Microspheres of Hydrolysed Starch with Endogenous, Charged Ligands

Abstract

The resent invention relates to biodegradable microspheres having a diameter of 1-2000 μm comprising cross-linked hydrolysed starch onto which at least one type of ligand has been coupled via a carboxylic ester bond. The ligand shall be an endogenous, charged molecule with a molecular mass of less than 1000 Da comprising at least one additional carboxylic acid function in addition to the one utilised for coupling the ligand to the micro-sphere and/or at least one amine function. On average 0.05-1.5 ligands are coupled to each glucose moiety in the hydrolysed starch.

1 .- 20 . (canceled) 
     
     
         21 . A method for carrying out hemostasis comprising the step of administering an effective amount of a biodegradable microsphere having a diameter of 10 to 2000 μm comprising cross-linked hydrolysed starch onto which at least one type of ligand, selected from the group consisting of amino acids and nitrogen containing organic acids, has been coupled via a carboxylic ester bond formed between the carboxylic acid group of the ligand and a hydroxyl group of a glucose residue in the cross-linked hydrolysed starch, wherein said ligand is an endogenous, charged molecule with a molecular mass of less than 1000 Da comprising at least one additional amine function, said ligand being positively charged or zwitter ionic, and wherein on average 0.05 to 1.5 ligands have been coupled to each glucose moiety in the hydrolysed starch, to a mammal suffering from a bleeding wound, thereby carrying out hemostasis. 
     
     
         22 . A microsphere according to  claim 21 , wherein said ligand is positively charged. 
     
     
         23 . A microsphere according to  claim 22 , wherein the ligand has a physiologically active counter ion. 
     
     
         24 . The method according to  claim 21 , wherein the microsphere has a mean diameter of 10 to 200 μm. 
     
     
         25 . The method according to  claim 24 , wherein the ligand has a physiologically active counter ion, the counter ion being ellagic acid. 
     
     
         26 . The method according to  claim 21 , wherein the ligand is an amino acid selected from the group consisting of arginine, histidine, lysine, glycine, proline, alanine, isoleucine, leucine, phenylalanine, tryptophan, tyrosine, valine, serine, aspargine, glutamine, threonine, glutamic acid and aspartic acid; or a nitrogen containing organic acid selected from the group consisting of betaine, carnitine, creatine, methylglycine, and dimethylglycine. 
     
     
         27 . The method according to  claim 26 , wherein the ligand is an amino acid selected from the group consisting of arginine, histidine, lysine, glycine, proline, alanine, isoleucine, leucine, phenylalanine, tryptophan, tyrosine, valine, serine, aspargine, glutamine, threonine; or a nitrogen containing organic acid selected from the group consisting of betaine, carnitine, creatine, methylglycine, and dimethylglycine. 
     
     
         28 . The method according to  claim 27 , wherein the ligand is a nitrogen containing organic acid selected from the group consisting of betaine, carnitine, creatine, methylglycine, and dimethylglycine. 
     
     
         29 . A method for carrying out wound healing comprising administering an effective amount of a material comprising biodegradable microspheres having a diameter of 10 to 2000 μm comprising cross-linked hydrolysed starch onto which at least one type of ligand, selected from the group consisting of amino acids and nitrogen containing organic acids, has been coupled via a carboxylic ester bond formed between the carboxylic acid group of the ligand and a hydroxyl group of a glucose residue in the cross-linked hydrolysed starch, wherein said ligand is an endogenous, charged molecule with a molecular mass of less than 1000 Da comprising at least one additional amine function, said ligand being positively charged, wherein on average 0.05 to 1.5 ligands have been coupled to each glucose moiety in the hydrolysed starch, and wherein said microspheres forms a three-dimensional structure comprising voids between the microspheres, to a mammal suffering from a wound, thereby carrying out wound healing. 
     
     
         30 . The method according to  claim 29 , wherein each microsphere is part of a homogenous size fraction with maximum variation of the mean diameter of ±15%. 
     
     
         31 . The method according to  claim 29 , wherein the microspheres have a mean diameter of from 200 μm to 2000 μm. 
     
     
         32 . The method according to  claim 29 , wherein the ligand is hydrophobic. 
     
     
         33 . The method according to  claim 32 , wherein the ligand is an amino acid selected from the group consisting of alanine, isoleucine, leucine, phenylalanine, tryptophan, tyrosine, and valine. 
     
     
         34 . The method according to  claim 29 , wherein the ligand is an amino acid selected from the group consisting of arginine, histidine, lysine, glycine, proline, alanine, isoleucine, leucine, phenylalanine, tryptophan, tyrosine, valine, serine, aspargine, glutamine, threonine, glutamic acid and aspartic acid; or a nitrogen containing organic acid selected from the group consisting of betaine, carnitine, creatine, methylglycine, and dimethylglycine. 
     
     
         35 . The method according to  claim 34 , wherein the ligand is an amino acid selected from the group consisting of arginine, histidine, lysine, glycine, proline, alanine, isoleucine, leucine, phenylalanine, tryptophan, tyrosine, valine, serine, aspargine, glutamine, threonine; or a nitrogen containing organic acid selected from the group consisting of betaine, carnitine, creatine, methylglycine, and dimethylglycine. 
     
     
         36 . The method according to  claim 35 , wherein the ligand is a nitrogen containing organic acid selected from the group consisting of betaine, carnitine, creatine, methylglycine, and dimethylglycine.