Aburawi et al. [58]
AJT 2019
HBOC-201NMPKidney Assist7-Human kidneys
Vrselja et al. [59]
Nature 2019
HBOC-201NMP-32-Porcine brains
Van Leeuwen et al. [60]
Ann Surg 2019
HBOC-201HMP to NMPLiver Assist1611Human livers
Bhattacharjee et al. [61]
Transplantation 2020
HBOC-201SNMP-5-Porcine kidneys
Shonaka et al. [62]
Transplantation 2018
Hb-VsSNMP-3-Porcine livers
Shonaka et al. [63]
Plos one 2019
Hb-VsSNMP-5-Porcine livers
Brasile et al. [64]
Biotechnol. 1994
PFCSNMP-4-Canine kidney
Inci et al. [65]
Cells 2020
PFCSNMP-114Porcine lungs
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Bodewes, S.B.; van Leeuwen, O.B.; Thorne, A.M.; Lascaris, B.; Ubbink, R.; Lisman, T.; Monbaliu, D.; De Meijer, V.E.; Nijsten, M.W.N.; Porte, R.J. Oxygen Transport during Ex Situ Machine Perfusion of Donor Livers Using Red Blood Cells or Artificial Oxygen Carriers. Int. J. Mol. Sci. 2021, 22, 235.

AMA Style

Bodewes SB, van Leeuwen OB, Thorne AM, Lascaris B, Ubbink R, Lisman T, Monbaliu D, De Meijer VE, Nijsten MWN, Porte RJ. Oxygen Transport during Ex Situ Machine Perfusion of Donor Livers Using Red Blood Cells or Artificial Oxygen Carriers. International Journal of Molecular Sciences. 2021; 22(1):235.

Chicago/Turabian Style

Bodewes, Silke B., Otto B. van Leeuwen, Adam M. Thorne, Bianca Lascaris, Rinse Ubbink, Ton Lisman, Diethard Monbaliu, Vincent E. De Meijer, Maarten W. N. Nijsten, and Robert J. Porte. 2021. "Oxygen Transport during Ex Situ Machine Perfusion of Donor Livers Using Red Blood Cells or Artificial Oxygen Carriers" International Journal of Molecular Sciences 22, no. 1: 235.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop