Comparative Analysis of the Impact of Protein on Virus Retention for Different Virus Removal Filters.

The performance of virus filters is often determined by the extent of protein fouling, which can affect both filtrate flux and virus retention. However, the mechanisms governing changes in virus retention in the presence of proteins are still not well understood. The objective of this work was to examine the effect of proteins on virus retention by both asymmetric (Viresolve NFP and Viresolve Pro) and relatively homogeneous (Ultipor DV20 and Pegasus SV4) virus filtration membranes.

Impact of proteins and protein fouling on virus retention during virus removal filtration.

Virus filtration is a crucial step in ensuring the high levels of viral clearance required in the production of biotherapeutics produced in mammalian cells or derived from human plasma. Previous studies have reported that virus retention is often reduced in the presence of therapeutic proteins due to membrane fouling; however, the underlying mechanisms controlling this behavior are still not well understood. Experimental studies were performed with a single layer of the commercially available dual-layer Pegasus SV4 virus removal filter to more easily interpret the experimental results.

Development of a transient inline spiking system for evaluating virus clearance in continuous bioprocessing-Proof of concept for virus filtration.

The development of continuous/connected bioprocesses requires new approaches for viral clearance validation, both for specific unit operations and for the overall process. In this study, we have developed a transient inline spiking system that can be used to evaluate virus clearance at distinct time points during prolonged operation of continuous bioprocesses. The proof of concept for this system was demonstrated by evaluating the viral clearance for a virus filtration step, both with and without a prefilter upstream of the virus filter.

Effect of filtrate flux and process disruptions on virus retention by a relatively homogeneous virus removal membrane.

Recent studies have shown that virus retention by specific virus filters can be reduced at low flow rates and after process disruptions; however, the magnitude of these changes in virus retention and the underlying mechanisms controlling this behavior are still not well understood. The objective of this study was to develop a quantitative understanding of the factors controlling the virus retention behavior of a relatively homogeneous polyvinylidene fluoride virus removal filter. Data were obtained with the bacteriophage ϕX174 as a model virus.

A simple, rapid, and robust "on-the-go" identity testing of biotherapeutics using FTIR spectroscopy.

The stunning rise of biotherapeutics as successful treatments of complex and hard-to-treat diseases, in particular cancer, has necessitated the development of a rapid analytical method capable of differentiating these otherwise significantly similar antibody-based products. The existing methods for product identification pose significant drawbacks in terms of the consumption of time and labor. Here, we present an FTIR spectroscopy-based simple, rapid, and robust method that is capable of differentiating between the biotherapeutics (both innovator products and biosimilars).

Bactericidal effect of silver-reinforced carbon nanotube and hydroxyapatite composites.

Bacterial infection remains an important risk factor after orthopedic surgery. The present paper reports the synthesis of hydroxyapatite-silver (HA-Ag) and carbon nanotube-silver (CNT-Ag) composites via spark plasma sintering (SPS) route. The retention of the initial phases after SPS was confirmed by phase analysis using X-ray diffraction and Raman spectroscopy.