Cryopreservation of umbilical cord tissue for cord tissue-derived stem cells
A method of preserving an umbilical cord is disclosed. The method comprises obtaining a segment of an umbilical cord; mincing the segment of the umbilical cord into cord tissue pieces; admixing the cord tissue pieces with a cryogenic composition comprising a cryoprotectant and a protein to form a mixture; shaking the mixture for a duration of no shorter than 20 minutes and no longer than 40 minutes; and cryopreserving the mixture.
1. A method of preserving an umbilical cord tissue, comprising:
obtaining an umbilical cord;
mincing the umbilical cord into cord tissue pieces;
treating the cord tissue pieces with a digestive enzyme solution;
admixing the cord tissue pieces with a cryogenic composition comprising a cryoprotectant and a protein to form a mixture containing the cord tissue pieces;
shaking the mixture containing the cord tissue pieces for a duration of no shorter than 20 minutes and no longer than 40 minutes; and
cryopreserving the mixture containing the cord tissue pieces.
2. The method of claim 1 , wherein each of the cord tissue pieces has a size of 2 or smaller than 2 mm.
3. The method of claim 1 , comprising shaking the mixture containing the cord tissue pieces for a duration of 25-35 minutes.
4. The method of claim 1 , wherein the shaking step is performed at a temperature below 15° C.
5. The method of claim 4 , wherein the shaking step is performed at a temperature between 0° C. and 10° C.
6. The method of claim 5 , wherein the shaking step is performed at a temperature of no greater than 4° C.
7. The method of claim 1 , wherein the shaking step is performed for a duration of 28-32 minutes.
8. The method of claim 1 , wherein each of the cord tissue pieces has a size of no larger than 2 mm and the shaking step is performed for a duration of no shorter than 28 minutes and no longer than 32 minutes.
9. The method of claim 1 , further comprising adding an enzyme inhibitor to inhibit the digestive enzyme.
10. The method of claim 1 , wherein the cryoprotectant is at least one-selected from the group consisting of dimethyl sulfoxide (DMSO), glycerol, ethylene glycol and propylene glycol.
11. The method of claim 1 , wherein the protein component is at least one-selected from the group consisting of albumin, human serum and Plasma protein Fraction (PPF).
12. The method of claim 1 , wherein the cryogenic composition comprises:
(a) human umbilical cord blood serum 30˜50% or albumin 2.5˜25%;
(b) DMSO 5.5˜55%; and
(c) dextran 0.5˜5%.
13. A method of obtaining umbilical cord tissue-derived stem cells, comprising:
obtaining an umbilical cord;
mincing the umbilical cord into cord tissue pieces;
treating the cord tissue pieces with a digestive enzyme solution;
admixing the cord tissue pieces with a cryogenic composition comprising a cryoprotectant and a protein to form a mixture containing the cord tissue pieces;
shaking the mixture containing the cord tissue pieces for a duration of no shorter than 20 minutes and no longer than 40 minutes; and
cryopreserving the mixture containing the cord tissue pieces;
thawing the mixture containing the cord tissue pieces and removing the cryogenic composition; and
culturing the cord tissue pieces in a culture media to obtain the umbilical cord tissue- derived stem cells.
14. The method of claim 13 , wherein the culture media comprises human serum.
15. The method of claim 13 , wherein each of the cord tissue pieces has a size of 2 or smaller than 2 mm.
16. The method of claim 13 , comprising shaking the mixture containing the cord tissue pieces for a duration of 25-35 minutes.