received by the International Bureau on 14 October 2019 (14.10.19)

1. A method for decellularizing corneal extracellular matrix, comprising the steps of:

a. treating corneal extracellular matrix with one or more agents selected from a group comprising sodium dodecyl sulfate, Triton X-100, sodium chloride, sodium deoxycholate, 3-[(3-Cholamidopropyl) dime thy lammonio]- 1 -propanesulfonate, trypsin, EDTA, sulfobetaines-lO, sulfobetaines- 16, nuclease, protease, collagenase, lipase, thermolysin, a-galactosidase, Tri(n-butyl) phosphate, glycerol, isopropanol, ethanol and methanol; and

b. treating the corneal extracellular matrix obtained in step (a) with RNase and DNase to obtain decellularized corneal extracellular matrix.

2. The method as claimed in claim 1, wherein sodium dodecyl sulfate or Triton X-100 is present at a concentration in a range from 0.1% to 3% w/v.

3. The method as claimed in claim 1, wherein sodium chloride is present at a concentration in a range from 0.001 M to 5 M.

4. The method as claimed in claim 1, wherein the concentration of RNase is in a range from 0.5 U/mL to 50 U/mL.

5. The method as claimed in claim 1, wherein the concentration of DNase is in a range from 1 U/mL to 200 U/mL.

6. The method as claimed in claim 1, wherein source of the corneal extracellular matrix is selected from a group comprising human source, caprine source, porcine source or bovine source.

7. Decellularized corneal extracellular matrix obtained by a method as claimed in claim 1.

8. A method for preparation of pre-gel or hydrogel based on corneal extracellular matrix, comprising the steps of:

a. decellularizing corneal extracellular matrix by a method as claimed in claim 1 ; b. digesting the decellularized corneal extracellular matrix using acetic acid and pepsin;

c. adjusting the pH of the digested corneal extracellular matrix in a range from 7 to 8 at a temperature below 4°C to obtain pre-gel; and

d. optionally, mixing one or more types of cells and suitable culture media with the pre-gel obtained in step (c) to obtain hydrogel.

9. The method as claimed in claim 8, wherein the concentration of acetic acid is in a range from 0.1 M to 2 M and weight of pepsin is in a range from 5% to 15% of the total weight of the decellularizing corneal extracellular matrix.

10. The method as claimed in claim 8, wherein the culture media is selected from a group comprising a-MEM, DMEM, RPMI-1640, Media-l99 and Ham’s F-12.

11. The method as claimed in claim 8, wherein the cell culture is selected from a group comprising keratocytes, epithelial cells, limbal stem cells, stromal stem cells, endothelial cells and retinal pigment epithelial cells.

12. Pre-gel obtained by a method as claimed in claim 8.

13. Hydrogel obtained by a method as claimed in claim 8.

14. Hydrogel as claimed in claim 13, optionally comprising one or more preservatives, carriers or excipients.

15. Agents selected from a group comprising sodium dodecyl sulfate, Triton X-100 and sodium chloride for use in decellularization of corneal extracellular matrix.

16. Pre-gel or hydrogel as claimed in claim 12 or claim 13 for use in treatment of corneal diseases or disorders.

17. A method of treating corneal diseases or disorders, comprising administration of pre-gel or hydrogel as claimed in claim 12 or claim 13.