Methods of administering nitric oxide to arterial or arterialized blood

The present invention provides methods of administering nitric oxide (NO) to a patient, the method comprising delivering nitric oxide-containing gas directly into arterial or arterialized blood. The methods of the present invention may be used in the treatment or prevention of a variety of diseases and disorders responsive to nitric oxide, including those resulting from ischemia or hypoxia.

TECHNICAL FIELD

Embodiments of the present invention generally relate to the field of methods and devices for therapeutic delivery of nitric oxide (NO) as well as stable pharmaceutical compositions comprising nitric oxide. The invention further relates to the use of such methods and devices to treat and protect cells and animals from injury, disease, and premature death.

BACKGROUND

The action of nitric oxide (NO) is considered regulatory in maintaining normal physiological homeostasis in humans and animals, i.e., host-defense, vascular tone, neurotransmission, bronchodilatation and inhibition of platelet function (see Giustarini et al., Clinica Chimica Acta (2003) 330:85-98). NO mediates blood pressure, learning and memory, immune responses, and inflammatory responses (see Thippeswamy et al., Histol. Histopathol. (2006) 21:445-458). In addition, the actions of NO have been observed in pathological conditions such as acute respiratory distress syndrome, hypertension, pulmonary hypertension, arthritis, arteriosclerosis, cancer, diabetes, some neurodegenerative diseases and stroke (see Giustarini et al., Clinica Chimica Acta (2003) 330:85-98).

Traditionally, inhaled NO (iNO) was believed to work exclusively in the lung due to inactivation by hemoglobin (Hb). That is, reaction with oxyhemoglobin to form methemoglobin and nitrate or heme iron nitrosyl hemoblogin (Hb) would cause a loss of vasodilating properties. However it has been found that a stable derivative is formed by a reaction resulting in nitrosylation of a conserved cysteine residue of the β subunit of Hb: S-nitrosylated-Hb (SNO-Hb). This reaction is favored in the presence of oxyhaemoglobin whereas binding of NO to the heme iron is favored in the deoxygenated state. See B. C. Creagh-Brown, et al. (2009)Critical Care13:212. In the past, remote or non-pulmonary effects of exogenously administered iNO were thought to be undesirable; however, it has recently been found that the stable derivative SNO-Hb retains vasodilatory properties and therefore could be beneficial for circulating targets.

There is clearly a need in the art for improved nitric oxide delivery, particularly systemic delivery that enables delivery of NO, via the circulatory system, to target tissues and organs outside of the pulmonary system.

SUMMARY

The present invention provides methods of administering an NO-containing gas directly to arterial or arterialized blood. These methods may be utilized for a variety of purposes and may be administered to various biological materials, including cells, tissues, organs, organisms, and animals, including humans and other mammals.

One aspect of the present invention provides a method for administering nitric oxide (NO) to a patient, the method comprising delivering an NO-containing gas directly to arterial or arterialized blood. In a specific embodiment delivery may be via a cardiopulmonary bypass (CPB) circuit, with the NO-containing gas being administered to arterialized blood after blood withdrawn from the patient has passed through the oxygenator of the CPB circuit, prior to infusion of the oxygenated (arterialized) blood into the patient.

Another aspect of the present invention provides methods for administering NO to a patient, the method comprising delivering NO-containing gas to arterialized blood in an extracorporeal membrane oxygenation (ECMO) circuit. The NO-containing gas may be administered into arterialized blood after blood has been oxygenated and CO2has been excreted out of the membrane oxygenator, including at any point after blood withdrawn from the patient has passed through the membrane oxygenator of the ECMO circuit, prior to infusion of the oxygenated (arterialized) blood into the patient. In ECMO, arterialized blood into which NO-containing gas is delivered may be returned either to the arterial or venous circulation of the patient.

Another aspect of the invention provides methods for delivery of NO-containing gas directly into arterial blood by injection, catheterization, infusion, or continuous infusion thereof into an arterial blood that is extracorporeal and then reinfusion of that blood into either an artery or vein of a patient. In particular embodiments of methods of the present invention, administering or contacting is performed by intra-arterial injection or infusion of NO-containing gas.

In certain embodiments, the NO-containing gas is administered as a bolus. Other embodiments provide that the NO-containing gas is administered continuously or in a pulsatile fashion.

In certain embodiments, the delivery concentration of NO in the NO-containing gas is in the range of about 0.1-500 ppm.

In some embodiments, the delivery concentration of NO in the NO-containing gas is in the range of 1-100 ppm.

In a particular embodiment, the delivery concentration of NO in the NO-containing gas is in the range of 2-20 ppm.

In a particular embodiment, the delivery concentration of NO in the NO-containing gas is in the range of 5-40 ppm.

In a particular embodiment, the delivery concentration of NO in the NO-containing gas is in the range of 10-30 ppm.

In a particular embodiment, the delivery concentration of NO in the NO-containing gas is the containing gas is in the range of 15-25 ppm.

In a particular embodiment, the delivery concentration of NO in the NO-containing gas is 20 ppm.

In certain embodiments, the NO-containing gas for administration may be generated locally (bed-side) for immediate delivery to a patient, for example as a component of an extracorporeal oxygenation apparatus. Local generation of NO gas for immediate delivery to a patient may be accomplished by reaction of a nitrite salt, such as sodium nitrite, and a reductant, such as ascorbic acid or maleic acid, in the presence of water, or generation of NO from room air, or other potential means. The NO gas so-produced is then delivered or introduced directly into the arterial or arterialized blood of the patient. Suitable devices for such local generation and delivery are known in the art (e.g., US 2007/0190184). In an alternative embodiment, preformed NO-containing gas is administered from a gas cylinder directly into the arterial or arterialized blood of the patient.

In a particular embodiment, the NO-containing gas is administered via a device, for example an ECMO device. The NO-containing gas may be administered within the oxygenation compartment of the device, wherein the oxygenation compartment contains two components. The first component is a first gas exchange membrane (also referred to as a membrane oxygenator) which exchanges oxygen for CO2in blood to produce arterialized blood. The second component is a second gas exchange membrane which exchanges NO for O2in the arterialized blood. The first and second components can be either structurally separate components in fluid communication or combined as one structure containing separate reaction areas within the oxygenation compartment. In either case, the second component is down-stream of the first component, as defined by the direction of blood flow in the device. Thus, NO-containing gas is administered either into the oxygenation compartment after O2has been administered into the oxygenation compartment and after CO2has been released, or NO is administered downstream of the oxygenation compartment (after blood has left the oxygenator but before it is delivered back into the patient) or both.

In a related embodiment, the present invention includes a method of treating or preventing a disease, disorder, or condition that benefits from treatment with NO comprising administering to a patient an amount of NO-containing gas effective to treat such disease, disorder, or condition, wherein the NO-containing gas is administered directly into arterial or arterialized blood. In particular embodiments, the disease, disorder or condition is a respiratory, cardiovascular, pulmonary, or blood disease or disorder, or a tumor, an infection, inflammation, shock, sepsis, or stroke, in a patient.

In a further embodiment, the present invention provides a method of preventing or reducing injury to, or enhancing survivability of, a biological material exposed to ischemic, hypoxic, or injured conditions, comprising contacting the biological material with an effective amount NO via administration of an NO-containing gas directly into arterial or arterialized blood.

In one embodiment, a biological material is contacted with the NO-containing gas via administration into arterial or arterialized blood before onset of the disease, disorder or condition that benefits therefrom. In another embodiment, the biological material is contacted with the NO-containing gas via administration into arterial or arterialized blood during occurrence of the disease, disorder or condition.

The present invention further provides systems and devices for the administration of NO-containing gas directly into arterial or arterialized blood.

DETAILED DESCRIPTION OF THE INVENTION

The term “arterialized blood” refers to venous blood which has been converted to arterial blood by absorption of oxygen and excretion of CO2Such conversion may be accomplished in vivo (e.g., by absorption of oxygen in the lungs) or ex vivo (e.g., by extracorporeal oxygenation).

The term “arterial blood” refers to oxygenated blood in the arterial circulation of the body.

The term “biological material” refers to any living biological material, including cells, tissues, organs, and/or organisms. It is contemplated that the methods of the present invention may be practiced on a part of an organism (such as in cells, in tissue, and/or in one or more organs), or on the whole organism. The term “in vivo biological material” refers to biological material that is in vivo, i.e., still within or attached to an organism.

“Therapeutically effective amount” refers to that amount of NO gas that, when administered via arterial or arterialized blood to a subject, preferably a human, is sufficient to effect treatment as defined herein. The amount of a compound of the invention which constitutes a “therapeutically effective amount” will vary depending on the compound, the condition and its severity, and the manner of administration, but can be determined routinely by one of ordinary skill in the art having regard to his own knowledge and to this disclosure.

“Treating” or “treatment” as used herein covers the treatment of the disease or condition of interest in a subject, preferably a human, having the disease or condition of interest, and includes: (i) preventing the disease or condition from occurring in the subject, (ii) inhibiting the disease or condition, i.e., arresting its progression; (iii) relieving the disease or condition, i.e., causing regression of the disease or condition; or (iv) relieving the symptoms resulting from the disease or condition. As used herein, the terms “disease,” “disorder,” and “condition” may be used interchangeably.

“Delivery concentration” refers to the concentration of NO gas in a composition of NO-containing gas for medical use which is delivered to arterial or arterialized blood. In addition to NO gas, such compositions for medical use may further comprise an inert diluent gas. It is to be understood that the delivery concentration will be diluted upon contact with blood, where it is mixed and distributed to the target biological material.

Prior to the present invention, NO was thought to react with oxyhemoglobin to form methemoglobin and nitrate or heme iron nitrosyl Hb, and thereby lose all vasodilating properties. However, it has been found that a stable derivate that retains vasodilatory properties is formed by a reaction resulting in nitrosylation of a conserved cysteine residue of the β subunit of Hb: S-nitrosylated-Hb (SNO-Hb). This reaction is favored in the presence of oxyhemoglobin whereas the prior reaction is favored in the deoxygenated state. Thus the present invention provides methods that maximize the formation of SNOHb, thereby maximizing the systemic effects of NO.

One aspect of the current invention relates to a method of delivering nitric oxide (NO) to a patient comprising administering NO-containing gas directly into arterial or arterialized blood, the administered gas having a delivery concentration of 0.01 to 10 ppm NO. In certain embodiments, the delivery concentration is in the range of 10 to 40 ppm. According to one or more embodiments, the delivery concentration is in the range of 40 to 100 ppm. In other embodiments, the delivery concentration is greater than 100 ppm.

In one embodiment, the NO-containing gas is administered continuously, for example by continuous infusion.

In another embodiment, the NO-containing gas is delivered as a bolus rather than via a continuous administration method. A “bolus” refers to a single administration delivered over a short period of time, for example by injection from a syringe. Multiple bolus administrations may be given to the subject, each separated by a period of time.

In another embodiment, the NO-containing gas is delivered in a pulse as opposed to continuous administration. A “pulse” refers to multiple short administrations within a time period.

In an additional embodiment, a device can monitor the arterial or arterialized blood and administer the NO-containing gas at any delivery rate or concentration as necessary to provide sufficient results. Administration can automatically or manually adjust or otherwise change the flow, concentration or amount of NO during the course of delivery.

The present invention includes improved methods of systemically treating diseases and disorders with nitric oxide, which comprise administering nitric oxide gas directly into arterial or arterialized blood. Further, the present invention provides improved methods of enhancing cell survival, inducing stasis, or protecting cells or tissue from injury due to hypoxia or ischemia, which comprise administering NO-containing gas directly to arterial or arterialized blood. The invention further includes methods and devices for the preparation and administration of NO-containing gas to a subject via arterial or arterialized blood. Without wishing to be bound by any particular theory, it may be that administration of NO gas directly to oxygenated blood (e.g., after blood passes through an extracorporeal oxygenation system) or directly through an arterial catheter or intra-arterial injection will maximize the formation of SNO-Hb and thus maximize the systemic effects.

In certain embodiments, methods, compositions, and devices of the present invention are used to systemically treat or prevent any of a variety of diseases and disorders that benefit from treatment with nitric oxide. In particular embodiments, the methods of the present invention may be used to modulate biological pathways regulated or affected by nitric oxide.

Nitric oxide mediates blood pressure (causing vasodilation), learning and memory, immune responses and inflammatory responses. Accordingly, diseases, disorders or conditions potentially treatable by systemic administration of NO gas directly into arterial or arterialized blood according to the invention include respiratory, cardiovascular, pulmonary, and blood diseases, disorders or conditions, as well as hypoxemia, tumors, infections, inflammation, shock, sepsis and stroke. In specific examples, respiratory distress syndrome, asthma, bronchospastic disease, myocardial infarction, hemorrhage, sickle cell disease, platelet aggregation and major surgery may be treatable according to the methods of the invention. Further specific examples include pulmonary hypertension and hypoxemia following cardiopulmonary bypass, mitral valve replacement, heart or lung transplantation, and pulmonary embolism.

Systemic administration of nitric oxide gas into arterial or arterialized blood may be useful in suppressing, killing, and inhibiting pathogenic cells, such as tumor cells, cancer cells, or microorganisms, including but not limited to pathogenic bacteria, pathogenic mycobacteria, pathogenic parasites, and pathogenic fungi. Examples of microorganisms include those associated with a respiratory infection within the respiratory tract.

Systemic administration of nitric oxide gas into arterial or arterialized blood may enhance the survivability of biological materials, including, e.g., organs and tissues, that are subjected to ischemic or hypoxic conditions. In related embodiments, the present invention provides methods of preventing or reducing damage to biological materials, including, e.g., including cell, organ or tissue injuries resulting from ischemia or hypoxia. It is understood that a whole biological material or only a portion thereof, e.g., a particular organ, may be subjected to ischemic or hypoxic conditions.

The ischemic or hypoxic conditions may be the result of an injury or disease suffered by an organism. Examples of specific diseases that can induce ischemia or hypoxia include, but are not limited to, traumatic injury or surgery, respiratory or cardiac arrest, tumors, heart diseases, and neurological diseases. Examples of specific injuries that can result in ischemic or hypoxic conditions include, but are not limited to, external insults, such as burns, cutting wounds, amputations, gunshot wounds, or surgical trauma. In addition, injuries can also include internal insults, such as stroke or heart attack, which result in the acute reduction in circulation. Other injuries include reductions in circulation due to non-invasive stress, such as exposure to cold or radiation, or a planned reduction in circulation, e.g., during heart surgery.

In certain embodiments, methods of the present invention include systemically administering NO-containing gas directly into arterial or arterialized blood prior to development of a disease, disorder or condition treatable with NO gas, e.g., prior to an ischemic or hypoxic injury or disease insult. Examples of such situations include, but are not limited to, major surgery where blood loss may occur spontaneously or as a result of a procedure, cardiopulmonary bypass in which oxygenation of the blood may be compromised or in which vascular delivery of blood may be reduced (as in the setting of coronary artery bypass graft (CABG) surgery), or in the treatment of organ donors prior to removal of donor organs for transport and transplantation into a recipient. Other examples include, but are not limited to, medical conditions in which a risk of injury or disease progression is inherent (e.g., in the context of unstable angina, following angioplasty, bleeding aneurysms, hemorrhagic strokes, following major trauma or blood loss).

In certain embodiments, methods of the present invention include systemically administering NO-containing gas directly into arterial or arterialized blood after development or onset of a disease, disorder or condition treatable with NO, e.g., after an ischemic or hypoxic injury or disease insult, or after onset any of the diseases, disorders or conditions discussed above. In a particular aspect of such embodiments, NO-containing gas may be administered to a patient suffering from the disease, disorder or condition upon recognition or diagnosis of the disease, disorder or condition.

In certain embodiments, inflammatory-related diseases or disorders may be treated by administration of NO-containing gas directly into arterial or arterialized blood. Inflammatory-related diseases or disorders which may be treatable by the methods of the present invention include, e.g., multiple sclerosis, arthritis, rheumatoid arthritis, systemic lupus erythematosus, graft versus host disease, diabetes, psoriasis, progressive systemic sclerosis, scleroderma, acute coronary syndrome, Crohn's Disease, endometriosis, glomerulonephritis, myasthenia gravis, idiopathic pulmonary fibrosis, asthma, acute respiratory distress syndrome (ARDS), vasculitis, and inflammatory autoimmune myositis.

In a specific embodiment, the methods of the invention comprise administration of NO-containing gas directly into arterialized blood in an extracorporeal oxygenation system. The extracorporeal oxygenation system may be, for example, an extracorporeal membrane oxygenation system or a CPB circuit. In such methods the NO-containing gas is administered into the blood at any point in the system which is after oxygenation of the withdrawn blood. An example of CPB system20according to the invention is illustrated inFIG. 1. Venous blood is withdrawn from the patient through venous cannula20, which may be inserted in the right atrium, vena cava or femoral vein. Withdrawn venous blood is collected in reservoir11and circulated into oxygenator13by pump12, where it is oxygenated and typically cooled by heat exchanger14to slow the body's basal metabolism during bypass surgery. The oxygenated blood is generally filtered through filter15prior to return to the body via arterial cannula16, which may be inserted in the ascending aorta or the femoral artery. NO-containing gas may be introduced into the CBP circuit via NO delivery device18which is and in fluid communication with NO generating device/NO reservoir17and with CBP system20downstream of oxygenator13. NO-containing gas may be introduced into the CBP circuit at any point after oxygenator13for return to the arterial circulation. In the CBP circuit illustrated inFIG. 1, this includes introduction between oxygenator13and filter15(as shown) or between filter15and arterial cannula16(not shown). Alternatively, NO-containing gas may be introduced into the CBP circuit in oxygenator13, provided blood is oxygenated prior to contact with the NO-containing gas within oxygenator13.

In a further aspect, the invention provides extracorporeal oxygenation systems which comprise a component for introduction of NO-containing gas into oxygenated (arterialized) blood prior to infusion into the body of a patient. Such structure of such apparati are generally as described above, with the addition of a device for introduction of NO-containing gas into the portion of the circuit which contains arterialized blood. The device for introduction of NO-containing gas into oxygenated blood prior to infusion may comprise a container, gas cylinder or receptacle for holding or locally generating the NO-containing gas, referred to as an “NO generator/receptacle”. The device for introduction of the NO-containing gas into the arterialized blood will typically include a pump, injector or metering device to facilitate delivery of the NO-containing gas into the oxygenated blood of the extracorporeal circuit for return to the patient, referred to as an “NO delivery device”.

Extracorporeal oxygenation systems are simplified CBP circuits which provide cardiac and respiratory support oxygen to patients. In these systems venous blood is withdrawn from the patient, oxygenated outside of the body, and returned either via the arterial system or the venous system. A typical extracorporeal oxygenation system uses a membrane oxygenator and is referred to as an extracorporeal membrane oxygenation (ECMO) system. The system comprises a venous cannula typically placed in the right common femoral vein for extraction and an arterial cannula placed either into the right femoral artery (veno-arterial ECMO) or the right internal jugular vein (veno-venous ECMO) for infusion. In the methods of the invention, to obtain direct administration of NO-containing gas into arterialized blood, the NO-containing gas is introduced into the withdrawn blood at any point between the oxygenator and the venous or arterial infusion cannula. Alternatively, NO-containing gas may be introduced into the withdrawn blood in the oxygenator, provided blood is oxygenated prior to contact with the NO-containing gas within the oxygenator.

In a particular embodiment, the NO-containing gas is administered via a device, for example an ECMO device. The NO-containing gas may be administered within the oxygenation compartment of the device, wherein the oxygenation compartment contains two components. The first component is a first gas exchange membrane (also referred to as a membrane oxygenator) which exchanges oxygen for CO2in blood to produce arterialized blood. The second component is a second gas exchange membrane which exchanges NO for O2in the arterialized blood. The first and second components can be either structurally separate components in fluid communication or combined as one structure containing separate reaction areas within the oxygenation compartment. In either case, the second component is down-stream of the first component, as defined by the direction of blood flow in the device. Thus, NO-containing gas is administered either into the oxygenation compartment after O2has been administered into the oxygenation compartment and after CO2has been released, or NO is administered downstream of the oxygenation compartment (after blood has left the oxygenator but before it is delivered back into the patient) or both.

FIG. 2illustrates oxygenation compartment113of an ECMO device, wherein oxygenation of blood and delivery of NO both occur within gas transfer unit121. In this embodiment, blood enters oxygenation compartment113through inlet127, flows into chamber123, and exits oxygenation compartment113through outlet126. Chamber123is in contact with gas permeable membrane124of gas transfer unit121. Oxygen source125is also in fluid communication with gas transfer unit121through inlet131. As blood enters the upstream portion of chamber123, oxygen introduced into gas transfer unit121from oxygen source125diffuses through gas permeable membrane124into the blood, exchanging oxygen for CO2. The portion of gas transfer unit121downstream of inlet131is in fluid communication with NO delivery device118, through inlet132. NO delivery device118is in fluid communication with NO generator/reservoir117to deliver NO to gas transfer unit121. As the oxygenated blood in chamber123comes into contact with gas permeable membrane124downstream of inlet131, NO introduced into gas transfer unit121through inlet132diffuses through gas permeable membrane124into the oxygenated blood, exchanging NO for oxygen. After delivery of oxygen and NO to the blood, remaining oxygen and NO may be removed from gas transfer unit121to venting device122via outlet133in fluid communication with gas transfer unit121.

FIG. 3illustrates oxygenation compartment113of an ECMO device, wherein oxygenation of blood and delivery of NO occur within structurally separate components221and229of oxygenation compartment213. In this embodiment, blood enters oxygenation compartment213through inlet227, flows into chamber223, and exits oxygenation compartment213through outlet226. Chamber223is in contact with oxygen permeable membrane224of oxygen transfer unit221. Oxygen source225is also in fluid communication with oxygen transfer unit221through inlet231. As blood enters the upstream portion of chamber223, oxygen introduced into oxygen transfer unit221from oxygen source225diffuses through oxygen permeable membrane224into the blood, exchanging oxygen for CO2. Downstream of inlet231, remaining oxygen may be removed from oxygen transfer unit221to oxygen venting device222via outlet233in fluid communication with oxygen transfer unit221. The downstream portion of chamber223is in contact with NO permeable membrane230of NO transfer unit229. NO delivery device218is also influid communication with NO transfer unit229through inlet232. NO delivery device218is in fluid communication with NO generator/reservoir217to deliver NO to NO chamber229. As oxygenated blood flows to the downstream portion of chamber223, it comes into contact with NO permeable membrane230of NO transfer unit229, and NO introduced into NO transfer unit229through inlet232diffuses into the oxygenated blood, exchanging NO for oxygen. After delivery of NO to the blood, remaining NO may be removed from NO transfer unit229to NO venting device228via outlet234in fluid communication with NO transfer unit229.

FIG. 4illustrates oxygenation compartment313of an ECMO device, wherein oxygenation of blood occurs within oxygenation compartment313and delivery of NO to the blood occurs downstream of and outside oxygenation compartment313. In this embodiment, blood enters oxygenation compartment313through inlet327, flows into chamber323, and exits oxygenation compartment313through outlet326. Chamber323is in contact with oxygen permeable membrane324of oxygen transfer unit321within oxygenation compartment313. Oxygen source325is also in fluid communication with oxygen transfer unit321through inlet331. As blood enters the upstream portion of chamber323, oxygen introduced into oxygen transfer unit321from oxygen source325diffuses through oxygen permeable membrane324into the blood, exchanging oxygen for CO2. Downstream of inlet331, remaining oxygen may be removed from oxygen transfer unit321to oxygen venting device322via outlet333in fluid communication with oxygen transfer unit321. The downstream portion of chamber323is in contact with NO permeable membrane330of NO transfer unit329, which is outside oxygenation compartment313. NO delivery device318is also influid communication with NO transfer unit329through inlet332. NO delivery device318is in fluid communication with NO generator/reservoir317to deliver NO to NO chamber329. As oxygenated blood exits oxygenation compartment313and flows to the downstream portion of chamber323, it comes into contact with NO permeable membrane330of NO transfer unit329, and NO introduced into chamber329through inlet332diffuses into the oxygenated blood, exchanging NO for oxygen. After delivery of NO to the blood, remaining NO may be removed from NO transfer unit329to NO venting device328via outlet334in fluid communication with NO transfer unit329.

The NO-containing gas may be administered in the oxygenator after the blood has been partially oxygenated or fully oxygenated and may be administered separately from the addition of the oxygen. The NO-containing gas is typically administered after O2administration and CO2release.

In various embodiments, methods of the present invention include delivery of NO-containing gas directly into arterial blood by injection, catheterization, infusion, or continuous infusion into an artery, for example, a central or peripheral artery (e.g., the aorta, femoral, brachial, radial, ulnar, dorsalis pedis, etc.).