An emerging application of viruses involves engineering them to treat diseases using a number of approaches. Broadly defined under the “virotherapy” umbrella, these include viral vectors used for gene therapy, oncolytic viruses, and viral immunotherapy. Although a majority of these products are in various stages of clinical development, the diversity of the therapeutic targets and wealth of future opportunities is encouraging. A significant challenge, as it is for any virus-based technology, is gaining a clear picture of the quality of a sample at any given point—from early research and development through manufacturing and product release. Of prime concern is the quantification of viruses, which in the past, has relied on slow, labor-intensive, subjective methods such as plaque titer assays and electron microscopic imaging. However, the diversity of new viral technologies now being used as the basis for innovative drugs and vaccines requires advanced, sophisticated analytical systems. In this white paper, we discuss how the real-time enumeration of viruses made possible by the ViroCyt® Virus Counter® 3100 can significantly enhance the pace of virotherapy product development…
BioProcessing Journal Posts
The purification of PHB-01 plantibody derived from tobacco leaves imposed difficulties when the plantibody solid-liquid extraction design was performed. Thus, our study focused on assessing a combination of an aqueous two-phase extraction (ATPE) procedure and affinity chromatography for solving some of the issues in plantibody purification. This was done using a complete factorial redesign, different polyethylene glycol (PEG)/K2PO4 proportions, and pH values in each partitioning variant.
Sea lice are the most problematic marine pathogens the salmon industry has to deal with, significantly affecting Europe and America. The worst offenders are genera: Pseudocaligus, Caligus, and Lepeophtheirus. Over €305 million in losses are estimated. Recent results have suggested that subolesin/akirin/myosin32 are good candidate antigens for the control of arthropod infestations such as sea lice. The aim of this study was to design and optimize the purification step of MY32/Ls protein to obtain the active pharmaceutical ingredient against sea lice. Non-chromatographic purification strategies were employed, based on published works, to establish rupture, washing, solubilization, and refolding conditions…
Stem cell-based regenerative medicine has great potential to advance the therapeutic treatment of human diseases. Among the various stem cell platforms, mesenchymal stem cells (MSCs) represent one of the most promising options. Currently, there are over 500 clinical trials based on MSCs registered at the NIH’s ClinicalTrials.gov website. Although successful expansion of MSCs in vitro has been well-established, higher-yield, billion-cell expansion of MSCs remains a bottleneck. In this study, we successfully demonstrated large-scale culture of human adipose-derived mesenchymal stem cells (AdMSCs) in an industrial, single-use vessel at 3.75 L scale.
Extracellular vesicles (EVs) are particles of varying size, structure, and composition, which are secreted from cells and frequently mediate intercellular communication. Because they have been shown to travel through the circulatory system and also through biological barriers to deliver their molecular contents to distant target cells, there has been growing interest in using EVs, such as exosomes, as drug delivery vehicles. In the past ten years, the number of published articles linking EVs to drug delivery has increased 20-fold. EVs are being engineered to deliver protein, RNA, and small molecule cargo to target cells, tissues, and entire systems. Also, EVs derived from certain cells show inherent, therapeutically beneficial activity.
Agarose-based chromatography beads were first introduced by Stellan Hjertén in 1962. Fifty years later, beaded agarose has become the dominant resin for protein purification and is extensively used, ranging from research-scale in sub mL volumes to full-scale manufacturing in > 500 L chromatography columns. Recent resin development work has focused on increasing capacity and selectivity through different grafting technologies and ligand developments.
Human granulocyte colony-stimulating factor (GCSF) is produced by biotech laboratories and production facilities for reducing neutropenia duration and sequels in patients with myelosuppressor treatments, among other applications. However, real challenges for these laboratories started in 2015 when the PEGylated-GCSF patent expired, opening alternatives for developing biomanufacturing processes and new applications. Thus, the purpose of this study was to analyze downstream process controls designed to ensure recombinant human GCSF (rh-GCSF) quality and to provide some evidence of the downstream process validation status. Study outcomes proved that the rh-GCSF expression system was stable and chromatographic profiles were reproducible among samples.
Cation exchange chromatography is typically utilized in bind-and-elute mode for monoclonal antibody purification. However, during purification process development for a novel monoclonal antibody (MAb) intended for clinical use, it was determined that bind-and-elute conditions were not sufficient for removing significant levels of antibody aggregate. Based on preliminary purification data, an alternative purification method, operation of the cation exchange process in flow-through mode, was investigated.
Raman spectroscopy offers an attractive solution for monitoring key process parameters and predictive modelling in cell culture processes using transgenic Chinese hamster ovary (CHO) cells. Frequent in-line measurements offer the potential for advanced control strategies. However, an erroneous value created by analytical signal noise is a significant issue that can affect process controls negatively. One such challenge is to differentiate the signal reflecting process changes, ranging from random to gross error, in a timely manner so the process control system can respond to these changes and maintain adequate control.