Tangential Flow Filtration for the Concentration of Oncolytic Measles Virus: The Influence of Filter Properties and the Cell Culture Medium

Abstract

The therapeutic use of oncolytic measles virus (MV) for cancer treatment requires >108 infectious MV particles per dose in a highly pure form. The concentration/purification of viruses is typically achieved by tangential flow filtration (TFF) but the efficiency of this process for the preparation of MV has not been tested in detail. We therefore investigated the influence of membrane material, feed composition, and pore size or molecular weight cut-off (MWCO) on the recovery of MV by TFF in concentration mode. We achieved the recovery of infectious MV particles using membranes with a MWCO ≤ 300 kDa regardless of the membrane material and whether or not serum was present in the feed. However, serum proteins in the medium affected membrane flux and promoted fouling. The severity of fouling was dependent on the membrane material, with the cellulose-based membrane showing the lowest susceptibility. We found that impurities such as proteins and host cell DNA were best depleted using membranes with a MWCO ≥ 300 kDa. We conclude that TFF in concentration mode is a robust unit operation to concentrate infectious MV particles while depleting impurities such as non-infectious MV particles, proteins, and host cell DNA.

Isolation of Extracellular Vesicles From Microalgae: A Renewable and Scalable Bioprocess

“…These methods include density gradient ultracentrifugation (gUC), filtration, and various chromatographies (Staubach et al, 2021), such as size exclusion chromatography (SEC), ion exchange chromatography (IEX), and affinity chromatography (AC) (Paganini et al, 2019). A reliable method extensively used for liposomes (Worsham et al, 2019) as well as for virus isolation (Loewe et al, 2019) and now adopted in the EV field is tangential flow filtration (TFF) (Heinemann et al, 2014;Busatto et al, 2018;Haraszti et al, 2018). In TFF, the particle solution, or the cell culture, flows tangentially over a membrane with a given size cut-off.…”

Recovery and Purification of Protein Aggregates From Cell Lysates Using Ceramic Membranes: Fouling Analysis and Modeling of Ultrafiltration

“…Resistance-in-series analysis considers the total filtration resistance as the sum of all partial resistances of different causes, here defined as membrane resistance (R M ), gel layer resistance caused by concentration polarization of protein aggregates (R g ), and adsorption resistance from the adsorption of cell lysate proteins to the membrane (R a ). This model has been successfully applied to the filtration of biological solutions containing cells (Fan et al, 2015), viruses (Loewe et al, 2019), and enzymes (Fan et al, 2020). Different approaches to applying resistance-in-series have recently been reviewed extensively (Di Bella and Di Trapani, 2019).…”

Virus recovery by tangential flow filtration: A model to guide the design of a sample concentration process

“…Very high values of water recovery are likely to lead to membrane fouling and related virus losses. By the same token, if low r is a result of increasing crossflow rate (e.g., to combat fouling) while maintaining the same permeate flow rate, one can reach shear stresses in the membrane channel that may damage fragile biologics such as enveloped viruses 23‐25 . For example, Grein et al have shown that Measles virus titers are sensitive to shear, with shear stress of 0.25 Pa and higher reducing the virus titer by more than four orders of magnitude 26 …”