RESUMEN
Herein, a simple model setup is presented to spray fine liquid droplets containing nanoparticles in an air stream transporting this toward a filter material. The nanoparticles are made of silica and tagged with a fluorescent dye in order to render the trace of the particles easily visible. The silica nanoparticles, in a first approximation, mimic virus (severe acute respiratory syndrome coronavirus 2) particles. The setup is used to evaluate different tissues, nowadays, in times of the coronavirus pandemic, commonly used as facemasks, with regard to their particle retention capability. The setup enables adjusting different "breathing scenarios" by adjusting the gas flow speed and, thereby, to compare the filter performance for these scenarios. The effective penetration of particles can be monitored via fluorescence intensity measurements and is visualized via scanning electron micrographs and photographs under UV light. Ultimately, a strong increase of particle penetration in various mask materials as function of flow speed of the droplets is observed and an ultimate retention is only observed for FFP3 and FFP2 masks.
RESUMEN
Various mammalian cell lines are used as substrates for drug production without safety issues concerning viral contamination. However, viral contamination events in good manufacturing practice (GMP) cell culture processes, while rare, do sometimes occur. When contamination happens, it can result in serious consequences, including supply risk of life-saving drugs and substantial financial loss. To mitigate the potential risk of viral contamination, one approach taken by the industry is to implement preventative measures upstream. High-temperature short-time (HTST) treatment of culture media, at the point of use, was implemented as a virus barrier following murine minute virus (MMV) contamination. In recent years, nanofiltration, commonly used in downstream purification processes, has been evaluated for potential use as a virus barrier alternative to HTST. Several companies shared their data and experience in evaluating nanofiltration for viral barrier purpose upstream in Session 1, Part 2: Virus Barrier. These presentations are summarized below.LAY ABSTRACT: Viral contamination events in GMP cell culture processes, while rare, do sometimes occur. When contamination happens, it can result in serious consequences, including supply risk of life-saving drugs and substantial financial loss. To mitigate the potential risk of viral contamination, one approach taken by the industry is to implement preventative measures upstream. Several companies shared their data and experience in evaluating virus-retentive filtration for viral barrier purpose upstream.