Optimization of Key Factors in Serum Free Medium for Production of Human Recombinant GM-CSF Using Response Surface Methodology

Researchers add serum to a classical medium at concentrations of 5 to 10% (v/v) to grow cellsin-vitro culture media. Unfortunately, serum is a poorly defined culture medium componentas its composition can vary considerably while serum-free cell culture media are an excellentalternative to standard serum-containing media and offer several major advantages. Advantagesof using serum-free media include a lower risk of infectious agents, lower risk of interferingcomponents, less contaminant, avoids ethical issues. According to previous studies insulin,selenium, transferrin and glucose are important component of serum that affect cell growth. Inthe present study, we optimized amount of these factors in order to serum free culture mediumfabrication. Response surface methodology (RSM) was employed for optimization of key factorsin serum free medium to enhance recombinant human GM-CSF (rhGM-CSF) production in CHOcell line. Four important process parameters including insulin concentration (0-2 g/L), transferrinconcentration (0-1 g/L), selenium concentration (0-0.001 g/L) and glucose concentration (0-5g/L) were optimized to obtain the best response of rhGM-CSF production using the statisticalBox–Behnken design. The experimental data obtained were analyzed by analysis of variance(ANOVA) and fitted to a second-order polynomial equation using multiple regression analysis.Numerical optimization applying desirability function was used to identify the optimumconditions for maximum production of rhGM-CSF. The optimum conditions were found to beinsulin concentration = 1.1 g/L, transferrin concentration = 0.545 g/L, selenium concentration =0.000724 g/L and glucose = 1. 4 g/L. Maximum rhGM-CSF production was found to be 3.5 g/L.