Low-Energy Electron Irradiation Inactivates Viruses in Serum and Maintains Growth-Promoting Properties in Cell...

Serum and other blood-derived products are widely used in biomedical and biopharmaceutical processes, especially for the production of vaccines or cell therapeutic applications. To ensure quality and safety, each serum lot undergoes testing for sterility to minimize the risk of disease transmission. A currently performed standard procedure is gamma-irradiation of serum for effectively killing pathogens. However, gamma irradiation can only be performed in highly shielded, specialized facilities. Low-energy electron irradiation (LEEI) is an alternative, Good Manufacturing Practice (GMP) compatible method for sterilizing serum in a standard laboratory environment.

We directly compared the sensitivity of viruses belonging to the family of flaviviruses (Zika virus and bovine viral diarrhea virus) and parvoviruses (minute virus of mice) against LEEI in 90% serum or buffer. Although the reduction is more effective in buffer than in serum, the calculated decimal reduction dose values suggest that LEEI can efficiently sterilize serum by inactivating viruses, thereby increasing product safety and extending shelf life. Furthermore, LEEI-treated serum was tested as a supplement in cell culture and showed comparable performance to nonirradiated or gamma-irradiated serum when used for the cultivation of different cell lines.

LEEI is able to inactivate viral contaminants in serum and offers significant advantages over gamma irradiation, as no large amounts of radioactivity are generated, on-site irradiation is possible, and space requirements are reduced due to fewer protective measures. These advantages allow the technology to be used in a GMP-compliant irradiation process.