Use of fluorescently-labeled nanoparticles to study pore morphology and virus capture in virus filtration membranes

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Virus filtration is a robust size-based technique that can provide the high level of viral clearance required for the production of mammalian-derived biotherapeutics such as monoclonal antibodies. Several studies have shown that the retention characteristics of some, but not all, virus filters can be significantly affected by membrane fouling, but there have been no direct measurements of how protein fouling might alter the

Section: Introductionmentioning

confidence: 99%

Impact of protein fouling on nanoparticle capture within the Viresolve® Pro and Viresolve® NFP virus removal membranes

Fallahianbijan

Giglia²,

Carbrello³

et al. 2019

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“…The 20 nm (green) nanoparticles are visible over more than 50% of the fiber wall thickness, while the 40 nm (purple) and 100 nm (red) nanoparticles are concentrated primarily at the fiber inlet (lumen side). The breadth of the capture band is likely due in part to the particle size distribution for the FluoSpheres® as discussed by Fallahianbijan et al (). A small number of 100 nm nanoparticles are clearly visible as bright spots near the filter outlet; this is discussed in more detail subsequently.…”

Section: Resultsmentioning

confidence: 97%

“…The properties of the FluoSpheres® used in this study are listed in Table . The standard deviations on the mean particle size were determined from DLS measurements (Fallahianbijan et al, ). FluoSphere® suspensions were prepared by diluting the stock solutions with 130 mM phosphate buffer (pH 7.2) to obtain a suspension containing 20 nm particles at a concentration of approximately 10 12 particles/ml, 40 nm nanoparticles at 10 11 particles/ml and 100 nm nanoparticles at 10 10 particles/ml.…”

Section: Methodsmentioning

confidence: 99%

“…Although the Planova BioEX filter was specifically developed “to achieve robust retention of parvoviruses and other small viruses under a broad range of operating conditions” (Ma et al, ), there is currently no fundamental understanding of the differences in structure/properties of the BioEX and 20N filters that give rise to this enhanced performance. The overall objective of this study was to examine the virus retention characteristics of the Planova 20N and BioEX virus filters using a combination of CLSM with fluorescently‐labeled nanoparticles (Fallahianbijan, Giglia, Carbrello, & Zydney, ) and scanning electron microscopy (SEM) with gold nanoparticles (Nazem‐Bokaee et al, ), both with similar size to viruses. The retention behavior of the Planova filters was also examined using a retrovirus under the same experimental conditions.…”

Section: Introductionmentioning

confidence: 99%

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New insights into the performance characteristics of the Planova‐series hollow‐fiber parvovirus filters using confocal and electron microscopy

Nazem‐Bokaee

Chen

O’Donnell

et al. 2019

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Virus filtration remains a critical step in the downstream process for the production of monoclonal antibodies and other mammalian cell-derived biotherapeutics. Recent studies have shown large differences in virus capture behavior of different virus filters, although the origin of these differences is still unclear. The objective of this SUPPORTING INFORMATIONAdditional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Nazem-Bokaee H, Chen D, O'Donnell SM, Zydney AL. New insights into the performance characteristics of the Planova-series hollow-fiber parvovirus filters using confocal and electron microscopy. Biotechnology and Bioengineering.

“…For example, Pang et al (2009) used casein‐coated microspheres to mimic the surface charge of MS2 phage, roughly 20 nm in size, over a large range of pH. Fallahianbijan, Giglia, Carbrello, and Zydney (2017) showed that 20‐nm fluorescently‐labeled polystyrene latex spheres have similar capture profiles as model viruses (bacteriophage) in a series of virus filtration membranes. Other investigators have used similar nanospheres as models to study bacteriophage transport through microfiltration membranes (Pontius, Amy, & Hernandez, 2009) and in various water treatment systems (Bales, Li, Yeh, Lenczewski, & Gerba, 1997; Göppert & Goldscheider, 2008).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a sterile filtration process for viral vaccines using a model nanoparticle suspension

Taylor

Kristopeit

et al. 2020

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There is growing interest in the development of new vaccines based on liveattenuated viruses (LAVs) and virus-like particles. The large size of these vaccines, typically 100-400 nm, significantly complicates the use of sterile filtration. The objectives of this study are to examine the performance of several commercial sterile filters for filtration of a cytomegalovirus vaccine candidate (referred to as the LAV) and to develop and evaluate the use of a model nanoparticle suspension to perform a more quantitative assessment. Data obtained with a mixture of 200-and 300-nm fluorescent particles provided yield and pressure profiles that captured the behavior of the viral vaccine. This included the excellent performance of the Sartorius Sartobran P filter, which provided greater than 80% yield of both the vaccine and model particles even though the average particle size was more than 250 nm. The particle yield for the Sartobran P was independent of filtrate flux above 200 L/m 2 /h, but increased with increasing particle concentration, varying from less than 10% at concentrations around 10 7 particles/ml to more than 80% at concentrations above 10 10 particles/ml due to saturation of particle capture/binding sites within the filter. These results provide important insights into the factors controlling transmission and fouling during sterile filtration of large vaccine products.