Blood plasma substitute

The major use of vinylpyrrohdinone is as a monomer in manufacture of poly(vinylpyrrohdinone) (PVP) homopolymer and in various copolymers, where it frequendy imparts hydrophilic properties. When PVP was first produced, its principal use was as a blood plasma substitute and extender, a use no longer sanctioned. These polymers are used in pharmaceutical and cosmetic appHcations, soft contact lenses, and viscosity index improvers. The monomer serves as a component in radiation-cured polymer compositions, serving as a reactive diluent that reduces viscosity and increases cross-linking rates (see... 

First developed in Germany by I. G. Farben (W. Reppe) during the 1930s, PVP was subsequentiy widely used in Germany as a blood-plasma substitute and extender during World War II (69). In the United States, it has been manufactured since 1956 by ISP, and more recentiy by BASF. 

Poly(vinyl pyrrolidone) (PVP) was introduced by the Germans in World War II as a blood plasma substitute.A water-soluble polymer, its main value is due to its ability to form loose addition compounds with many substances. 

A number of other polysaccharides, such as glycogen, dextran, chitin, etc., possess interesting structures for chemical modification [103,104]. Dextran has been used as a blood plasma substitute. Although it can be converted to films and fibers, chitin s relatively small resource restricts its commercialization. 

In addition to murein, bacterial polysaccharides include dextrans—glucose polymers that are mostly al 6-linked and al 3-branched. In water, dextrans form viscous slimes or gels that are used for chromatographic separation of macromolecules after chemical treatment (see p.78). Dextrans are also used as components of blood plasma substitutes (plasma expanders) and foodstuffs. 

On the positive side, dextran itself has been refined and employed as a therapeutic agent in restoring blood volume for mass casualties. Natural dextrans have very high molecular weight (on the order of 10 -10 Da) and are found to be unsuitable as a blood-plasma substitute. Lower molecular weight (about 10 Da) dextran is suitable and often referred to as clinical dextran. 

Many pioneer structural investigations were carried out in other groups of polysaccharides, notably on inulin, on the xylan from esparto, on the mannan from yeast and on a series of bacterial polysaccharides amongst the latter were included somatic and lipoid-bound polysaccharides from M. tuberculosis. Noteworthy also was the work on the dextran produced by strains of Leuconostoc, which is showing grqat promise as a blood plasma substitute. 

PVPO is highly polar and water-soluble plastic. It finds applications in adhesives and as a water thickener. Water solutions can be used as blood plasma substitute or artificial blood. 

For use as a blood-plasma substitute, the dextran should have a molecular weight in the range of 50,000 to 100,000. This criterion has occasioned a concerted effort to produce dextrans in the correct range. Partial, acid hydrolysis of native dextran followed by fractionation with various solvents, or enzymic production of dextran of low molecular weight are methods which have been used. In addition, ultrasonics has been suggested as a means of depolymerizating native dextran to the correct size for clinical use. Introduction of alternative acceptors into the reaction mixture for enzymic synthesis has also been employed for this purpose it is described in an earlier Section of this Chapter. 

Soluble polyvinylpyrrolidone was first used during World War II as a blood-plasma substitute. Although it has excellent properties for this purpose, it has no longer been used for a number of decades. The organism does not metabolize the polymer, with the result that after parenteral administration, small quantities of high-molecular components may remain within the body. This problem does not exist with oral administration. 

Use Blood plasma substitute or expander, confections, lacquers, oil-well drilling muds, filtration gel, food additive. 

Dextran is a polyglucose biopolymer characterized by preponderance of a-1,6 linkage, and generally produced by enzymes from certain strains of Leuconostoc or Streptococcus. While formerly its principal utility was as a blood plasma substitute, dextran is also used in various fields such as pharmaceutical, photographic,... 

Poly(vinyl pyrrolidone) is a water-soluble polymer. Its main value is due to its ability to form loose addition compounds with many substances. It is thus used in cosmetics. The polymer has found several applications in textile treatment because of its affinity for dyestuffs. In an emergency it is used as a blood plasma substitute. Also, about 7% polymer added to whole blood allows it to be frozen, stored at liquid nitrogen temperatures for years, and thawed out without destroying blood cells. 

Numerous other polysaccharides are known, such as gum arabic and other gums and mucilages, chondroitin sulfate (found in cartilage), the blood anticoagulant heparin (found in the liver and heart), and the dextrans (used as blood plasma substitutes). 

A similar concept has been used to develop a biodegradable, water-soluble blood plasma substitute. Fauvarque and Malinge prepared a polymer where poly-(ethylene oxide) chains are hnked by cleavable pyrophosphate units. They first quantitatively phosphorylated poly(ethylene oxide) 4,000 and then condensated this prepolymer by building the pyrophosphate links. 

The only other polymer that has been included in some studies was polyvinylpyrrolidone), PVP, used as a blood plasma substitute. It is also adsorbed on the silica surface but is generally a less effective antagonist for silica, possibly because it is less strongly adsorbed. 

Acetic anhydride is an important industrial reagent. Over one-half its annual production of approximafely 750,000 fons is used for the manufacture of cellulose acetate. Cellulose acetate is a wddely used textile fiber and is the chief component of cigarette filters. Acetic anhydride is the acetylation reagent used for the production of aspirin (acetylsalicylic acid). Succinic anhydride finds use in the succinylation of gelatin used as a blood plasma substitute, as a food preservative in chicken against Salmonella, and as a dog food preservative. 

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