Hussein, August 2007
In order to test AAGPs® effectiveness in maintaining stem cell numbers in human embryonic stem cells four samples were prepared. The first two being embryonic stem cells at high densities of 2×106 and 3×106 cells/ml which were exposed to AAGP® and the last two being embryonic stem cells at densities of 2×106 and 3x106cells/ml which had not been exposed to AAGP®. All cell populations were cryopreserved at -80°C in 20%FBS growth serum containing 10%DMSO. After 2 days of cryopreservation cells were thawed at 37°C. Population cell number was calculated using Trypan blue (4 counts per population). Cell viability/number was calculated as a percentage of cells present prior to cryopreservation.
The effectiveness of AAGP® in maintaining cell number as a percentage of cells prior to Cryopreservation was measured in mouse embryonic neural stem cells in the same way. We used both high and low densities of mouse embryonic stem cells in one cell line and a high density of mouse neural stem cells in another cell line.
Thus it can be concluded that in both high and low density cell populations of mouse embryonic stem cells and in high density populations of human embryonic stem cells the presence of AAGP® during Cryopreservation gives the cells an advantage in terms of cell survival whilst maintaining cell function/competence. It could be said that this makes AAGP® an attractive preserver in the storage of stem cells for transplants where only a low density of cells can be extracted. Though these experiments will need to be completed in other cell lines. The mechanism of this survival signal is yet to be established.