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Title:  Method for increasing plasma volume by administering a plasma expander comprising basic alpha keratose
United States Patent: 
8,021,830
Issued: 
September 20, 2011

Inventors:
 Van Dyke; Mark E. (Winston Salem, NC)
Assignee:
Wake Forest University Health Sciences (Winston-Salem, NC)
Appl. No.: 
12/209,773
Filed:
 September 12, 2008


 

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Abstract

A liquid plasma expander or resuscitation fluid composition for use in a subject in need thereof, comprising, consisting of; or consisting essentially of: (a) a keratin derivative (preferably alpha keratose, gamma keratose, or combinations thereof, and with basic alpha keratose preferred over acidic alpha keratose); and (b) an electrolyte solution, with the keratin derivative solubilized in the electrolyte solution to form a homogeneous liquid composition. Blood substitutes formed therefrom and methods of making and using the same are also described.

Description of the Invention

FIELD OF THE INVENTION

The present invention is generally related to plasma expanders and blood substitutes, and is particularly related to high viscosity plasma expanders and blood substitutes.

BACKGROUND OF THE INVENTION

Many biocompatible polymeric materials have been investigated as potential plasma expanders and/or blood substitutes. Historically, there have been two approaches: 1) the use of synthetic compounds that are biocompatible, and 2) the use of biological materials that are polymeric. In the first category, materials such as hydroxyethyl starch and perfluorocarbon liquid have been evaluated (See, e.g., S. Kasper et al., J. Clin. Anesth. 13, 486-90 (2001); T. Kaneki et al., Resuscitation 52, 101-08 (2002); R. Spence et al., Art Cells, Blood Sibst., Immobil Biotech. 22, 955-63 (1999)). In the second group is gelatin, albumin, and crosslinlked hemoglobin (I. Tigchelaar et al., Eur. J. Cardo-thor. Surg. 11, 626-32 (1997); S. Gould et al., World J. Surg. 20, 1200-7 (1996). More recently, alpha-keratose has been suggested. See A. Widra, U.S. Pat. No. 6,746,836 (Jun. 8, 2004).

Because the functional consequences of changing the flow properties of blood are not readily predictable, the development of plasma expanders and/or blood substitutes is a complicated matter. In arterial blood vessels (diameter >100 micron) blood viscosity is proportional to hematocrit (Hct) squared, and in the smaller vessels it is linearly proportional to Hct. In the systemic circulation, Hct is approximately constant down to 100 micron diameter vessels. It falls monotonically down to the capillaries where it is approximately half of the systemic value. The reverse occurs in the venous circulation, where it is higher than arterial because of fluid filtration in the microcirculation.

In acute conditions such as accompanying severe trauma, the decrease of Hct is not deemed dangerous until the transfusion trigger (blood hemoglobin content beyond which a blood transfusion is indicated) is reached. However, this exposes the vasculature to low blood viscosity when conventional plasma expanders are used to maintain blood volume. There appears to be no well-defined benefit to lowering blood viscosity, excepting when it is pathologically high, and lowering blood viscosity through hemodilution is considered to have no adverse effects. Richardson and Guyton determined that changes in blood viscosity are accompanied by compensatory changes in cardiac output, which compensate for changes in intrinsic oxygen carrying capacity of blood due to changes in Hct (T. Richardson et al., Am. J. Physiol. 197, 1167-70 (1959)). This was confirmed systemically and in the microcirculation (K. Messmer, Surg. Clins. N. Am. 55, 659-78 (1975); S. Mirhashemi et al., Am. J. Physiol 254 (Heart Circ. Physiol. 13) H411-16 (1988); A. Tsai et al., Int. J. Microcirc: Clin. Exp 10, 317-34 (1991)). Empirically, the transfusion trigger is set at 7 g Hb/dl (Hct.about.22%).

Microvascular Hcts are lower than systemic due to the presence of a plasma layer that proportionally occupies a greater portion of the vessel lumen, thus blood viscosity is also lower. The transition from macro to microcirculation in terms of vessel dimensions. Hct, and hemodynamics is gradual. Blood theological properties also change gradually and blood viscosity in the circulation depends on location. The reduction of Hct with a crystalloid or colloidal plasma expander tends to equalize the theological properties of blood and viscosity throughout the circulation.

When a plasma expander is used to remedy hemorrhage, systemic Hct decreases, significantly reducing blood viscosity in large vessels due to the squared dependence of viscosity on Hct. Viscosity of blood in small vessels is much less affected since Hct is low to begin with. Conversely, small vessel blood viscosity is greatly influenced by the viscosity of the plasma expander. If its viscosity is low, blood viscosity drops significantly in the small vessels as well as in the large vessels, although for somewhat different reasons. In conventional theory, this reduction in viscosity increases blood flow and may improve oxygen delivery.

However, the literature supports the concept that high viscosity plasma is either beneficial, or has no adverse effect in conditions of extreme hemodilution. Waschke et al. found that cerebral perfusion is not changed when blood is replaced with fluids of the same intrinsic oxygen carrying capacity over a range of viscosities varying from 1.4 cp to 7.7 cp (K. Waschke et al., J. Cereb. Blood Flow & Metab. 14, 871-976 (1994)) Krieter et al., varied the viscosity of plasma by adding dextran 500 k Daltons (Da) and found that medians in tissue pO.sub.2 in skeletal muscle where maximal at a plasma viscosity of 3 cp, while for liver the maximum occurred at 2 cp (H. Krieter et al., Acta Anaest. Scad. 39, 326-44 (1995)). In general they found that up to a 3 fold increase in blood plasma viscosity had no effect on tissue oxygenation and organ perfusion when blood was hemodiluted. de Witt et al., found elevation of plasma viscosity causes sustained NO-mediated dilatation in the hamster muscle microcirculation (C. deWitt et al., Pflugers Arch. 434, 54-61 (1997)).

Hct reductions should improve blood perfusion through the increase of blood fluidity. However at a Hct near to and beyond the transfusion trigger the heart cannot further increase flow and as viscosity falls, so does blood pressure. The fall of pressure is deleterious for tissue perfusion because it decreases functional capillary density (FCD) in the normal circulation and in hypotension following hemorrhage (L. Lindbom et al., Int. J. Microcirc: Clin. Exp 4, 121-7 (1985)). FCD is a critical microvascular parameter in survival during acute blood losses. In a hamster model subjected to 4-hr 40 mmHg hemorrhagic shock, the fall of FCD accurately predicts outcome and separates survivors from non survivors when this parameter decreases below 40% of control (H. Kerger et al., Am. J. Physiol 270 (Heart. Circ. Physiol. 39), H827-36 (1996)).

High viscosity plasma restores mean arterial pressure (MAP) in hypotension without vasoconstriction. Furthermore, the shift of pressure and pressure gradients from the systemic to the peripheral circulation increases blood flow, which in combination with increased plasma viscosity maintains shear stress in the microcirculation. This is needed for shear stress dependant NO and prostaglandin release from the endothelium and to maintain FCD (J. Frangos et al., Science 227, 1477-79 (1985)). Conversely, reduced blood viscosity decreases shear stress and the release of vasodilators, causing vasoconstriction and offsetting any benefit of reducing the theological component of vascular resistance. Since resistance depends on the 4.sup.th power of vascular radius and the 1.sup.st power of blood viscosity, the effect of reducing blood viscosity with a low viscosity plasma expander is that it reduces oxygen delivery to the tissue once blood viscosity falls below a threshold value. This threshold has been determined in our experimental model as about 2.5 cp.

Tissue perfusion with reduced blood viscosity may be deleterious at the cellular/endothelial level. There is evidence that genes are activated following changes in the mechanical environment of cells. It is also been established that the endothelium uniquely responds to changes in its mechanical and oxygen environment according to programmed genetic schemes. Among these responses is the mechanism for apoptosis (cell self destruction), which is activated through a genetically controlled suicide process that eliminates cells no longer needed or excessively damaged. In this context, hemodilution with low viscosity plasma expanders may cause cellular and tissue damage due to hypoxia and/or to the reduced vessel wall shear stress. Hypoxia/ischemia may contribute to endothelial impairment due to inflammatory reactions. Activation of endothelium, platelets and neutrophils, leading to additional damage through the liberation of cytokines, can induce endothelial apoptosis (B. Robaye et al., Am. J. Pathol. 38, 447-53 (1991)).

Studies in a hamster model show that extreme hemodilution (where Hct is 20% of control) with dextran 70 kDa, causes hypotension and a drop in FCD to near pathological values (A. Tsai et al., Proc. Natl. Acacd. Sci. USA 95, 6590-5 (1998); A. Tsai. Transfusion 41, 1290-8 (2001)). This is prevented by increasing plasma viscosity so that the diluted blood has a systemic viscosity of about 2.8 cp, which was achieved by infusing dextran 500 kDa. Thus, high viscosity plasma substitutes can be an alternative to the use of blood for maintaining MAP and an adequate level of FCD (A. Tsai et al., Biorheology 38, 229-37 (2001)). However, the known high viscosity plasma expanders such as gelatin, albumin, hydroxyethyl starch, polyvinyl-pyrrolidine, and dextran are all either non-human derived or synthetic. As such, each suffers from considerable limitations in their clinical applicability due to biocompatibility, cost, or both. What is needed is a fluid based on a substantially biocompatible material that is inexpensive, pathogen free and ambient storable. Resuscitation fluids based on keratins offer this potential.

Human hair is one of the few autologous tissues that can be obtained without additional surgery. It is also a rich source of keratins. Equally important, the biocompatibility of keratins within a species, and indeed across species is high, making allogenous and xenogenous keratins viable candidates for medical applications. The keratins found in hair, wool, and other keratinous tissues can be extracted and purified using methods known in the art, and used for formulating plasma substitutes with fluid properties that will maintain MAP and FCD. Depending on the species from whence the keratins come, the biocompatibility can also be optimized with human hair keratins being the most optimal. Keratin fluids are inexpensive to produce, can be sterilized, and are stable under ambient temperature storage.

However, the keratin-based fluid described in A. Widra would not appear to be the most optimized resuscitation medium based on the new paradigm of preserving FCD for three important reasons. First, the type of keratin used in the experiments was a highly hydrolyzed form of keratose, represented in Scheme 1 below, which is not likely to be capable of attaining the viscosic properties required by the application.

Second, hydrolyzed forms of keratose are compatible with blood in that they do not instigate appreciable levels of red blood cell aggregation, but their oncotic pressure is too low to be of benefit. Third, less hydrolyzed, high molecular weight forms of keratose tend to aggregate red blood cells, thus making the material deleterious to the restoration of FCD. Hence their remains a need for new approaches to developing keratin-based high viscosity plasma substitutes.

SUMMARY OF THE INVENTION

A first aspect of the invention is a liquid plasma expander or resuscitation fluid composition for use in a subject in need thereof, comprising, consisting of, or consisting essentially of: (a) a keratin derivative (preferably alpha keratose, gamma keratose, or combinations thereof); and (b) an electrolyte solution, with the keratin derivative solubilized in the electrolyte solution to form a homogeneous liquid composition.

A particular aspect of the foregoing is a liquid plasma expander composition in which the keratin derivative comprises alpha keratose, where the alpha keratose consists of at least 80, 90, 95 or 99 percent by weight of basic alpha keratose (or more), and where the alpha keratose consists of not more than 20, 10, 5 or 1 percent by weight of acidic alpha keratose (or less).

A particular aspect of the foregoing is a liquid plasma expander composition for use in a subject in need thereof, comprising, consisting of or consisting essentially of: (a) from 0.1 to 10 or 20 percent by weight of basic alpha keratose; (b) from 0 to 5 or 10 percent by weight of gamma keratose; and (c) from 80 or 90 to 99.9 percent by weight of an electrolyte solution. Preferably, the basic alpha keratose and the gamma keratose are solubilized in said electrolyte solution to form a homogeneous liquid composition. Preferably the homogeneous liquid composition has a pH of 7 to 8 or 9; preferably the homogeneous liquid composition has an osmolarity of 100 or 200 to 500 or 600 milliosmoles/Liter; and preferably the homogeneous liquid composition has a viscosity of 2 or 4 to 15 or 20 centipoise. Preferably the homogeneous liquid composition, when contacted to red blood cells, forms aggregates of said blood cells of less than 25 microns in diameter.

The basic alpha keratose is preferably produced by separating basic alpha keratose from a mixture of acidic and basic alpha keratose, e.g., by ion exchange chromatography, and preferably the basic alpha keratose has an average molecular weight of from 10 to 100 or 200 kilodaltons. Optionally but preferably the process further comprises the steps of re-disolving said basic alpha-keratose in a denaturing solution (such as a buffer solution), optionally in the presence of a chelating agent to complex trace metals, and the re-precipitating the basic alpha keratose from the denaturing solution. It will be appreciated that the composition preferably contains not more than 5, 2, 1, or 0.1 percent by weight of acidic alpha keratose, or less.

A second aspect of the present invention is a blood substitute composition for use in a subject in need thereof, comprising, consisting of, or consisting essentially of: a plasma expander or resuscitation fluid as described above, and red blood cells (RBCs) where the RBCs form an essentially single cell suspension of RBCs therein.

A third aspect of the present invention is a method of increasing plasma volume in a subject in need thereof, comprising administering the subject a plasma expander or resuscitation fluid composition as described above in an amount effective to increase the plasma volume of said subject.

A fourth aspect of the present invention is a method of increasing the volume of available blood substitute for treatment in a subject in need thereof, comprising the steps of: (a) obtaining a volume of donor blood and determining the Hct; (b) separating and isolating the RBCs from said donated blood; and (c) diluting said isolated RBCs to a final Hct of not less than 10% of the original Hct but not greater than 70% by adding an appropriate amount of the plasma expander composition as described above.

A further aspect of the present invention is the use of a keratin derivative as described herein for the preparation of a plasma expander or resuscitation fluid for carrying out a method as described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The disclosures of all United States patents cited herein are to be incorporated by reference herein in their entirety.

1. Keratin materials. Keratin materials are derived from any suitable source including but not limited to wool and human hair. In one embodiment keratin is derived from end-cut human hair, obtained from barbershops and salons. The material is washed in hot water and mild detergent, dried, and extracted with a nonpolar organic solvent (typically hexane or ether) to remove residual oil prior to use.

Keratose Fractions. Keratose fractions are obtained by any suitable technique. In one embodiment they are obtained using the method of Alexander and coworkers (P. Alexander et al., Biochem. J. 46, 27-32 (1950)). Basically, the hair is reacted with an aqueous solution of peracetic acid at concentrations of less than ten percent at room temperature for 24 hours. The solution is filtered and the alpha-keratose fraction precipitated by addition of mineral acid to a pH of ca. 4. The alpha-keratose is separated by filtration, washed with additional acid, followed by dehydration with alcohol, and then dried under vacuum. Increased purity can be achieved by redissolving the keratose in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris base buffer solution, re-precipitating, re-dissolving, dialyzing against deionized water, and re-precipitating at pH 4.

The gamma-keratose fraction remains in solution at pH 4 and is isolated by addition to a water-miscible organic solvent such as alcohol, followed by filtration, dehydrated with additional alcohol, and dried under vacuum. Increased purity can be achieved by redissolving the keratose in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution, reducing the pH to 4 by addition of a mineral acid, removing any solids that form, neutralizing the supernatant, re-precipitating the protein with alcohol, re-dissolving, dialyzing against deionized water, and reprecipitating by addition to alcohol. The amount of alcohol consumed in these steps can be minimized by first concentrating the keratose solution by distillation.

Kerateine Fractions. Kerateine fractions are obtained using a combination of the methods of Bradbury and Chapman (J. Bradbury et al., Aust. J. Biol. Sci. 17, 960-72 (1964)) and Goddard and Michaelis (D. Goddard et al., J. Biol. Chem. 106, 605-14 (1934)). Essentially, the cuticle of the hair fibers is removed ultrasonically in order to avoid excessive hydrolysis and allow efficient reduction of cortical disulfide bonds in a second step. The hair is placed in a solution of dichloroacetic acid and subjected to treatment with an ultrasonic probe. Further refinements of this method indicate that conditions using 80% dichloroacetic acid, solid to liquid of 1:16, and an ultrasonic power of 180 Watts are optimal (H. Ando et al., Sen'i Gakkaishi 31(3), T81-85 (1975)). Solid fragments are removed from solution by filtration, rinsed and air dried, followed by sieving to isolate the hair fibers from removed cuticle cells.

Following ultrasonic removal of the cuticle, alpha- and gamma-kerateines are obtained by reaction of the denuded fibers with mercaptoethanol. Specifically, a low hydrolysis method will be used at acidic pH (E. Thompson et al., Aust. J. Biol. Sci. 15, 757-68 (1962)). In a typical reaction, hair is extracted for 24 hours with 4M mercaptoethanol that has been adjusted to pH 5 by additional of a small amount of potassium hydroxide in deoxygenated water containing 0.02M acetate buffer and 0.001M surfactant.

The solution is filtered and the alpha-kerateine fraction precipitated by addition of mineral acid to a pH of ca. 4. The alpha-kerateine is separated by filtration, washed with additional acid, followed by dehydration with alcohol, and then dried under vacuum. Increased purity is achieved by re-dissolving the kerateine in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution, re-precipitating, re-dissolving, dialyzing against deionized water, and re-precipitating at pH 4.

The gamma-kerateine fraction remains in solution at pH 4 and is isolated by addition to a water-miscible organic solvent such as alcohol, followed by filtration, dehydrated with additional alcohol, and dried under vacuum. Increased purity is achieved by redissolving the kerateine in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution, reducing the pH to 4 by addition of a mineral acid, removing any solids that form, neutralizing the supernatant, re-precipitating the protein with alcohol, re-dissolving, dialyzing against deionized water, and reprecipitating by addition to alcohol. The amount of alcohol consumed in these steps can be minimized by first concentrating the keratose solution by distillation.

In an alternate method, the kerateine fractions are obtained by reacting the hair with an aqueous solution of sodium thioglycolate.

Meta-Keratins. Meta-keratins are synthesized from both the alpha- and gamma-fractions of kerateine using substantially the same procedures. Basically, the kerateine is dissolved in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution. Pure oxygen is bubbled through the solution to initiate oxidative coupling reactions of cysteine groups. The progress of the reaction is monitored by an increase in molecular weight as measured using SDS-PAGE. Oxygen is continually bubbled through the reaction solution until a doubling or tripling of molecular weight is achieved. The pH of the denaturing solution can be adjusted to neutrality to avoid hydrolysis of the proteins by addition of mineral acid.

Keratin Intermediate Filaments. IFs of human hair fibers are obtained using the method of Thomas and coworkers (H. Thomas et al., Int. J. Biol. Macromol. 8, 258-64 (1986)). This is essentially a chemical etching method that reacts away the keratin matrix that serves to "glue" the IFs in place, thereby leaving the IFs behind. In a typical extraction process, swelling of the cuticle and sulfitolysis of matrix proteins is achieved using 0.2M Na.sub.2SO.sub.3, 0.1M Na.sub.2O.sub.6S.sub.4 in 8M urea and 0.1M Tris-HCl buffer at pH 9. The extraction proceeds at room temperature for 24 hours. After concentrating, the dissolved matrix keratins and IFs are precipitated by addition of zinc acetate solution to a pH of ca. 6. The IFs are then separated from the matrix keratins by dialysis against 0.05M tetraborate solution. Increased purity is obtained by precipitating the dialyzed solution with zinc acetate, redissolving the IFs in sodium citrate, dialyzing against distilled water, and then freeze drying the sample.

2. Formulations. Dry powders may be formed of keratin derivatives as described above in accordance with known techniques such as freeze drying or lyophilization. In some embodiments, a liquid plasma expander composition of the invention may be produced by mixing such a dry powder composition form with an aqueous solution to produce a homogeneous liquid plasma expander composition comprising an electrolyte solution having said keratin derivative solubilized therein. The mixing step can be carried out at any suitable temperature, typically room temperature, and can be carried out by any suitable technique such as stirring, shaking, agitation, etc. The salts and other constituent ingredients of the electrolyte solution (e.g., all ingredients except the keratin derivative and the water) may be contained entirely in the dry powder, entirely within the aqueous composition, or may be distributed between the dry powder and the aqueous composition. For example, in some embodiments, at least a portion of the constituents of the electrolyte solution are contained in the dry powder.

In the composition the keratin derivatives (particularly alpha and/or gamma kerateine and alpha and/or gamma keratoses) have an average molecular weight of from about 10 to 70 or 100 kiloDaltons. Other keratin derivatives, particularly meta-keratins, may have higher average molecular weights, e.g., up to 200 or 300 kiloDaltons. In general, the keratin derivative (this term including combinations of derivatives) may be included in the composition in an amount of from about 0.1, 0.5 or 1 percent by weight up to 3, 4, 5, or 10 percent by weight. The composition when mixed preferably has a viscosity of about 1 or 1.5 to 4, 8, 10 or 20 centipoise. Viscosity at any concentration can be modulated by changing the ratio of alpha to gamma keratose. Studies have shown that viscosities as high as 7.7 have no deleterious effects (see K. Waschke et al., J. Cereb. Blood Flow & Metab. 14, 871-976 (1994) and H. Krieter et al., Acta Anaest. Scad. 39, 326-44 (1995)).

The electrolyte solution may be any suitable electrolyte solution, including but not limited to saline solution (particularly normal saline), Ringer's solution, lactated Ringer's solution, commercially available solutions such as NORMOSOL.RTM.-R isotonic fluid (available from Abbott Laboratories, Chicago, Ill. USA), and combinations thereof. Examples of suitable electrolyte compositions include but are not limited to those described in U.S. Pat. No. 6,746,836 to Widra. The complete composition when mixed preferably has an osmolarity of 200 to 400 milliosmoles/Liter and a pH of about 7 to 8.

The composition is preferably sterile and non-pryogenic. The composition may be provided preformed and aspectically packaged in a suitable container, such as a flexible polymeric bag or bottle, or may be provided as a kit of sterile dry powder in one container and sterile aqueous solution in a separate container for mixing just prior to use. When provided pre-formed and packaged in a sterile container the composition preferably has a shelf life of at least 4 or 6 months (up to 2 or 3 years or more) at room temperature, prior to substantial loss of viscosity (e.g., more than 10 or 20 percent) and/or substantial precipitation of the keratin derivative (e.g., settling detectable upon visual inspection).

3. Subjects and administration. As noted above, the present invention provides a method of increasing plasma volume in a subject (human or animal) in need thereof, or of replacing or augmenting whole blood in a subject in need thereof, comprising administering said subject a plasma expander or blood substitute, respectively, as described above in an amount effective to resuscitate said subject.

The dose or volume administered to the subject will depend upon factors such as the age and general health of the subject, the particular condition of the subject, the disorder being treated and the severity of that disorder, etc., and can be determined by skilled persons in accordance with known techniques. In some embodiments the volume administered will be between about 0.5 or 1 to 50 or 70 mL per Kg subject body weight. In some embodiments the volume administered will be from 0.1 or 0.2 Liters up to 3 or 4 Liters total per subject. For example, the resuscitation fluid can be utilized up to the transfusion trigger (Hct. of ca. 22%). This means that for an average man with a Hct of ca. 54% and a blood volume of ca. 5 L, he can be transfused with up to 3 L of plasma expander/resuscitation fluid of the invention before blood transfusion is necessary. Hct and blood volume vary by gender and age, so target volumes would vary accordingly. In another example, for neonatal shock, the composition may be administered in aliquots of between 2 to 10 mL per Kg every few minutes as necessary.

In general, subjects in need thereof include subjects in shock, typically due to acute or chronic bleeding. Particular subjects include but are not limited to subjects suffering from a laceration, incision or other injury to any portion of the body, such as an extremity, or suffering from internal injury to an organ such as the liver. The internal injury may be acute, as resulting from trauma, or chronic, such as a bleeding ulcer or diverticulitis.

Subjects that may be treated by the methods of the invention include patients undergoing a surgical procedure, where bleeding is a consequence of the surgical procedure. In cases where the surgical procedure is elective, the subject may donate whole blood before the surgery to be used in the preparation of an autologous keratin-based blood substitute.

Subjects that may be treated by the methods of the invention include burn victims, particularly severe burn victims, where blood fluid is required to carry and clear burn toxins from the body to avoid organ poisoning and organ failure.

In addition to administer to subjects, the plasma expander compositions of the present invention may be used as bath, storage or rinse compositions for organs (particularly mammalian organs of the same species as described above in connection with subjects) in connection with organ transplant procedures. Suitable organs include but are not limited to kidney, heart, lung, liver, etc.
 

Claim 1 of 14 Claims

1. A method of increasing plasma volume in a subject in need thereof, comprising administering said subject a liquid plasma expander in an amount effective to increase the plasma volume of said subject, wherein said plasma expander consists essentially of: (a) from 0.1 to 10 percent by weight of basic alpha keratose; said basic alpha keratose produced by the process of separating basic alpha keratose from a mixture of acidic and basic alpha keratose by ion exchange chromatography; and with said basic alpha keratose having an average molecular weight of from 10 to 100 kilodaltons; (b) from 0 to 5 percent by weight of gamma keratose; and (c) from 90 to 99.9 percent by weight of an electrolyte solution; with said basic alpha keratose and said gamma keratose solubilized in said electrolyte solution to form a homogeneous liquid composition having: (i) a pH of 7-8; (ii) an osmolarity of 200 to 500 milliosmoles/Liter; and (iii) a viscosity of 2 to 20 centipoise at a temperature of 37 degrees Celsius as determined with a Brookfield viscometer having a cone and plate geometry with a cone angle of 0.02 radians at a constant frequency of 30 rotations per minute.
 

 

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