Mammalian cell culture processes require an in depth understanding of inputs and outputs in order to maximize productivity, efficiency, and product quality. Daily monitoring of essential metabolites, nutrients, and protein titer using at-line analyzers are the building blocks of drug manufacturing process development and characterization. In order to better understand how these instruments perform, a comparative analysis was conducted using two different classes of metabolicsensing technologies, membrane-based technology (MBT) and absorption photometric-based technology (APBT). Four commercially available instruments were examined using various samples and maintenance conditions in order to emphasize the following testing criteria: specificity, linearity, range, accuracy, and precision. Samples included standard solutions with known metabolite concentrations, cell culture supernatant, and supernatant liquid spiked with additional metabolite solutions. The results from our testing indicated that the photometric analyzers yielded more accurate and consistent results than the membrane-based analyzers and were easier and less time-consuming to maintain. Ultimately, these studies summarized the capabilities and limitations for both types of analyzers and provide a critical summary for instruments used in everyday bioprocess monitoring…
Category: <span>Analytics</span>
Immunoaffinity chromatography is an indispensable purification tool. However, its use has been limited by cost, purification cycle numbers, and storage requirements. Therefore, authors speculated that a possible solution to these problems could be CB.Hep-1 monoclonal antibody (mAb)-immunosorbent lyophilization. This study sought to assess the impact of the CB.Hep-1 mAb quantification by enzyme-linked immunoadsorbent assay and the CB.Hep-1 mAb-immunosorbent lyophilization process for its impact on hepatitis B virus surface antigen purification for pharmaceutical use. Study results found that CB.Hep-1 mAb lyophilization did not affect mAb purity and antigen recognition capacity. CB.Hep-1 mAb-immunosorbent lyophilization did not modify volume-weight factor, infrared spectrum, particle-size distribution, particle density and viscosity, antigen adsorption capacity, antigen elution capacity, antigen recovery, antigen purity, gamma immunoglobulin (IgG) leakage, and purification cycle number. Therefore, the lyophilized CB.Hep-1 mAb and CB.Hep-1 mAb-immunosorbents can be successfully used for hepatitis B vaccine production…
Mammalian cell line generation is foundational to protein-based therapeutic product development. Ensuring production cell line “clonality” (i.e., clonal derivation of the production cell line) is a requirement for product registration. Many single-cell deposition approaches have been developed since the inception of traditional limiting-dilution. However, regulatory expectations, in line with the capability of this original cloning technique, still lead many institutions to either execute multiple rounds of single-cell plating or conduct extensive screening immediately post-cloning to demonstrate the single-cell origin of a production cell line. Using fluorescence-activated cell sorting (FACS), we have developed a strategy to verify single-cell deposition that, when combined with statistical analysis, creates a highly-effective and efficient process for generating clonally-derived production cell lines in just one round of plating…
The evaluation of bacteriocin cytotoxicity is a critical first step in guaranteeing its safe use in food and therapeutic applications. In this study, the bacteriocins nisin, pediocin, and colicin ([Col] E1, E3, E6, E7, and K) were evaluated for cytotoxicity against cultured mammalian cells. Cellular membrane potential (delta psi) changes of bacteriocin-treated cells were used as an index of cytotoxicity. Simian virus 40-transfected human colon (SV40-HC) cells and African green monkey kidney epithelial cells (Vero) cells were cultured (35°C, 10% CO2, humidified air) as monolayers on tissue culture plates. Log phase cells (~104 cells/mL) were treated with partially purified, individual bacteriocin preparations at 170, 350, and 700 activity units (AU)/mL…
Cell therapy products derived from adipose tissue have some unique processing issues with regard to obtaining accurate cell counts. This is because processing methods may not only show us the nucleated stromal vascular fraction (SVF) cells but also the micellular and microvesicle particles. This is true for both veterinary and human clinical products, and poses special concerns for in-clinic processing where the cell therapy dose is correlated with cell numbers and other QC data is not especially useful. In this study, multiple cell counting methods were compared for SVF cell preparation that were derived from canine adipose tissue using commercially-available processing kits. The data clearly showed that many non-nucleated particles appear cell-like by size and shape, and can lead to counting errors with automated counters. In addition, certain reagents important to processing can have properties wherein the reagents alone (e.g., lecithin) may be counted as cells. The most accurate cell numbers were from hemocytometer-counting of cells stained with 4´,6-diamidino-2-phenylindole (DAPI) which shows the nuclei in concert with a viability stain such as trypan blue. The data clearly showed that care must be taken when counting cells used as a therapeutic dose…
Efficient bioprocess characterization is essential for both regulatory compliance and commercial viability of biologics. Traditional approaches using resolution III/IV screening designs followed by response surface methodology are time-consuming, costly, and not always effective in identifying the important experimental effects. Definitive screening designs (DSDs) represent a novel class of three-level screening designs that can simultaneously evaluate main effects and quadratic relationships. While DSDs are increasingly used in bioprocess development, practical implementation guidelines remain limited. This case study bridges this gap by introducing a model-based framework to identify critical process parameters (CPPs) and optimize operating ranges for robust biologics production using plasmid DNA (pDNA). Minimal 14-run DSDs evaluated six input parameters and successfully identified CPPs and optimal operating ranges. This approach reduces experimental requirement by >50% compared to traditional designs, providing an efficient and economical strategy for bioprocess characterization and optimization.
This study assessed a novel statistical approach using space-filling designs (SFDs) and self-validating ensemble modeling (SVEM) machine learning to efficiently identify key process factors using recombinant adeno-associated virus type 9 (rAAV9) gene therapy manufacturing as a case study. Based on risk assessment of parameters that may impact rAAV9 production, we have evaluated six process parameters using 24-run SFDs generated by the JMP statistical software. SFDs are a new class of design of experiment (DoE) created with the objective of covering the entire design space as completely as possible; this in turn allows more accurate modeling of complex response surface behavior typically found in bioprocesses.
The price per patient for protein-based and monoclonal antibody (mAb) therapies runs into thousands of dollars per patient each year. These therapies cost considerably more to manufacture than small molecules. Hence, if mammalian or insect cell lines expressing high protein titres can be selected and optimized for protein expression using microscale bioreactor models early in development, then manufacturing costs can be reduced significantly…