Virus Removal and Inactivation in Process Validation

An investigation was undertaken on the removal of a model virus, bacterial virus MS2 against Escherichia coli, by sand filtration using untreated, and alum or cationic polyelectrolyte treated media, and uncoagulated as well as alum coagulated influent. Data on discrete virus removal were satisfactorily accounted for by electrokinetic phenomena and diffusion. For virus in association with turbidity, filter coefficients computed from experimental data were in good agreement with those predicted by mechanical straining and gravity settling which were the dominant mechanisms for removal of the turbidity particles to which the viruses attached.

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A New Technique for the Enumeration of Rotaviruses in Wastewater Samples

Water Science & Technology ◽

10.2166/wst.1989.0085 ◽

1989 ◽

Vol 21 (3) ◽

pp. 99-104 ◽

Cited By ~ 2

Author(s):

J. I. Oragui ◽

D. D. Mara ◽

S. A. Silva ◽

A. M. Konig

Keyword(s):

Inorganic Ions ◽

Assay Method ◽

Toxic Substances ◽

Waste Stabilization Ponds ◽

Virus Removal ◽

Molecular Weights ◽

Large Numbers ◽

Waste Stabilization ◽

A New Technique ◽

Wastewater Samples

Rotaviruses are generally excreted in large numbers in diarrhoeal stools, but in wastewaters their numbers are subject to variations. Detection and enumeration of these viruses involve a concentration step followed by an assay method. Enumeration in wastewater concentrates is complicated by the presence of toxic substances which are often concentrated with the viruses. These toxic substances often cause the destruction of cells during rotavirus assay, thus leading to underestimation of viral numbers. Such concentrates were detoxified by a simple and effective method using polyacrylamide (Biogel P-6DG) or dextran (Sephadex G50) beads. Concentrates (10 ml) were mixed with 0.5 g gel and the mixtures were allowed to stand for 2 h at room temperature during which time the beads swell by the passage of water into them along with inorganic ions and substances with molecular weights of less than 30,000. The supernatants were then decontaminated with antibiotics and assayed for rotaviruses by the indirect immunofluorescent technique. Most untreated ultrafiltrates of raw sewage and those from anaerobic ponds were found to be too toxic to MA104 and LLC MK2 cells, whereas the above treatment rendered over 90% of wastewater concentrates non-toxic to cells. This technique was used to study virus removal in samples from deep waste stabilization ponds in northeast Brazil.

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Injectable Hydrogels: From Laboratory to Industrialization

Polymers ◽

10.3390/polym13040650 ◽

2021 ◽

Vol 13 (4) ◽

pp. 650

Author(s):

Jose Maria Alonso ◽

Jon Andrade del Olmo ◽

Raul Perez Gonzalez ◽

Virginia Saez-Martinez

Keyword(s):

Industrial Process ◽

Functional Materials ◽

Point Of View ◽

Industrial Scale ◽

Injectable Hydrogels ◽

Safety And Efficacy ◽

Process Validation ◽

Characterization Techniques ◽

Hyaluronic Acid Hydrogel ◽

Lack Of Knowledge

The transfer of some innovative technologies from the laboratory to industrial scale is many times not taken into account in the design and development of some functional materials such as hydrogels to be applied in the biomedical field. There is a lack of knowledge in the scientific field where many aspects of scaling to an industrial process are ignored, and products cannot reach the market. Injectable hydrogels are a good example that we have used in our research to show the different steps needed to follow to get a product in the market based on them. From synthesis and process validation to characterization techniques used and assays performed to ensure the safety and efficacy of the product, following regulation, several well-defined protocols must be adopted. Therefore, this paper summarized all these aspects due to the lack of knowledge that exists about the industrialization of injectable products with the great importance that it entails, and it is intended to serve as a guide on this area to non-initiated scientists. More concretely, in this work, the characteristics and requirements for the development of injectable hydrogels from the laboratory to industrial scale is presented in terms of (i) synthesis techniques employed to obtain injectable hydrogels with tunable desired properties, (ii) the most common characterization techniques to characterize hydrogels, and (iii) the necessary safety and efficacy assays and protocols to industrialize and commercialize injectable hydrogels from the regulatory point of view. Finally, this review also mentioned and explained a real example of the development of a natural hyaluronic acid hydrogel that reached the market as an injectable product.

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Getting a handle on the fault injection process: validation of measurement tools

Proceedings Fifth International Software Metrics Symposium. Metrics (Cat. No.98TB100262) ◽

10.1109/metric.1998.731238 ◽

2002 ◽

Cited By ~ 2

Author(s):

S.G. Elbaum ◽

J.C. Munson

Keyword(s):

Fault Injection ◽

Process Validation ◽

Injection Process ◽

Measurement Tools

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Direct visualization of virus removal process in hollow fiber membrane using an optical microscope

Scientific Reports ◽

10.1038/s41598-020-78637-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Miku Ayano ◽

Yoshiyuki Sawamura ◽

Tomoko Hongo-Hirasaki ◽

Takayuki Nishizaka

Keyword(s):

Hollow Fiber ◽

Hollow Fiber Membrane ◽

Imaging Techniques ◽

Basic Research ◽

Optical Microscope ◽

Regenerated Cellulose ◽

Fiber Membrane ◽

Virus Removal ◽

Novel Method ◽

Pass Through

AbstractVirus removal filters developed for the decontamination of small viruses from biotherapeutic products are widely used in basic research and critical step for drug production due to their long-established quality and robust performance. A variety of imaging techniques have been employed to elucidate the mechanism(s) by which viruses are effectively captured by filter membranes, but they are limited to ‘static’ imaging. Here, we propose a novel method for detailed monitoring of ‘dynamic process’ of virus capture; specifically, direct examination of biomolecules during filtration under an ultra-stable optical microscope. Samples were fluorescently labeled and infused into a single hollow fiber membrane comprising cuprammonium regenerated-cellulose (Planova 20N). While proteins were able to pass through the membrane, virus-like particles (VLP) accumulated stably in a defined region of the membrane. After injecting the small amount of sample into the fiber membrane, the real-time process of trapping VLP in the membrane was quantified beyond the diffraction limit. The method presented here serves as a preliminary basis for determining optimum filtration conditions, and provides new insights into the structure of novel fiber membranes.

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Aggregate Removal Nanofiltration of Human Serum Albumin Solution Using Nanocellulose-Based Filter Paper

Biomedicines ◽

10.3390/biomedicines8070209 ◽

2020 ◽

Vol 8 (7) ◽

pp. 209 ◽

Cited By ~ 1

Author(s):

Lulu Wu ◽

Athanasios Mantas ◽

Simon Gustafsson ◽

Levon Manukyan ◽

Albert Mihranyan

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Filter Paper ◽

High Performance ◽

Size Exclusion ◽

Transmembrane Pressure ◽

Protein Loss ◽

Virus Removal ◽

Model Virus

This study is dedicated to the rapid removal of protein aggregates and viruses from plasma-derived human serum albumin (HSA) product to reduce the risk of viral contamination and increase biosafety. A two-step filtration approach was implemented to first remove HSA aggregates and then achieve high model virus clearance using a nanocellulose-based filter paper of different thicknesses, i.e., 11 μm (prefilter) and 22 μm (virus filter) at pH 7.4 and room temperature. The pore size distribution of these filters was characterized by nitrogen gas sorption analysis. Dynamic light scattering (DLS) and size-exclusion high performance liquid chromatography (SE-HPLC) were performed to analyze the presence of HSA aggregates in process intermediates. The virus filter showed high clearance of a small-size model virus, i.e., log10 reduction value (LRV) > 5, when operated at 3 and 5 bar, but a distinct decrease in LRV was detected at 1 bar, i.e., LRV 2.65–3.75. The throughput of HSA was also dependent on applied transmembrane pressure as was seen by Vmax values of 110 ± 2.5 L m−2 and 63.6 ± 5.8 L m−2 at 3 bar and 5 bar, respectively. Protein loss was low, i.e., recovery > 90%. A distribution of pore sizes between 40 nm and 60 nm, which was present in the prefilter and absent in the virus filter, played a crucial part in removing the HSA aggregates and minimizing the risk of virus filter fouling. The presented results enable the application of virus removal nanofiltration of HSA in bioprocessing as an alternative to virus inactivation methods based, e.g., on heat treatment.

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