Temperature controlled and pH dependent self gelling biopolymeric aqueous solution

• US 20100028434A1
• Filed: 10/09/2009
• Published: 02/04/2010
• Est. Priority Date: 11/15/1999
• Status: Active Grant

• Current Assignee: Smith & Nephew Orthopaedics Ag (Smith & Nephew PLC)
• Original Assignee: Bio Syntech Canada Inc. (Biosyntech, Inc.)
• Inventors: Wang, Dong, Selmani, Amine, Chenite, Abdellatif, Chaput, Cyril
• Granted Patent: US 8,920,842 B2
• Time in Patent Office: Days
• US Class Current: 424/485
• CPC Class Codes: A61K 47/36 Polysaccharides; Derivatives thereof, e.g. gums, starch, alginate, dextrin, hyaluronic acid, chitosan, inulin, agar or pectin
• CPC Class Codes: A61K 47/42 Proteins; Polypeptides; Degradation products thereof; Derivatives thereof, e.g. albumin, gelatin or zein oligopeptides having up to five amino acids A61K47/183; polyamino acids A61K47/34
• CPC Class Codes: A61L 27/20 Polysaccharides
• CPC Class Codes: A61L 27/22 Polypeptides or derivatives thereof , e.g. degradation products
• CPC Class Codes: A61L 27/26 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 27/52 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: C08L 5/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof

Abstract

The present invention relates a biopolymeric liquid aqueous composition for producing self-gelling systems and gels, which comprises: an acidic water-based medium, 0.1 to 10% by weight of a pH-gelling acid-soluble biopolymer; and 0.1 to 10% by weight of a water-soluble molecule having a basic character and a pKa between 6.0 and 8.4, or a water-soluble residue or sequence of the molecule having a basic character and a pKa between 6.0 and 8.4. The liquid composition has a final pH ranging from 5.8 and 7.4, and forms a stable solid and homogeneous gel within a temperature range from 10 to 70° C. The present invention also relates to a method for preparing the composition and uses thereof.

Claims

1. A polymeric liquid aqueous composition for producing self-gelling systems and gels, which comprises:

a) an acidic water-based medium; and

b) 0.1 to 10% by weight of a pH-gelling acid-soluble polymer, with the proviso that said polymer is free of chitosan and chitosan derivatives; and

c) 0.1 to 10% by weight of a water-soluble molecule having a basic character and a pKa between 6.0 and 8.4;

wherein said liquid composition has a final pH ranging from 5.8 and 7.4, and forms a stable solid and homogeneous gel when heated within a temperature range from 10 to 70°

C.

2. A composition according to claim 1, wherein said composition is prepared from organic and/or inorganic acid.

3. A composition according to claim 2, wherein the organic and/or inorganic acid is selected from the group consisting of hydrochloric acid, citric acid, ascorbic acid, lactic acid, lactobionic acid, acetic acid, salicylic acid, formic acid, glutamic acid, phosphoric acid, orthophosphoric acid, and glycerophosphoric acid, or a mixture thereof.

4. A composition according to claim 1, wherein said polymer comprises a pH-gelling acid-soluble polysaccharide, polypeptidic or poly(amino acids), or synthetic polymer.

5. A composition according to claim 1, wherein said molecule is an organic salt selected from the group consisting of mono-phosphate salt, mono-sulfonate salt, mono-sulfate salt and mono-carboxylate salt.

6. A composition according to claim 1, wherein said molecule is a salt of polyol selected from the group consisting of mono-phosphate dibasic salt, mono-sulfonate salt, mono-sulfate salt and mono-carboxylate salt of polyol, said polyol being selected from the group consisting of glycerol, histidinol, acetol, diethylstil-bestrol, indole-glycerol, sorbitol, ribitol, xylitol, arabinitol, erythritol, inositol, mannitol, glucitol, palmitoyl-glycerol, linoleoyl-glycerol, oleoyl-glycerol, and arachidonoyl-glycerol, or a mixture thereof.

7. A composition according to claim 6, wherein the salt of glycerol is selected from the group consisting of glycerol-2-phosphate, sn-glycerol 3-phosphate and L-glycerol-3-phosphate salt, or a mixture thereof.

8. A composition according to claim 1, wherein said molecule is a salt of a sugar selected from the group consisting of mono-phosphate dibasic salt, mono-sulfonate salt, mono-sulfate salt and mono-carboxylate salt of a sugar, said sugar being selected from the group consisting of fructose, galactose, ribose, glucose, xylose, rhamnulose, sorbose, erythrulose, deoxy-ribose, ketose, mannose, arabinose, fuculose, fructopyranose, ketoglucose, sedoheptulose, trehalose, tagatose, sucrose, allose, threose, xylulose, hexose, methylthio-ribose, and methylthio-deoxy-ribulose, or a mixture thereof.

9. A composition according to claim 1, wherein said molecule is selected from the group consisting of sodium, magnesium or iron salt of glycerol-2-phosphate, sn-glycerol-3-phosphate and L-glycerol-3-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-phosphate and fructose-6-phosphate, or a mixture thereof.

10. A composition according to claim 1, wherein said molecule is selected from the group consisting of N-[carbamoylmethyl]-2-aminoethane sulfonate (ACES), N,N-bis[2-hydroxyethyl]-2-aminoethane sulfonate (BES), 3-[N,N-bis(2-hydroxy-ethyl)amino]-2-hydroxypropanesulfonate (DIPSO), N-[2-hydroxyethyl]piperazine-N′

-3-propane-sulfonate (EPPS), N-[2-hydroxyethyl]piperazine-N′

-4-butane-sulfonate (HEPBS), N-[2-hydroxyethyl]piperazine-N′

-2-ethanesulfonate (HEPES), N-[2-hydroxyethyl]piperazine-N′

-2-hydroxypropanesulfonate (HEPSO), 2-[N-morpholino]ethanesulfonate (MES), 4-[N-morpholino]butanesulfonate (MOBS), 3-[N-morpholino]propanesulfonate (MOPS), 3-[N-morpholino]-2-hydroxypropanesulfonate (MOPSO), piperazine-N,N′

-bis[2-ethanesulfonate] (PIPES), piperazine-N,N′

-bis[2-hydroxypropanesulfonate] (POPSO), 3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonate (TAPSO), and N-tris [hydroxymethyl]methyl-2-aminoethanesulfonate (TES), and derivatives or mixtures thereof.

11. A composition according to claim 1, wherein said molecule is selected from the group consisting of N,N-bis[hydroxyethyl]glycine (BICINE), bis[2-hydroxyethyl]iminotris [hydroxymethyl]methane (BIS-TRIS), Glycyl-glycine (GLY-GLY), Triethanolamine (TEA), N-tris[hydroxymethyl]methylglycine (TRICINE), and Tris [hydroxymethyl]aminomethane (TRIZMA), and derivatives or mixtures thereof.

12. A composition according to claim 1, wherein said molecule has either one acid group and at least one amino group, or more amino groups than acid groups.

13. A composition according to claim 1, wherein said molecule is an amino-acid residue, an amino-acid sequence or a poly(amino acids) having a basic character and a pKa between 6.0 and 8.4.

14. A composition according to claim 13, wherein said amino acid residue is selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), asparagine (ASN), and glutamine (GLN), or a mixture thereof.

15. A composition according to claim 1, wherein said molecule is an amino acid residue or amino acid derivative selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), and glutamine (GLN), said amino acid residue or amino acid derivative being modified with a radical acetyl, t-butyl, benzyl, benzoyl, ethyl, formyl, or methyl.

16. A composition according to claim 1, wherein said molecule is a sequence, derivative or polymer of at least one amino acid selected from the group consisting of alanine (ALA), histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), glutamine (GLN), glycine (GLY), hydroxyproline (HYP), isoleucine (ILE), leucine (LEU), norleucine (NLE), phenylalanine (PHE), proline (PRO), serine (SER), threonine (THR), tyrosine (TYR), and valine (VAL).

17. A composition according to claim 1, wherein said composition further comprises at least one other water-soluble polymer other than chitosan.

18. A composition according to claim 1, wherein said at least one other polymer is selected from the group consisting of collagen, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl propylcellulose, hydroxymethyl propyl cellulose, polyethylene oxide, polypropylene oxide, poly(ethylene oxide-co-propylene oxide) copolymers, poly(ethylene oxide-co-propylene oxide-co-ethylene oxide) copolymers, polyvinyl alcohol, and polycaprolactone diols, and derivatives or mixtures thereof.

19. A composition according to claim 1, further comprising a solid particulate or a water-soluble additive.

20. A composition according to claim 1, further comprising a drug or a pharmaceutical agent.

21. A composition according to claim 1, further comprising microorganisms, plant cells, animal cells or human cells dispersed therein.

22. A composition according to claim 1, for use as a carrier for delivering a pharmaceutical agent in situ.

23. A method for preparing a composition according to claim 1, which comprises the steps of:

a) dissolving a pH-gelling acid-soluble polymer within an aqueous acidic solution of a pH from about 1.0 to about 5.0 to obtain an aqueous polymer composition having a concentration of 0.1 to 10% by weight of said polymer, said polymer being free of chitosan and chitosan derivatives;

b) dissolving 0.1 to 10% by weight of a water-soluble molecule having a basic character and a pKa between 6.0 and 8.4 within said aqueous polymer composition to obtain a clear liquid formulation with a pH ranging between 5.8 and 7.4;

c) heating said liquid formulation at a temperature above 30°

C. to obtain a solid gel, said gel having a pH from about 5.8 to about 7.4.

24. The method of claim 23, wherein said aqueous acidic solution is prepared from an organic or inorganic acid selected from the group consisting of acetic acid, ascorbic acid, glutamic acid, lactic acid, lactobionic acid, salicylic acid, phosphoric acid, hydrochloric acid, propionic acid, and formic acid, or a mixture thereof.

25. The method of claim 23, wherein said molecule is an organic salt selected from the group consisting of a mono-phosphate salt, a mono-sulfonate salt, a mono-sulfate salt and a mono-carboxylate salt.

26. The method of claim 23, wherein said molecule is a salt of polyol selected from the group consisting of a mono-phosphate dibasic salt, a mono-sulfonate salt, a mono-sulfate salt and a mono-carboxylate salt of polyol, said polyol being selected from the group consisting of glycerol, histidinol, acetol, diethylstil-bestrol, indole-glycerol, sorbitol, ribitol, xylitol, arabinitol, erythritol, inositol, mannitol, glucitol, palmitoyl-glycerol, linoleoyl-glycerol, oleoyl-glycerol, and arachidonoyl-glycerol, or a mixture thereof.

27. The method of claim 26, wherein said salt of glycerol is selected from the group consisting of glycerol-2-phosphate, sn-glycerol 3-phosphate and L-glycerol-3-phosphate salts, or a mixture thereof.

28. The method of claim 23, wherein said molecule is a salt of sugar selected from the group selected from a mono-phosphate dibasic salt, a mono-sulfonate salt, a mono-sulfate salt and a mono-carboxylate salt of sugar, said sugar being selected from the group consisting of fructose, galactose, ribose, glucose, xylose, rhamnulose, sorbose, erythrulose, deoxy-ribose, ketose, mannose, arabinose, fuculose, fructopyranose, ketoglucose, sedoheptulose, trehalose, tagatose, sucrose, allose, threose, xylulose, hexose, methylthio-ribose, and methylthio-deoxy-ribulose, or a mixture thereof.

29. The method of claim 23, wherein said molecule is a sodium, magnesium or iron salt of glycerol-2-phosphate, sn-glycerol-3-phosphate and L-glycerol-3-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-phosphate or fructose-6-phosphate, or a mixture thereof.

30. The method of claim 23, wherein said molecule is selected from the group consisting of N-[carbamoylmethyl]-2-aminoethane sulfonate (ACES), N,N-bis[2-hydroxyethyl]-2-aminoethane sulfonate (BES), 3-[N,N-bis(2-hydroxy-ethyl)amino]-2-hydroxypropanesulfonate (DIPSO), N-[2-hydroxyethyl]piperazine-N′

-3-propane-sulfonate (EPPS), N-[2-hydroxyethyl]piperazine-N′

-4-butane-sulfonate (HEPBS), N-[2-hydroxyethyl]piperazine-N′

-2-ethanesulfonate (HEPES), N-[2-hydroxyethyl]piperazine-N′

-2-hydroxypropanesulfonate (HEPSO), 2-[N-morpholino]ethanesulfonate (MES), 4-[N-morpholino]butanesulfonate (MOBS), 3-[N-morpholino]propanesulfonate (MOPS), 3-[N-morpholino]-2-hydroxypropanesulfonate (MOPSO), piperazine-N,N′

-bis[2-ethanesulfonate] (PIPES), piperazine-N,N′

-bis[2-hydroxypropanesulfonate] (POPSO), 3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonate (TAPSO), and N-tris [hydroxymethyl]methyl-2-aminoethanesulfonate (TES), and derivatives or mixtures thereof.

31. The method of claim 23, wherein said molecule is selected from the group consisting of N,N-bis[hydroxyethyl]glycine (BICINE), bis[2-hydroxyethyl]iminotris [hydroxymethyl]methane (BIS-TRIS), Glycyl-glycine (GLY-GLY), Triethanolamine (TEA), N-tris[hydroxymethyl]methylglycine (TRICINE), and Tris [hydroxymethyl]aminomethane (TRIZMA), and derivatives or mixtures thereof.

32. The method of claim 23, wherein said molecule has either one acid group and at least one amino group, or more amino groups than acid groups.

33. The method of claim 23, wherein said molecule is an amino-acid residue, an amino-acid sequence or a poly(amino acids) having a basic character and a pKa between 6.0 and 8.4.

34. The method of claim 33, wherein said amino acid residue is selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), asparagine (ASN), glutamine (GLN), or a mixture thereof.

35. The method of claim 33, wherein said molecule is an amino acid residue or amino acid derivative selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), and glutamine (GLN) modified with a radical acetyl, t-butyl, benzyl, benzoyl, ethyl, formyl, or methyl.

36. The method of claim 23, wherein said molecule is a sequence, derivative or polymer of at least one amino acid selected from the group consisting of alanine (ALA), histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), glutamine (GLN), glycine (GLY), hydroxyproline (HYP), isoleucine (ILE), leucine (LEU), norleucine (NLE), phenylalanine (PHE), proline (PRO), serine (SER), threonine (THR), tyrosine (TYR), and valine (VAL).

37. The method of claim 23, wherein said aqueous polymer composition turns into a gel at a temperature above 10°

C.

38. The method of claim 23, wherein said aqueous polymer composition turns into a gel at a temperature above 37°

C.

39. The method of claim 23, wherein said polymer solution further comprises a solid particulate additive, said solid particulate additive being added to the polymer solution of step a) or b).

40. The method of claim 23, further comprising another water-soluble polymer added to the polymer solution of step a) or b), said other water-soluble polymer being free of chitosan and chitosan derivatives.

41. The method of claim 40, wherein said other polymer is selected from the group consisting of collagen, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl propylcellulose, hydroxymethyl propyl cellulose, polyethylene oxide, polypropylene oxide, poly(ethylene oxide-co-propylene oxide) copolymers, poly(ethylene oxide-co-propylene oxide-co-ethylene oxide) copolymers, polyvinyl alcohol, and polycaprolactone diols, or derivatives thereof.

42. The composition of claim 1, wherein said composition is loaded with cells selected from the group consisting of chondrocytes (articular cartilage), fibrochondrocytes (meniscus), ligament fibroblasts (ligament), skin fibroblasts (skin), tenocytes (tendons), myofibroblasts (muscle), mesenchymal stem cells and keratinocytes (skin).

43. A polymeric liquid aqueous composition for producing self-gelling systems and gels, which comprises:

a) an acidic water-based medium; and

b) 0.1 to 10% by weight of a Ph-gelling acid-soluble polymer; and

c) 0.1 to 10% by weight of a water-soluble molecule having a basic character and a pKa between 6.0 and 8.4, said water-soluble molecule being free of salt of polyol and sugar;

wherein said liquid composition has a final Ph ranging from 5.8 and 7.4, and forms a stable solid and homogeneous gel when heated within a temperature range from 10 to 70°

C.

44. A composition according to claim 43, wherein said composition is prepared from organic and/or inorganic acid.

45. A composition according to claim 44, wherein the organic and/or inorganic acid is selected from the group consisting of hydrochloric acid, citric acid, ascorbic acid, lactic acid, lactobionic acid, acetic acid, salicylic acid, formic acid, glutamic acid, phosphoric acid, orthophosphoric acid, and glycerophosphoric acid, or a mixture thereof.

46. A composition according to claim 43, wherein said polymer comprises a Ph-gelling acid-soluble polysaccharide, polypeptidic or poly(amino acids), or synthetic polymer.

47. A composition according to claim 43, wherein said polymer comprises a solution of chitosan, modified chitosan or chitosan derivative, said solution of chitosan being cationic and bearing amino groups.

48. A composition according to claim 43, wherein said molecule is an organic salt selected from the group consisting of mono-phosphate salt, mono-sulfonate salt, mono-sulfate salt and mono-carboxylate salt.

49. A composition according to claim 43, wherein said molecule is selected from the group consisting of N-[carbamoylmethyl]-2-aminoethane sulfonate (ACES), N,N-bis[2-hydroxyethyl]-2-aminoethane sulfonate (BES), 3-[N,N-bis(2-hydroxy-ethyl)amino]-2-hydroxypropanesulfonate (DIPSO), N-[2-hydroxyethyl]piperazine-N′

-3-propane-sulfonate (EPPS), N-[2-hydroxyethyl]piperazine-N′

-4-butane-sulfonate (HEPBS), N-[2-hydroxyethyl]piperazine-N′

-2-ethanesulfonate (HEPES), N-[2-hydroxyethyl]piperazine-N′

-2-hydroxypropanesulfonate (HEPSO), 2-[N-morpholino]ethanesulfonate (MES), 4-[N-morpholino]butanesulfonate (MOBS), 3-[N-morpholino]propanesulfonate (MOPS), 3-[N-morpholino]-2-hydroxypropanesulfonate (MOPSO), piperazine-N,N′

-bis[2-ethanesulfonate] (PIPES), piperazine-N,N′

-bis[2-hydroxypropanesulfonate] (POPSO), 3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonate (TAPSO), and N-tris [hydroxymethyl]methyl-2-aminoethanesulfonate (TES), and derivatives or mixtures thereof.

50. A composition according to claim 43, wherein said molecule is selected from the group consisting of N,N-bis[hydroxyethyl]glycine (BICINE), bis[2-hydroxyethyl]iminotris [hydroxymethyl]methane (BIS-TRIS), Glycyl-glycine (GLY-GLY), Triethanolamine (TEA), N-tris[hydroxymethyl]methylglycine (TRICINE), and Tris [hydroxymethyl]aminomethane (TRIZMA), and derivatives or mixtures thereof.

51. A composition according to claim 43, wherein said molecule has either one acid group and at least one amino group, or more amino groups than acid groups.

52. A composition according to claim 43, wherein said molecule is an amino-acid residue, an amino-acid sequence or a poly(amino acids) having a basic character and a pKa between 6.0 and 8.4.

53. A composition according to claim 52, wherein said amino acid residue is selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), asparagine (ASN), and glutamine (GLN), or a mixture thereof.

54. A composition according to claim 43, wherein said molecule is an amino acid residue or amino acid derivative selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), and glutamine (GLN), said amino acid residue or amino acid derivative being modified with a radical acetyl, t-butyl, benzyl, benzoyl, ethyl, formyl, or methyl.

55. A composition according to claim 43, wherein said molecule is a sequence, derivative or polymer of at least one amino acid selected from the group consisting of alanine (ALA), histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), glutamine (GLN), glycine (GLY), hydroxyproline (HYP), isoleucine (ILE), leucine (LEU), norleucine (NLE), phenylalanine (PHE), proline (PRO), serine (SER), threonine (THR), tyrosine (TYR), and valine (VAL).

56. A composition according to claim 43, wherein said composition further comprises at least one other water-soluble polymer.

57. A composition according to claim 43, wherein said at least one other polymer is selected from the group consisting of collagen, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl propylcellulose, hydroxymethyl propyl cellulose, polyethylene oxide, polypropylene oxide, poly(ethylene oxide-co-propylene oxide) copolymers, poly(ethylene oxide-co-propylene oxide-co-ethylene oxide) copolymers, polyvinyl alcohol, and polycaprolactone diols, and derivatives or mixtures thereof.

58. A composition according to claim 43, further comprising a solid particulate or a water-soluble additive.

59. A composition according to claim 43, further comprising a drug or a pharmaceutical agent.

60. A composition according to claim 43, further comprising microorganisms, plant cells, animal cells or human cells dispersed therein.

61. A method for preparing a composition according to claim 43, which comprises the steps of:

a) dissolving a pH-gelling acid-soluble polymer within an aqueous acidic solution of a pH from about 1.0 to about 5.0 to obtain an aqueous polymer composition having a concentration of 0.1 to 10% by weight of said polymer;

b) dissolving 0.1 to 10% by weight of a water-soluble molecule having a basic character and a pKa between 6.0 and 8.4 within said aqueous polymer composition to obtain a clear liquid formulation with a pH ranging between 5.8 and 7.4, said water-soluble molecule being free of salt of polyol and sugar;

c) heating said liquid formulation at a temperature above 30°

C. to obtain a solid gel, said gel having a pH from about 5.8 to about 7.4.

62. The method of claim 61, wherein said aqueous acidic solution is prepared from an organic or inorganic acid selected from the group consisting of acetic acid, ascorbic acid, glutamic acid, lactic acid, lactobionic acid, salicylic acid, phosphoric acid, hydrochloric acid, propionic acid, and formic acid, or a mixture thereof.

63. The method of claim 61, wherein said polymer is a chitosan or a chitosan derivative, with a degree of deacetylation ranging from 35 to 99%.

64. The method of claim 61, wherein said molecule is an organic salt selected from the group consisting of a mono-phosphate salt, a mono-sulfonate salt, a mono-sulfate salt and a mono-carboxylate salt.

65. The method of claim 61, wherein said molecule is selected from the group consisting of N-[carbamoylmethyl]-2-aminoethane sulfonate (ACES), N,N-bis[2-hydroxyethyl]-2-aminoethane sulfonate (BES), 3-[N,N-bis(2-hydroxy-ethyl)amino]-2-hydroxypropanesulfonate (DIPSO), N-[2-hydroxyethyl]piperazine-N′

-3-propane-sulfonate (EPPS), N-[2-hydroxyethyl]piperazine-N′

-4-butane-sulfonate (HEPBS), N-[2-hydroxyethyl]piperazine-N′

-2-ethanesulfonate (HEPES), N-[2-hydroxyethyl]piperazine-N′

-2-hydroxypropanesulfonate (HEPSO), 2-[N-morpholino]ethanesulfonate (MES), 4-[N-morpholino]butanesulfonate (MOBS), 3-[N-morpholino]propanesulfonate (MOPS), 3-[N-morpholino]-2-hydroxypropanesulfonate (MOPSO), piperazine-N,N′

-bis[2-ethanesulfonate] (PIPES), piperazine-N,N′

-bis[2-hydroxypropanesulfonate] (POPSO), 3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonate (TAPSO), and N-tris [hydroxymethyl]methyl-2-aminoethanesulfonate (TES), and derivatives or mixtures thereof.

66. The method of claim 61, wherein said molecule is selected from the group consisting of N,N-bis[hydroxyethyl]glycine (BICINE), bis[2-hydroxyethyl]iminotris [hydroxymethyl]methane (BIS-TRIS), Glycyl-glycine (GLY-GLY), Triethanolamine (TEA), N-tris[hydroxymethyl]methylglycine (TRICINE), and Tris [hydroxymethyl]aminomethane (TRIZMA), and derivatives or mixtures thereof.

67. The method of claim 61, wherein said molecule has either one acid group and at least one amino group, or more amino groups than acid groups.

68. The method of claim 61, wherein said molecule is an amino-acid residue, an amino-acid sequence or a poly(amino acids) having a basic character and a pKa between 6.0 and 8.4.

69. The method of claim 68, wherein said amino acid residue is selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), asparagine (ASN), glutamine (GLN), or a mixture thereof.

70. The method of claim 68, wherein said molecule is an amino acid residue or amino acid derivative selected from the group consisting of histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), and glutamine (GLN) modified with a radical acetyl, t-butyl, benzyl, benzoyl, ethyl, formyl, or methyl.

71. The method of claim 61, wherein said molecule is a sequence, derivative or polymer of at least one amino acid selected from the group consisting of alanine (ALA), histidine (HIS), arginine (ARG), lysine (LYS), aspartic acid (ASP), glutamine (GLN), glycine (GLY), hydroxyproline (HYP), isoleucine (ILE), leucine (LEU), norleucine (NLE), phenylalanine (PHE), proline (PRO), serine (SER), threonine (THR), tyrosine (TYR), and valine (VAL).

72. The method of claim 61, wherein said aqueous polymer composition turns into a gel at a temperature above 10°

C.

73. The method of claim 61, wherein said aqueous polymer composition turns into a gel at a temperature above 37°

C.

74. The method of claim 61, wherein said polymer solution further comprises a solid particulate additive, said solid particulate additive being added to the polymer solution of step a) or b).

75. The method of claim 61, further comprising another water-soluble polymer added to the polymer solution of step a) or b).

76. The method of claim 75, wherein said other polymer is selected from the group consisting of collagen, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl propylcellulose, hydroxymethyl propyl cellulose, polyethylene oxide, polypropylene oxide, poly(ethylene oxide-co-propylene oxide) copolymers, poly(ethylene oxide-co-propylene oxide-co-ethylene oxide) copolymers, polyvinyl alcohol, and polycaprolactone diols, or derivatives thereof.

77. The composition of claim 43, wherein said composition is loaded with cells selected from the group consisting of chondrocytes (articular cartilage), fibrochondrocytes (meniscus), ligament fibroblasts (ligament), skin fibroblasts (skin), tenocytes (tendons), myofibroblasts (muscle), mesenchymal stem cells and keratinocytes (skin).