ARTICLE; PHARMACEUTICAL BIOTECHNOLOGY Poly-g-glutamic acid enhances the quality of recombant erythropoietin produced by CHO cells

The effect of poly-g-glutamic acid (gPGA), which is produced by Bacillus sp., on the production of recombinant erythropoietin (rEPO) by Chinese hamster ovary (CHO) cells in suspension culture was evaluated. The growth, viability, and productivity of recombinant CHO cells were investigated in a chemically defined medium with 50 and 500 kD gPGAs at 0.075 % or with Pluronic F68. Cell growth with the two gPGAs was lower than that with Pluronic F68 but significantly higher than that without any additive (control). The effect of additives on rEPO productivity was 50 kDa gPGA> 500 kDa gPGA> Pluronic F68> control. Using EPO-dependent F-36E cells, we found that the effect of additives on rEPO quality was 500 kDa gPGA> 50 kDa gPGA> control> Pluronic F68. gPGA has an enhancement effect on the quality of rEPO produced by CHO cells