CONTROLLED-VISCOSITY POLYMERIC HYDROGEL AND METHOD FOR MAKING IT

Abstract

A controlled-viscosity polymeric hydrogel including an aqueous solvent, a water-soluble synthetic polymeric component and an anti-cross-linking component, constituted of a polyphenol, in particular of hydroxytyrosol.

Claims

1. A controlled-viscosity polymeric hydrogel, comprising an aqueous solvent, a water-soluble synthetic polymeric component and an anti-cross-linking component, wherein the aqueous solvent has a pH of less than 6 and that the anti-cross-linking component is constituted of a polyphenol.

2. The hydrogel according to claim 1, wherein the polyphenol is hydroxytyrosol or another polyphenolic derivative.

3. The hydrogel according to claim 1, wherein the polyphenol is oleuropein, tyrosol, oleocanthal and/or oleacein.

4. The hydrogel according to claim 1, wherein the water-soluble synthetic polymeric component has an average molecular weight of between 300 and 10,000,000 g/mol.

5. The hydrogel according to claim 1, wherein the water-soluble synthetic polymeric component has an average molecular weight of between 1,000 and 3,000,000 g/mol.

6. The hydrogel according to claim 1, wherein the concentration of the polyphenol is equal to or less than 100 mM.

7. The hydrogel according to claim 1, wherein the concentration of the polyphenol is equal to or less than 50 mM.

8. The hydrogel according to claim 1, wherein the quantity by weight of the water-soluble synthetic polymeric component is between 1% and 30% of the total weight of the hydrogel.

9. The hydrogel according to one of the preceding claims, characterised in that it comprises collagen peptides, so as to increase its regenerative and anti-inflammatory capacity.

10. The hydrogel according to claim 1, wherein it comprises bacteriocins, so as to increase its antimicrobial capacity.

11. The hydrogel according to claim 9, wherein collagen peptides have a molecular weight equal to or less than 5,000 g/mol.

12. The hydrogel according to claim 9, wherein collagen peptides have a molecular weight equal to or less than 3,000 g/mol.

13. The hydrogel according to claim 9, wherein the concentration of collagen peptides is equal to or less than 50 mg/ml.

14. The hydrogel according to claim 9, wherein the concentration of collagen peptides is equal to or less than 25 mg/ml.

15. The hydrogel according to claim 10, wherein it comprises class I bacteriocins, including Nisin A, Nisin F and/or Nisin Z.

16. The hydrogel according to claim 10, wherein the concentration of bacteriocins is equal to or less than 10 mM.

17. The hydrogel according to claim 10, wherein the concentration of bacteriocins is equal to or less than 5 mM.

18. The hydrogel according to claim 1, wherein the water-soluble synthetic polymeric component is selected from a group comprising a polymer and/or polymeric mixtures and/or copolymers of ethylene oxide (PEG, PEO, POE), vinyl alcohol, vinyl pyrrolidone.

19. A method for making a controlled-viscosity polymeric hydrogel, wherein it comprises the following steps: rehydration of a synthetic polymeric component in aqueous solution with a pH of less than 6; addition of a polyphenol additive to the solution; irradiation of the solution with an electromagnetic radiation having a frequency within the frequency spectrum of ß rays or of γ rays; polymerization of the hydrogel, limited by the antioxidant property of the polyphenol.

20. The method according to claim 19, wherein polyphenol is selected from a group comprising hydroxytyrosol or another polyphenolic derivative, oleuropein, tyrosol, oleocanthal, oleacein.

Description

PREFERRED EMBODIMENTS OF THE INVENTION

[0028] A controlled-viscosity polymeric hydrogel comprises an aqueous solvent with a pH of less than 6, a water-soluble synthetic polymeric component and an anti-cross-linking component, wherein the anti-cross-linking component is constituted of a polyphenol, preferably of hydroxytyrosol or another polyphenolic derivative, such as, for example, oleuropein and tyrosol, but also oleocanthal and/or oleacein.

[0029] In the method for making the controlled-viscosity hydrogel, after having rehydrated the synthetic polymeric component in aqueous solution having a pH of less than 6, the solution has added to it as an additive hydroxytyrosol (or its derivative), or another polyphenol.

[0030] Hydroxytyrosol is a plant chemical compound present in olive oil: it and its derivatives are used here because of the very high antioxidant power, that is to say, because of the capacity to capture the free radicals which form as a result of some electrochemical reactions. In this case, when the solution is irradiated with an electromagnetic radiation preferably having a frequency within the frequency spectrum of ß rays or of γ rays, the hydroxytyrosol limits the polymerization process, capturing the polymer radical species in such a way as to control the final viscosity of the sterilized hydrogel.

[0031] Based on the final viscosity, the hydrogel obtained may be used in the tissue regeneration sphere and in the treatment of connective tissue infections: the presence of the hydroxytyrosol accounts for the anti-inflammatory and regenerative properties which the hydrogel may have once implanted, in particular in epithelial, connective, muscular and nerve tissues.

[0032] Strengthening of the regenerative and anti-inflammatory power of the hydrogel may be achieved thanks to the addition of collagen peptides, for example of bovine origin, which are capable of stimulating new collagen synthesis, in particular for bone, cartilage, tendons, ligaments and skin; the increase in the antimicrobial potential may in contrast be achieved with the addition as additives of bacteriocins, in particular of class I, which are particularly effective against antibiotic-resistant pathogens.

[0033] The water-soluble synthetic polymeric component is selected from a group comprising a polymer and/or polymeric mixtures and/or copolymers of ethylene oxide (PEG, PEO, POE), vinyl alcohol, vinyl pyrrolidone, its average molecular weight is between 300 and 10,000,000 g/mol, and preferably between 1,000 and 3,000,000 g/mol, and its quantity by weight is between 1% and 30% of the total weight of the hydrogel.

[0034] The concentration of hydroxytyrosol is equal to or less than 100 mM, and preferably equal to or less than 50 mM.

[0035] The collagen peptides have a molecular weight equal to or less than 5,000 g/mol, and preferably equal to or less than 3,000 g/mol, their concentration is equal to or less than 50 mg/ml, and preferably equal to or less than 25 mg/ml.

[0036] The class I bacteriocins, which include Nisin A, Nisin F and/or Nisin Z, have a concentration equal to or less than 10 mM, and preferably equal to or less than 5 mM.