Cryoprotecting agent, cryoprotecting and cryopreserved compositions, uses thereof, and methods of cryopreservation

1. A method of protecting a sample from freezing damage, comprising the steps of:

(i) bringing a sample comprising peripheral blood derived hematopoietic stem cells to be cryopreserved into contact with a cryoprotective medium comprising a cryoprotecting agent to obtain a cryopreservation composition;

(ii) subsequently reducing the temperature of the cryopreservation composition to a cryopreservation temperature,

where said cryoprotecting agent comprises one or more cryoprotectants selected from isomaltooligosaccharide and hydrogenated isomaltooligosaccharide,

wherein said one or more cryoprotectants has a weight average molecular weight (Mw) of between 850 and 1,150 Da, and the cryoprotective composition is substantially free of dimethyl sulfoxide (DMSO).

2. The method according to claim 1 , wherein at least one of the one or more cryoprotectants has a polydispersity of ≥1 and ≤5.

3. The method according to claim 1 , wherein said one or more cryoprotectants is an isomaltooligosaccharide having a weight average molecular weight (Mw) of between 850 and 1,150 Da.

4. The method according to claim 1 , wherein said one or more cryoprotectants is an hydrogenated isomaltooligosaccharide having a weight average molecular weight (Mw) of between 850 and 1,150 Da.

5. The method according to claim 1 , wherein the weight fraction of isomaltooligosaccharides in the cryoprotective medium having less than 3 glucose units is less than 15% w/w and/or wherein the weight fraction of isomaltooligosaccharides in the cryoprotective medium having more than 9 glucose units is less than 20% w/w.

6. The method according to claim 1 , wherein said isomaltooligosaccharides and hydrogenated isomaltooligosaccharides are dextran-based.

7. The method according to claim 1 , wherein said cryoprotecting agent is in the form of a powder or in the form of a solution.

8. The method according to claim 1 , wherein said cryoprotecting agent comprises from 30% to 70% w/w of said one or more cryoprotectants.

9. The method according to claim 1 , wherein said cryoprotecting agent comprises an additional cryoprotectant, wherein said additional cryoprotectant is ethylene glycol.

10. The method according to claim 1 , wherein said cryoprotecting agent comprises an additional cryoprotectant, wherein said additional cryoprotectant is albumin.

11. The method according to claim 1 , wherein the sample consists of hematopoietic stem cells.

12. The method of claim 1 , wherein the peripheral blood derived hematopoietic stem cells are CD34 positive blood stem cells.

13. The method of claim 1 , further comprising

(iii) thawing the sample after cryopreservation to generate a thawed sample;

(iv) directly suspending the thawed sample in a culture medium; and

(v) culturing the thawed sample in the culture medium,

wherein the method does not include washing the thawed sample prior to suspending or prior to culturing the thawed sample in the culture medium.

14. The method according to claim 1 , wherein said sample comprises in vitro cultured hematopoietic stem cells.

15. The method according to claim 1 , wherein said sample is suitable for use in hematopoietic stem cells transplantation.

16. A method of protecting a sample from freezing damage, comprising the steps of:

(i) bringing a sample comprising peripheral blood derived hematopoietic stem cells to be cryopreserved into contact with a cryoprotective medium comprising a cryoprotecting agent to obtain a cryopreservation composition;

(ii) subsequently reducing the temperature of the cryopreservation composition to a cryopreservation temperature, where said cryoprotecting agent comprises one or more cryoprotectants selected from isomaltooligosaccharides and hydrogenated isomaltooligosaccharides,

wherein said one or more cryoprotectants has a weight average molecular weight (Mw) of between 850 and 1,150 Da, the cryoprotective composition is substantially free of dimethyl sulfoxide (DMSO), and said cryoprotecting agent further comprises an additional cryoprotectant, which additional cryoprotectant is albumin, wherein said cryoprotective medium comprises no more than 8% w/w albumin.

17. The method according to claim 16 , wherein said cryoprotective medium comprises from 1-8% albumin.

18. The method according to claim 16 , wherein said cryoprotective medium comprises no more than 5% w/w albumin.

19. The method according to claim 16 , wherein said cryoprotective medium comprises from 1-4% w/w albumin.

20. The method according to claim 16 , wherein at least one of said one or more cryoprotectants has a polydispersity of ≥1 and ≤5.

21. The method according to claim 16 , wherein said cryoprotectants selected from isomaltooligosaccharides and hydrogenated isomaltooligosaccharides consist of isomaltooligosaccharides having a weight average molecular weight (Mw) of between 850 and 1,150 Da.

22. The method according to claim 16 , wherein said cryoprotectants selected from isomaltooligosaccharides and hydrogenated isomaltooligosaccharides consist of hydrogenated isomaltooligosaccharides having a weight average molecular weight (Mw) of between 850 and 1,150 Da.

23. The method according to claim 16 , wherein the weight fraction of isomaltooligosaccharides in the cryoprotective medium having less than 3 glucose units is less than 15% w/w and/or wherein the weight fraction of isomaltooligosaccharides in the cryoprotective medium having more than 9 glucose units is less than 20% w/w.

24. The method according to claim 16 , wherein said isomaltooligosaccharides and hydrogenated isomaltooligosaccharides are dextran-based.

25. The method according to claim 16 , wherein said cryoprotecting agent is in the form of a powder or in the form of a solution.

26. The method according to claim 16 , wherein said cryoprotecting agent comprises from 30% to 70% w/w of said one or more cryoprotectants.

27. The method according to claim 16 , wherein the sample consists of hematopoietic stem cells.

28. The method according to claim 16 , wherein the peripheral blood derived hematopoietic stem cells are CD34 positive blood stem cells.

29. The method according to claim 16 , further comprising

(iii) thawing the sample after cryopreservation to generate a thawed sample;

(iv) directly suspending the thawed sample in a culture medium; and

(v) culturing the thawed sample in the culture medium, wherein the method does not include washing the thawed sample prior to suspending or prior to culturing the thawed sample in the culture medium.

30. The method according to claim 16 , wherein said sample comprises in vitro cultured hematopoietic stem cells.

31. The method according to claim 16 , wherein said sample is suitable for use in hematopoietic stem cells transplantation.