DMSO-free and Serum-free cell freezing medium has important application value in the cryopreservation of clinical grade cell products. In this paper

K562 cells were used as model cells to explore the cryoprotective effect of γ-PGA on cells in a DMSO-free and Serum-free system. The RPMI 1640 medium with glycerol content of 10% (v/v) was set as the negative control group

the fetal bovine serum with DMSO content of 10% (v/v) was set as the positive control group

the RPMI 1640 medium with glycerol content of 10% (v/v) and γ-PGA content of 0.01% (w/v) was set as the experimental group. K562 cells were suspended in the above cell freezing medium at a density of 1×106 cells/mL and placed in liquid nitrogen for 10 weeks. After resuscitation

cell recovery rate

cell morphology

and cell expansion ability of K562 were detected to analyze the cryoprotective effect of γ-polyglutamic acid on K562 cells in DMSO-Free and Serum-Free cell freezing medium. The results showed that the cell recovery rate of the experimental group was (83.00±3.00)%

which was significantly higher than that of the negative control group (70.33±5.51)% (

p

<

0.05) and the positive control group (71.00±2.65)% (

p

<

0.05); the morphology of the cells in the experimental group was intact after freezing

the average diameter and roundness of cells were basically the same before and after freezing; the cell viability after culture for 24 h after resuscitation was (88.83 ± 14.29)%

which was significantly higher than that of the negative control group (67.51±5.20)% (

p

<

0.05)

and was not significantly different from the (78.75±3.31)% of the positive control group; the lag phase in cell expansion after resuscitation was significantly shortened. It can be seen that the addition of γ-PGA to the glycerol cryopreservation system without DMSO and serum can significantly improve the cryopreservation effect of cells

and has good practical application value.