Would 20 nm Filtered Fetal Bovine Serum-Supplemented Media Support Growth of CHO and HEK-293 Cells?

Abstract

Virus safety of fetal bovine serum (FBS) is a critical issue for cell culture and clinical applications of cell therapies. The size exclusion filtration of FBS-supplemented cell culture media through small-size virus retentive filter paper is presented to investigate its effect on cell culture. A substantial proportion of proteins (ca. 45%) was removed by nanofiltration, yet important transport proteins (albumin, fetuins, macroglobulins, transferrin) were unaffected. The cell viability of Chinese hamster ovary (CHO) and human embryonic kidney 293 (HEK-293) cells that were grown in media supplemented with nanofiltered FBS was surprisingly high, despite the observed protein losses. Protein depletion following nanofiltration resulted in detectable levels of autophagy markers.

Review of the Current Research on Fetal Bovine Serum and the Development of Cultured Meat

“…The components in FBS have not been fully identified, and the effects on the composition and cell culture vary depending on the individual fetus. Previously, the safety of cell cultures using FBS has been consistently stated (Gstraunthaler and van der Valkk, 2013;Manukyan et al, 2020). Cell culture using FBS may contain viruses, mycoplasma, endotoxin and prion proteins, and these controversies have not been clearly resolved (Merten, 2002;Gstraunthaler and van der Valkk, 2013;Manukyan et al, 2020).…”

“…Previously, the safety of cell cultures using FBS has been consistently stated (Gstraunthaler and van der Valkk, 2013;Manukyan et al, 2020). Cell culture using FBS may contain viruses, mycoplasma, endotoxin and prion proteins, and these controversies have not been clearly resolved (Merten, 2002;Gstraunthaler and van der Valkk, 2013;Manukyan et al, 2020). For this reason, the production of cultured meat using FBS has not been verified for human safety for repeated production and ingestion of the culture.…”

Differentiation of human pluripotent stem cells into insulin-producing islet-like clusters using nanofiltered cell culture medium

“…The manufacturing of the 20 nm cut-off nanocellulose based filter paper (33 μm in thickness) was done as reported earlier (Wu et al, 2019;Manukyan et al, 2020). The particle rejection capacity of the nanocellulose based filter paper was verified using model tracer particles, such as 20 nm Au NPs and IgG protein with dynamic light scattering (DLS) and UV-vis spectroscopy (Gustafsson et al, 2018;Wu et al, 2019).…”

“…The use of virus-barrier filters for upstream processing of cell culture media components received increased attention from both commercial vendors (Liu et al, 2000;Mann et al, 2015;Barro et al, 2020) and academic groups (Manukyan et al, 2019;Manukyan et al, 2020). While virus filtration of cell culture media is a robust method of virus clearance, the suitable filters are prone to clogging by protein aggregates and may deplete basal media components from the medium, which could negatively affect cell differentiation.…”