Title of Invention	HYPERBRANCHED AMYLOPECTIN FOR USE IN METHODS FOR SURGICAL OR THERAPEUTIC TREATMENT OF MAMMALS OR IN DIAGNOSTIC METHODS, ESPECIALLY FOR USE AS A PLASMA VOLUME EXPANDER
Abstract	ABSTRACT HYPERBRANCHED AMYLOPECTIN FOR USE IN METHODS FOR SURGICAL OR THERAPEUTIC TREATMENT OF MAMMALS OR IN DIAGNOSTIC METHODS, ESPECIALLY FOR USE AS A PLASMA VOLUME EXPANDER The invention relates to the use of hyperbranched amylopectin which has an average branch degree of between>10 and 25 mol % and a molecular weight (Mw) ranging from 40.000 - 800.000 Dalton and the derivatives thereof in methods for surgical or therapeutic treatment of human or animal bodies or in a diagnostic method, preferably as plasma volume expander. .Plasma volume expanders based on hydroxy-ethylated amylopectin have, as a result of hydroxy ethylation, hitherto exhibited the disadvantage of incomplete metabolism and thus temporary tissue storage which is linked to side-effects. According to the invention, novel plasma expanders based on polysaccharides which do not exhibit the same disadvantages as the former are provided. Improved, completely metabolised plasma expanders based on hyperbranched amylopectin which can be obtained therefrom so that native plant-amylopectins are altered by transglycosylation in such a way the adjustable, high degree of branching enables control of the serum-α-amylase decomposition so that no or only a very insignificant degree of hydroxy ethylation is necessary

Title of Invention

HYPERBRANCHED AMYLOPECTIN FOR USE IN METHODS FOR SURGICAL OR THERAPEUTIC TREATMENT OF MAMMALS OR IN DIAGNOSTIC METHODS, ESPECIALLY FOR USE AS A PLASMA VOLUME EXPANDER

Abstract

ABSTRACT HYPERBRANCHED AMYLOPECTIN FOR USE IN METHODS FOR SURGICAL OR THERAPEUTIC TREATMENT OF MAMMALS OR IN DIAGNOSTIC METHODS, ESPECIALLY FOR USE AS A PLASMA VOLUME EXPANDER The invention relates to the use of hyperbranched amylopectin which has an average branch degree of between>10 and 25 mol % and a molecular weight (Mw) ranging from 40.000 - 800.000 Dalton and the derivatives thereof in methods for surgical or therapeutic treatment of human or animal bodies or in a diagnostic method, preferably as plasma volume expander. .Plasma volume expanders based on hydroxy-ethylated amylopectin have, as a result of hydroxy ethylation, hitherto exhibited the disadvantage of incomplete metabolism and thus temporary tissue storage which is linked to side-effects. According to the invention, novel plasma expanders based on polysaccharides which do not exhibit the same disadvantages as the former are provided. Improved, completely metabolised plasma expanders based on hyperbranched amylopectin which can be obtained therefrom so that native plant-amylopectins are altered by transglycosylation in such a way the adjustable, high degree of branching enables control of the serum-α-amylase decomposition so that no or only a very insignificant degree of hydroxy ethylation is necessary

Full Text	In particular, the invention relates to a novel use of hyperbrancbed amylopectin which exhibits a specific degree of branching and a specific molecular weight Mw. In the course of the history of the development of plasma volume expanders, it has always been one of the aims to achieve the globular structure of the natural carrier of the colloidal-osmotic pressure in the serum, namely albumin. Glyco¬gen, which also occurs as a natural retention polysaccharide in the human organ¬ism, comes closest to this globular structure. Glycogen achieves its globular structure as a result of its very high degree of branching. From the structural point of view, glycogen is a glucose polysaccharide with or 1.4 glycosidic bonds, in linear sections, to which a-1,6 glycosidic branchpoints are fixed. Because glycogen itself is not available as a cheap raw material source, Wiedershehn suggested in 1957 to use instead less branched amylopectin as a starting mate¬rial for the production of the plasma expander hydroxyethyl starch (HES). In the meantime, hydroxyethyl starch is being used in the form of several different types on a very wide scale as plasma expander. This development has led to new types of hydroxethyl starch types (HES types) which exhibit an optimum volume effect with otherwise minimal side effects such as e.g. influencing clotting or intermediate retention in the tissue. The various types of HES present on the market differed regarding their molecu¬lar weight, average degree of substitution and substitution pattern. In spite of the substantial progress achieved by way of these developments, some disadvantages have remained even in the case of the HES types optimised in the last few years, particularly the inability of being completely metabolised. It is well known, however, that,chemically speaking, the hydroxyethyl ether group is metabolically extremely stable so that those anhydroglucoseunits of hydroxyethyl starch which carry hydroxyethyl ether groups are practically im¬possible to metabolise. Moreover, it is known that only those a-l ,4 glycosidic bonds in the hydroxyethyl starch molecule can be split by serum a-arnylase which are formed by non-substituted glucose units. For this reason, it has been found that even in the case of the optimized types of HESa minimal but yet still remarkablehistoretention can be ascertained at least over certain periods of time. As a further disadvantage, it has been found that HES does not possess the ideal globular structure of albumin and its intrinsic viscosity is therefore considerably higher than that of albumm. A relatively low viscosity is desirable in the case of a plasma expander because, following its application in the circulation, the total blood viscosity would be influenced in the sense of a reduction. The task therefore existed of developing new improved plasma expanders based on amylopectin which do not exhibit the disadvantages of a lack of complete metaboUsability of the amylopectin derivative hydroxyethyl starch. At the same time, the new plasma expander was to have a more globular structure and to be thus capable of forming relatively low viscosity solutions. It can also be considered to be one of the tasks of the invention to open up further fields of application for certain amylopectins. These tasks as well as further tasks not listed in detail which, however, can be derived freely and easily from the introductory explanations are achieved by the subject matter of claim 1. Preferred embodiments of the invention are the subject matter of the claims which refer back^o claim 1. V By using hyperbranched amylopectin with an average degree of branching, expressed in mole % of the anhydroglucoses carrying branch points/of between > 10 and 25 mole % and an average molecular weight Mw in the region of 40,000 to 800,000 Dalton and, if necessary, its derivatives in methods for the surgical or therapeutic treatment of the human or animal body (including that of mammals) or in diagnostic methods it is possible to open up, in a not directly foreseeable manner, on the one hand a number of new and interesting applications in the medical field for hyperbranched amylopectin. On the other hand, an almost ideal substitute for the starch-based HES products still commonly used in practice at present is provided specifically with respect to the 'plasma volume expansion' sector, leading to far fewer dangerous side effects. With respect to plasma volume expansion, it has in fact been found in connection with the invention as a result of extensive studies and investigations that the residual fractions of hydroxyethyl starch in the blood stream and in urine exhibit a strong increase in the degree of branching a few hours or even days after the application of a plasma expander in comparison with the originally infused hydroxyethyl starch {HES product). The degrees of branching, expressed in mole % of the anhydro glucoses carrying branch points thus increased from approx. 5 mole % to more than 7 mole % 2 hours after application and to 8 mole % 7 hours after application. ■fe«ws after application.:' At the same time, an even higher degree of branching of 9 or 10 mole % became apparent in the overall urine fraction48 or 42 hours af¬ter infusion. This phenomenon was observed irrespective of the molecular weight, the degree of substitution or the substitution pattern of the hydroxyethyl starch applied. This means that, when breaking down, these fractions increas¬ingly acquire a structure and/or branching approaching that resembling glyco¬gen, which is indicated in the literature as being branching at a level as high as approx. 10 mole % . Surprisingly enough, it has now been found that the relative stability of «-(! .6) branching in amylopectin and in derivatives thereof can be exploited to reduce the breakdown of amylopectin in comparison with the dominant a-amylase breakdown to such an extent that a polysaccharide capable of breaking down completely can be produced which, however, still exhibits the properties of an ideal plasma expander as regards the pharmacokinetics and/or the volume effect. Consequently, the invention comprises the use of hyperbranchedamylopectins and of derivatives of such hyperbranchedamylopectins in the medical sector. The term amylopectin should be understood to mean in general first of all bran¬ched starches or starch products with a-(l ,4) and cr(l ,6) bonds between the glucose molecules. These ramifications of the chain take place via the or(l>6) bonds. In the case of naturally occurring amylopectins these occur in an irregu¬lar manner approx. every 15 - 30 glucose segments. The molecular weight of naturally occurring amylopectin is very high, i.e. in the region of 107 to 2 x 108 Dalton. It is assumed that amylopectin, too, forms helices within certain limits. It is possible to define a degree of branching for amylopectins. The ratio of the number of anhydroglucose molecules carrying branch points (cr(l ,6) bonds) to the total number of anhydroclucose molecules of amylopectin is a measure of branching, this ratio being expressed in mole . Naturally occurring amylopectin has a degree of branching of approx. 4 mole %. However, it is known that, when considered in isolation, clusters and molecule sections of amylopectin ex¬hibit a slightly higher degree of branching compared with the natural average degree of branching. Hyperbranchedamylopectins according to the meaning of the invention are those amylopectins which exhibit a degree of branching which significantly exceeds the degree of branching known for amylopectin from nature. The degree of branching is, in any case, an average value (average degree of branching) since amylopectins are polydisperse substances. Such hyperbranchedamylopectins exhibit significantly higher degrees of branch¬ing, expressed in mole % of branching anhydroglucoses, in comparison with unchanged amylopectin or hydroxyethyl starch and consequently resemble gly¬cogen more closely in terms of their structure. The average degree of branching of hyperbranchedamylopectin necessary for the application according to the invention is in the region between > 10 and 25 mole %. This means that amylopectins useful according to the meaning of the invention exhibit on average an cr(l .6) bond and consequently a branch point approximately every 10 to 14 glucose units. If the degree of branching is below 10 mole %, the breakdown of branched amylopectin is insufficiently retarded (e .g. in the case of its use as a plasma expander). If the degree of branching is more than 25 mole %, the breakdown is excessively delayed such that its use as a plasma volume expander, for example,is precluded. A type of amylopectin that can preferably be used in the medical field is charac¬terised by a degree of branching of between 11 and 16 mole %. Other preferred hyperbranchedamylopectins exhibit a degree of branching in the region of between 13 and 16 mole %. In addition, the molecular weight Mw of hyperbranchedamylopectin is also im¬portant. The molecular weight Mw indicates the weight average of the molecular weight as is measurable by relevant methods providing this average value. These include aqueous GPC, HPLC, light scattering and such like. The hyperbranchedamylopectins suitable for use according to the invention gen¬erally exhibit a value for the weight average of the molecular weight of 40,000 to 800,000 Dalton. The lower limit value for the molecular weight range Mw is obtained in the case of the preferred applications essentially from the so-called 'renal threshold' which must be set at approx. 40,000 in the case of the hyper-branched compounds. If Mw is less than 40,000 Dalton, the molecules would be filtered off too rapidly via the kidneys. Above a Mw of 800,000 Dalton, no ad¬ditional usefulness worth mentioning would be achieved even though the limit viscosity no longer depends on the molecular weight in the case of a globular structure. Average values Mw of between 90,000 and 300,000 Dalton are preferred for use as plasma volume expanders, with molecular weights Mw of between 120,000 and 250,000 Dalton being particularly appropriate. A particular embodiment of the invention comprises hyperbranchedamylopectin, the average degree of branching being between 11 and 16 mole % and the mo¬lecular weight Mw being between 90,000 and 300,000 Dalton. Other appropri¬ate embodiments of the invention include a hyperbranchedamylopectin, the aver¬age degree of branching being between 13 and 16 mole % and the molecular weight Mw being between 120,000 and 250,000 Dalton. The above-mentioned parameters, namely the degree of branching and the mo¬lecular weight, allow a targeted effect being exerted and thus desired pharma¬cokinetics being set, in particular a desired cc-amylase breakdown being achieved. The degree of branching of amylopectin has a key role to play in this connection. However, the molecular weight, too, influences the kinetics con¬cerned. Moreover, it may also be possible to influence the kinetics of amy¬lopectin breakdown to take a desired direction by varying the distribution of the branch points. Of particular importance for breaking down amylopectin by cramylase and con¬sequently for the operation of the plasma volume expander, however, is the de¬gree of branching. As a result of the high degree of branching, the attack of a-amylase is greatly delayed and in areas of the molecule with a high density of the branch points altogether eliminated since no access of ?-amylase is possible there. Such compounds are nevertheless capable of breaking down by other en¬zymes down to oligosaccharides and finally glucose. If need be, hyperbranchedamylopectins to be used according to the invention can be obtained in the form of derivatives. Such derivatives comprise chemical de¬rivatives of amylopectin such as e.g. those obtainable by chemical or biotech¬nology conversions. Preferred derivatives of hyperbranchedamylopectin are hydroxyethylamy-lopectin, hydroxypropyl amylopectin and acetyl amylopectin. Of these, hy-droxyethyiamylopectin in rum is particularly advantageous to use. The kinetics of amylopectin breakdowncan consequently also be influenced byderivatisation. However, it is advantageous for the degree of derivatisation, e ,g. the degree of hydroxyethylation to be considerably lower in these cases in order to achieve a comparable volume effect or similar pharmacokinetics in comparison with hy-droxyethyl starch (HES) produced from normally branched amylopectin. The production of hyperbranchedamylopectinwhich is suitable according to the meaning of the invention - among other things and preferably - for use as a plasma volume expander takes place in a manner known as such by enzymatic conversion by so-called branching enzymes which catalyse the hydrolysis of cr 1,4 glycosidic bonds and their conversion to a-1,6 glycosidic compounds. Such so-called transfer enzymes can be extracted in the known way e.g. from algae according to PCT WO 0018893. However, from US patent 4454 161 and EP 0418945, other glycogen branching enzymes are known which can also be used correspondingly. The execution of enzymatic transglycosilation takes place in a manner known as such e.g. by the incubation of waxy maize starch with the corresponding enzymes under mild conditions at a pH around approx. 7,5 and temperatures of approx. 30 °C in aqueous solution. Working up of the reaction preparation takes place subsequently again in the known way, the enzymes hav¬ing been first deactivated or removed by changing the pH or by filtration steps. In a subsequent hydrolysis step which preferably takes place by means of hydro¬chloric acid, the desired molecular weight of the product is adjusted. By diafil-tration with membranes with a cut off of approx. 3,000 Dalton, the product is subsequently freed from low molecular compounds and common salt formed during the neutralization of the acidic hydrolysis preparation. The product is isolated e.g. by spray drying. Apart from being used as plasma volume expander, hyperbranchedamylopectins can also be usefully employed in other areas of medicine. Hyperbranchedamy- lopectin can thus be used for all those applications in the field of therapy and surgery in which standard HES products based on normally branched types of starch can be used. Apart from the use as plasma volume expander, this involves preferably the use for the improvement of microcirculation, the use as sedimentation aid in cell separation in connection with leucapheresis or the use for cryo-conservation of blood components such as erythrocytes or granulocytes. Model example 1 Comparative breakdown tests with differently branched ct-1-4/ a-1-6 gluco- saccharides Glycogen from oysters from SIGMA was broken down by thermoresistant a-amylse BAN 480 L from NOVOZYMES in a mixture of DMSO and water with a 30 % content of DMSO at 70 CC and a pH of 6.0. The course of the reaction was monitored by measuring the changes in the molecular weight by gas chro¬matography and the reaction was stopped after approx. 2 hours by the addition of caustic soda solution for enzyme activation. After neutralization, the product was fractionated by ultrafiltration by means of a cellulose acetate ultrafilter with a nominal cut-off of 1,000 D and 25,000 D for the removal of low molecular fractions and remaining high molecular fractions. The product was subsequently treated with the ion exchanger Amberlite IR 200 C and activated carbon, pre¬cipitated with ethanol and dried at 80 °C. The degree of branching determined by 'H NMR spectroscopy (integration of the signals of anomeric protons) gave a degree of branching of 15 mole%. The average molecular weight Mw was 7,000 Dalton. Thin boiling waxy maize starch (> 95 % amylopectin) (Cerestar) was treated in the same way as described above. The isolated, highly branched fraction of the branching cluster exhibited a degree of branching of 11 mole %, the average molecular weight Mw was 8,000 Dalton. The highly branched cluster fractions of amylopectin and glycogen were subse¬quently subjected to a breakdown test by means of porcine pancreas a-amylase (Roche) in phosphate buffer at pH 7.2 in a 1 % solution at 37 °C and with 0,5 IU/ml enzyme and the breakdown kinetics were monitored by measuring the changes in molecular weight by gel chromatography. A comparative test of the breakdown by means of commercial hydroxyethyl starch plasma volume ex¬pander was also carried out (Voluven, Fresenius Kabi). Clear differences in the breakdown kinetics were obtained. The half-life of the molecular weight (reduc¬tion of the average molecular weight Mw of the starting substance to half the initial value) was 60 minutes in the case of the fraction with a degree of branch¬ing of 15 % and consequently reached the half-life determined under the same test conditions as that of the Voluven plasma expander. The half-life for the fraction with an average degree of branching of 11 mole %, on the other hand, was only 25 minutes and it was thus considerably shorter. Model example 2 Thin boiling waxy maize starch from Cerestar with an average degree of branch¬ing determined by NMR of 4 mole % was subjected to a breakdown test by por¬cine pancreas a-arnylase according to the data given in example 1. For this pur¬pose, a I % solution was gelatinised in phosphate buffer at pH 7.2 by brief heat¬ing to approx. 90 °C and, after cooling, the enzyme was added to the prepara¬tion in a quantity resulting in 0,5 IU per ml. The test temperature was 37 °C. The breakdown kinetics were monitored by determining the changes in the mo¬lecular weight by gel chromatography. The molecular weight of the starting sub¬stance was reduced to half the value within 10 minutes under the same condi¬tions as in example 1. In comparison with the hyperbranched a-1-4/ a-1-6 glucosaccharides from ex¬ample 1, the on average relative low-branched, thin boiling waxy maize starch is thus broken down by a-amytase so rapidly that it would not be usable as plasma expander. In this way, the two model examples 1 and 2 demonstrate that even if the mo¬lecular weights are low, higher levels of branching lead to a delay in the break¬down of ^-amylase and that this effect can be used for the manufacture of a plasma expander. We claim, 1. Hyperbranched amylopectin which exhibits an average degree of branching, expressed in mole % of the anhydrogucoses carrying branch points, of between > 10 and 25 mole % and an average weight average of the molecular weight Mw in the region of 40,000 to 800,000 Dalton and derivatives thereof. 2. Hyperbranched amylopectin as claimed in claim 1 for application in methods for the surgical or therapeutic treatment of the human or animal body or in diagnostic methods. 3. Hyperbranched amylopectin as claimed in claim 1 as a plasma volume expander, 4. Hyperbranched amylopectin as claimed in claim 1 for the improvement of microcirculation. 5. Hyperbranched amylopectin as claimed in claim 1 as sedimentation aid in cell separation in connection with leucapheresis. 6. Hyperbranched amylopectin as claimed in claim 1 for the cryo-conservation of blood components such as erythrocytes of granulocytes. 7. Hyperbranched amylopectin as claimed in one of the preceding claims, the average degree of branching being between 11 and 16 mole % and the molecular weight Mw between 90,000 and 300,000 Dalton. 8. Hyperbranched amylopectin as claimed in one of the preceding claims 1 to 5, the average degree of branching being between 13 and 16 mole % and the molecular weight Mw between 120,000 and 250,000 Dalton.

Full Text

In particular, the invention relates to a novel use of hyperbrancbed amylopectin which exhibits a specific degree of branching and a specific molecular weight
Mw.
In the course of the history of the development of plasma volume expanders, it has always been one of the aims to achieve the globular structure of the natural carrier of the colloidal-osmotic pressure in the serum, namely albumin. Glyco¬gen, which also occurs as a natural retention polysaccharide in the human organ¬ism, comes closest to this globular structure. Glycogen achieves its globular structure as a result of its very high degree of branching. From the structural point of view, glycogen is a glucose polysaccharide with or 1.4 glycosidic bonds, in linear sections, to which a-1,6 glycosidic branchpoints are fixed. Because glycogen itself is not available as a cheap raw material source, Wiedershehn suggested in 1957 to use instead less branched amylopectin as a starting mate¬rial for the production of the plasma expander hydroxyethyl starch (HES). In the meantime, hydroxyethyl starch is being used in the form of several different types on a very wide scale as plasma expander. This development has led to new types of hydroxethyl starch types (HES types) which exhibit an optimum volume effect with otherwise minimal side effects such as e.g. influencing clotting or intermediate retention in the tissue.
The various types of HES present on the market differed regarding their molecu¬lar weight, average degree of substitution and substitution pattern.

In spite of the substantial progress achieved by way of these developments, some disadvantages have remained even in the case of the HES types optimised in the last few years, particularly the inability of being completely metabolised.
It is well known, however, that,chemically speaking, the hydroxyethyl ether group is metabolically extremely stable so that those anhydroglucoseunits of hydroxyethyl starch which carry hydroxyethyl ether groups are practically im¬possible to metabolise. Moreover, it is known that only those a-l ,4 glycosidic bonds in the hydroxyethyl starch molecule can be split by serum a-arnylase which are formed by non-substituted glucose units. For this reason, it has been found that even in the case of the optimized types of HESa minimal but yet still remarkablehistoretention can be ascertained at least over certain periods of time.
As a further disadvantage, it has been found that HES does not possess the ideal globular structure of albumin and its intrinsic viscosity is therefore considerably higher than that of albumm. A relatively low viscosity is desirable in the case of a plasma expander because, following its application in the circulation, the total blood viscosity would be influenced in the sense of a reduction.
The task therefore existed of developing new improved plasma expanders based on amylopectin which do not exhibit the disadvantages of a lack of complete metaboUsability of the amylopectin derivative hydroxyethyl starch. At the same time, the new plasma expander was to have a more globular structure and to be thus capable of forming relatively low viscosity solutions.

It can also be considered to be one of the tasks of the invention to open up further fields of application for certain amylopectins.
These tasks as well as further tasks not listed in detail which, however, can be derived freely and easily from the introductory explanations are achieved by the subject matter of claim 1. Preferred embodiments of the invention are the subject matter of the claims which
refer back^o claim 1.
V
By using hyperbranched amylopectin with an average degree of branching, expressed in mole % of the anhydroglucoses carrying branch points/of between > 10 and 25 mole % and an average molecular weight Mw in the region of 40,000 to 800,000 Dalton and, if necessary, its derivatives in methods for the surgical or therapeutic treatment of the human or animal body (including that of mammals) or in diagnostic methods it is possible to open up, in a not directly foreseeable manner, on the one hand a number of new and interesting applications in the medical field for hyperbranched amylopectin. On the other hand, an almost ideal substitute for the starch-based HES products still commonly used in practice at present is provided specifically with respect to the 'plasma volume expansion' sector, leading to far fewer dangerous side effects.
With respect to plasma volume expansion, it has in fact been found in connection with the invention as a result of extensive studies and investigations that the residual fractions of hydroxyethyl starch in the blood stream and in urine exhibit a strong increase in the degree of branching a few hours or even days after the application of a plasma expander in comparison with the originally infused hydroxyethyl starch {HES product). The degrees of branching, expressed in mole % of the anhydro glucoses carrying branch points thus increased from approx. 5 mole % to more than 7 mole % 2 hours after application and to 8 mole % 7 hours after application.

■fe«ws after application.:' At the same time, an even higher degree of branching of 9 or 10 mole % became apparent in the overall urine fraction48 or 42 hours af¬ter infusion. This phenomenon was observed irrespective of the molecular weight, the degree of substitution or the substitution pattern of the hydroxyethyl starch applied. This means that, when breaking down, these fractions increas¬ingly acquire a structure and/or branching approaching that resembling glyco¬gen, which is indicated in the literature as being branching at a level as high as approx. 10 mole % .
Surprisingly enough, it has now been found that the relative stability of «-(! .6) branching in amylopectin and in derivatives thereof can be exploited to reduce the breakdown of amylopectin in comparison with the dominant a-amylase breakdown to such an extent that a polysaccharide capable of breaking down

completely can be produced which, however, still exhibits the properties of an ideal plasma expander as regards the pharmacokinetics and/or the volume effect.
Consequently, the invention comprises the use of hyperbranchedamylopectins and of derivatives of such hyperbranchedamylopectins in the medical sector.
The term amylopectin should be understood to mean in general first of all bran¬ched starches or starch products with a-(l ,4) and cr(l ,6) bonds between the glucose molecules. These ramifications of the chain take place via the or(l>6) bonds. In the case of naturally occurring amylopectins these occur in an irregu¬lar manner approx. every 15 - 30 glucose segments. The molecular weight of naturally occurring amylopectin is very high, i.e. in the region of 107 to 2 x 108 Dalton. It is assumed that amylopectin, too, forms helices within certain limits.
It is possible to define a degree of branching for amylopectins. The ratio of the number of anhydroglucose molecules carrying branch points (cr(l ,6) bonds) to the total number of anhydroclucose molecules of amylopectin is a measure of branching, this ratio being expressed in mole . Naturally occurring amylopectin has a degree of branching of approx. 4 mole %. However, it is known that, when considered in isolation, clusters and molecule sections of amylopectin ex¬hibit a slightly higher degree of branching compared with the natural average degree of branching.
Hyperbranchedamylopectins according to the meaning of the invention are those amylopectins which exhibit a degree of branching which significantly exceeds the degree of branching known for amylopectin from nature. The degree of branching is, in any case, an average value (average degree of branching) since amylopectins are polydisperse substances.
Such hyperbranchedamylopectins exhibit significantly higher degrees of branch¬ing, expressed in mole % of branching anhydroglucoses, in comparison with unchanged amylopectin or hydroxyethyl starch and consequently resemble gly¬cogen more closely in terms of their structure.

The average degree of branching of hyperbranchedamylopectin necessary for the application according to the invention is in the region between > 10 and 25 mole %. This means that amylopectins useful according to the meaning of the invention exhibit on average an cr(l .6) bond and consequently a branch point approximately every 10 to 14 glucose units. If the degree of branching is below 10 mole %, the breakdown of branched amylopectin is insufficiently retarded (e .g. in the case of its use as a plasma expander). If the degree of branching is more than 25 mole %, the breakdown is excessively delayed such that its use as a plasma volume expander, for example,is precluded.
A type of amylopectin that can preferably be used in the medical field is charac¬terised by a degree of branching of between 11 and 16 mole %.
Other preferred hyperbranchedamylopectins exhibit a degree of branching in the region of between 13 and 16 mole %.
In addition, the molecular weight Mw of hyperbranchedamylopectin is also im¬portant. The molecular weight Mw indicates the weight average of the molecular weight as is measurable by relevant methods providing this average value. These include aqueous GPC, HPLC, light scattering and such like.
The hyperbranchedamylopectins suitable for use according to the invention gen¬erally exhibit a value for the weight average of the molecular weight of 40,000 to 800,000 Dalton. The lower limit value for the molecular weight range Mw is obtained in the case of the preferred applications essentially from the so-called 'renal threshold' which must be set at approx. 40,000 in the case of the hyper-branched compounds. If Mw is less than 40,000 Dalton, the molecules would be filtered off too rapidly via the kidneys. Above a Mw of 800,000 Dalton, no ad¬ditional usefulness worth mentioning would be achieved even though the limit viscosity no longer depends on the molecular weight in the case of a globular structure.

Average values Mw of between 90,000 and 300,000 Dalton are preferred for use as plasma volume expanders, with molecular weights Mw of between 120,000 and 250,000 Dalton being particularly appropriate.
A particular embodiment of the invention comprises hyperbranchedamylopectin, the average degree of branching being between 11 and 16 mole % and the mo¬lecular weight Mw being between 90,000 and 300,000 Dalton. Other appropri¬ate embodiments of the invention include a hyperbranchedamylopectin, the aver¬age degree of branching being between 13 and 16 mole % and the molecular weight Mw being between 120,000 and 250,000 Dalton.
The above-mentioned parameters, namely the degree of branching and the mo¬lecular weight, allow a targeted effect being exerted and thus desired pharma¬cokinetics being set, in particular a desired cc-amylase breakdown being achieved. The degree of branching of amylopectin has a key role to play in this connection. However, the molecular weight, too, influences the kinetics con¬cerned. Moreover, it may also be possible to influence the kinetics of amy¬lopectin breakdown to take a desired direction by varying the distribution of the branch points.
Of particular importance for breaking down amylopectin by cramylase and con¬sequently for the operation of the plasma volume expander, however, is the de¬gree of branching. As a result of the high degree of branching, the attack of a-amylase is greatly delayed and in areas of the molecule with a high density of the branch points altogether eliminated since no access of ?-amylase is possible there. Such compounds are nevertheless capable of breaking down by other en¬zymes down to oligosaccharides and finally glucose.
If need be, hyperbranchedamylopectins to be used according to the invention can be obtained in the form of derivatives. Such derivatives comprise chemical de¬rivatives of amylopectin such as e.g. those obtainable by chemical or biotech¬nology conversions.

Preferred derivatives of hyperbranchedamylopectin are hydroxyethylamy-lopectin, hydroxypropyl amylopectin and acetyl amylopectin. Of these, hy-droxyethyiamylopectin in rum is particularly advantageous to use. The kinetics of amylopectin breakdowncan consequently also be influenced byderivatisation. However, it is advantageous for the degree of derivatisation, e ,g. the degree of hydroxyethylation to be considerably lower in these cases in order to achieve a comparable volume effect or similar pharmacokinetics in comparison with hy-droxyethyl starch (HES) produced from normally branched amylopectin.
The production of hyperbranchedamylopectinwhich is suitable according to the meaning of the invention - among other things and preferably - for use as a plasma volume expander takes place in a manner known as such by enzymatic conversion by so-called branching enzymes which catalyse the hydrolysis of cr 1,4 glycosidic bonds and their conversion to a-1,6 glycosidic compounds. Such so-called transfer enzymes can be extracted in the known way e.g. from algae according to PCT WO 0018893. However, from US patent 4454 161 and EP 0418945, other glycogen branching enzymes are known which can also be used correspondingly. The execution of enzymatic transglycosilation takes place in a manner known as such e.g. by the incubation of waxy maize starch with the corresponding enzymes under mild conditions at a pH around approx. 7,5 and temperatures of approx. 30 °C in aqueous solution. Working up of the reaction preparation takes place subsequently again in the known way, the enzymes hav¬ing been first deactivated or removed by changing the pH or by filtration steps.
In a subsequent hydrolysis step which preferably takes place by means of hydro¬chloric acid, the desired molecular weight of the product is adjusted. By diafil-tration with membranes with a cut off of approx. 3,000 Dalton, the product is subsequently freed from low molecular compounds and common salt formed during the neutralization of the acidic hydrolysis preparation. The product is isolated e.g. by spray drying.
Apart from being used as plasma volume expander, hyperbranchedamylopectins can also be usefully employed in other areas of medicine. Hyperbranchedamy-

lopectin can thus be used for all those applications in the field of therapy and surgery in which standard HES products based on normally branched types of starch can be used.
Apart from the use as plasma volume expander, this involves preferably the use for the improvement of microcirculation, the use as sedimentation aid in cell separation in connection with leucapheresis or the use for cryo-conservation of
blood components such as erythrocytes or granulocytes.
Model example 1
Comparative breakdown tests with differently branched ct-1-4/ a-1-6 gluco-
saccharides
Glycogen from oysters from SIGMA was broken down by thermoresistant a-amylse BAN 480 L from NOVOZYMES in a mixture of DMSO and water with a 30 % content of DMSO at 70 CC and a pH of 6.0. The course of the reaction was monitored by measuring the changes in the molecular weight by gas chro¬matography and the reaction was stopped after approx. 2 hours by the addition of caustic soda solution for enzyme activation. After neutralization, the product was fractionated by ultrafiltration by means of a cellulose acetate ultrafilter with a nominal cut-off of 1,000 D and 25,000 D for the removal of low molecular fractions and remaining high molecular fractions. The product was subsequently treated with the ion exchanger Amberlite IR 200 C and activated carbon, pre¬cipitated with ethanol and dried at 80 °C.
The degree of branching determined by 'H NMR spectroscopy (integration of the signals of anomeric protons) gave a degree of branching of 15 mole%. The average molecular weight Mw was 7,000 Dalton.
Thin boiling waxy maize starch (> 95 % amylopectin) (Cerestar) was treated in the same way as described above. The isolated, highly branched fraction of the branching cluster exhibited a degree of branching of 11 mole %, the average molecular weight Mw was 8,000 Dalton.

The highly branched cluster fractions of amylopectin and glycogen were subse¬quently subjected to a breakdown test by means of porcine pancreas a-amylase (Roche) in phosphate buffer at pH 7.2 in a 1 % solution at 37 °C and with 0,5 IU/ml enzyme and the breakdown kinetics were monitored by measuring the changes in molecular weight by gel chromatography. A comparative test of the breakdown by means of commercial hydroxyethyl starch plasma volume ex¬pander was also carried out (Voluven, Fresenius Kabi). Clear differences in the breakdown kinetics were obtained. The half-life of the molecular weight (reduc¬tion of the average molecular weight Mw of the starting substance to half the initial value) was 60 minutes in the case of the fraction with a degree of branch¬ing of 15 % and consequently reached the half-life determined under the same test conditions as that of the Voluven plasma expander.
The half-life for the fraction with an average degree of branching of 11 mole %, on the other hand, was only 25 minutes and it was thus considerably shorter.
Model example 2
Thin boiling waxy maize starch from Cerestar with an average degree of branch¬ing determined by NMR of 4 mole % was subjected to a breakdown test by por¬cine pancreas a-arnylase according to the data given in example 1. For this pur¬pose, a I % solution was gelatinised in phosphate buffer at pH 7.2 by brief heat¬ing to approx. 90 °C and, after cooling, the enzyme was added to the prepara¬tion in a quantity resulting in 0,5 IU per ml.
The test temperature was 37 °C.
The breakdown kinetics were monitored by determining the changes in the mo¬lecular weight by gel chromatography. The molecular weight of the starting sub¬stance was reduced to half the value within 10 minutes under the same condi¬tions as in example 1.

In comparison with the hyperbranched a-1-4/ a-1-6 glucosaccharides from ex¬ample 1, the on average relative low-branched, thin boiling waxy maize starch is thus broken down by a-amytase so rapidly that it would not be usable as plasma expander.
In this way, the two model examples 1 and 2 demonstrate that even if the mo¬lecular weights are low, higher levels of branching lead to a delay in the break¬down of ^-amylase and that this effect can be used for the manufacture of a plasma expander.

We claim,
1. Hyperbranched amylopectin which exhibits an average degree of branching,
expressed in mole % of the anhydrogucoses carrying branch points, of
between > 10 and 25 mole % and an average weight average of the
molecular weight Mw in the region of 40,000 to 800,000 Dalton and
derivatives thereof.
2. Hyperbranched amylopectin as claimed in claim 1 for application in methods
for the surgical or therapeutic treatment of the human or animal body or in
diagnostic methods.
3. Hyperbranched amylopectin as claimed in claim 1 as a plasma volume
expander,
4. Hyperbranched amylopectin as claimed in claim 1 for the improvement of
microcirculation.
5. Hyperbranched amylopectin as claimed in claim 1 as sedimentation aid in cell
separation in connection with leucapheresis.
6. Hyperbranched amylopectin as claimed in claim 1 for the cryo-conservation of
blood components such as erythrocytes of granulocytes.
7. Hyperbranched amylopectin as claimed in one of the preceding claims, the
average degree of branching being between 11 and 16 mole % and the
molecular weight Mw between 90,000 and 300,000 Dalton.
8. Hyperbranched amylopectin as claimed in one of the preceding claims 1 to 5,
the average degree of branching being between 13 and 16 mole % and the
molecular weight Mw between 120,000 and 250,000 Dalton.

Documents:

351-chenp-2004 abstract.pdf

351-chenp-2004 claims duplicate.pdf

351-chenp-2004 claims.pdf

351-chenp-2004 correspondence others.pdf

351-chenp-2004 correspondence po.pdf

351-chenp-2004 description (complete) duplicate.pdf

351-chenp-2004 description (complete).pdf

351-chenp-2004 form-1.pdf

351-chenp-2004 form-18.pdf

351-chenp-2004 form-26.pdf

351-chenp-2004 form-3.pdf

351-chenp-2004 form-5.pdf

351-chenp-2004 pct.pdf

351-chenp-2004 petition.pdf

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Patent Number

227043

Indian Patent Application Number

351/CHENP/2004

PG Journal Number

07/2009

Publication Date

13-Feb-2009

Grant Date

31-Dec-2008

Date of Filing

19-Feb-2004

Name of Patentee

SUPRAMOL PARENTERAL COLLOIDS GmbH

Applicant Address

INDUSTRIESTRASSE 1-3, 61191 ROSBACH-RODHEIM,

Inventors:

#	Inventor's Name	Inventor's Address
1	SOMMERMEYER, KLAUS	IN DER LAUBACH 26, 61191 ROSBACH V.D.H.,

PCT International Classification Number

CO8B35/00

PCT International Application Number

PCT/EP02/08757

PCT International Filing date

2002-08-06

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	101 41 099.9	2001-08-22	Germany