Biomedical Engineering and Bioengineering Commons^™

Methodological Considerations Of Electron Spin Resonance Spin Trapping Techniques For Measuring Reactive Oxygen Species Generated From Metal Oxide Nanomaterials, Min Sook Jeong, Kyeong-Nam Yu, Hyun Hoon Chung, Soo Jin Park, Ah Young Lee, Mi Ryoung Song, Myung-Haing Cho, Jun Sung Kim

Chemical & Biomedical Engineering Faculty Publications

Qualitative and quantitative analyses of reactive oxygen species (ROS) generated on the surfaces of nanomaterials are important for understanding their toxicity and toxic mechanisms, which are in turn beneficial for manufacturing more biocompatible nanomaterials in many industrial fields. Electron spin resonance (ESR) is a useful tool for detecting ROS formation. However, using this technique without first considering the physicochemical properties of nanomaterials and proper conditions of the spin trapping agent (such as incubation time) may lead to misinterpretation of the resulting data. In this report, we suggest methodological considerations for ESR as pertains to magnetism, sample preparation and proper incubation …

Can Neuromorphic Computer Vision Inform Vision Science? Disparity Estimation As A Case Study, Guido Maiello, Manuela Chessa, Peter J. Bex, Fabio Solari

MODVIS Workshop

The primate visual system efficiently and effectively solves a multitude of tasks from orientation detection to motion detection. The Computer Vision community is therefore beginning to implement algorithms that mimic the processing hierarchies present in the primate visual system in the hope of achieving flexible and robust artificial vision systems. Here, we reappropriate the neuroscience “borrowed” by the Computer Vision community and ask whether neuromorphic computer vision solutions may give us insight into the functioning of the primate visual system. Specifically, we implement a neuromorphic algorithm for disparity estimation and compare its performance against that of human observers. The algorithm …

Fed-Batch Process Development Using Metabolically Efficient Cho Cells, Cecile Toussaint

Cell Culture Engineering XV

The development and application of fed-batch strategies have greatly contributed to the improvement of the productivity of cell culture processes. However, in such processes, lactate and ammonia accumulation in the culture medium over time can have detrimental impacts on cell growth and product quality. Continuous cell lines typically exhibit an inefficient metabolism whereby most of the pyruvate derived from glucose is diverted to lactate and only a small percentage is incorporated into the TCA cycle. Thus, further process improvements can be expected by combining the application of rational fed-batch strategies with targeted metabolic engineering of cells to reduce waste metabolite …

Deepening Knowledge On Cho Cells Metabolism Using Multiple Tracer Substrates, Ana Teixeira, Manuel Carrondo

Cell Culture Engineering XV

Optimization of culture conditions through trial-and-error has led to much of the past progress on animal cell culture. Today, a renewed account of the underlying biologies through a “systems” view is providing a deeper knowledge of cellular physiology and laying the basis to reengineer desirable states of further increased culture performance. In this work, we took a comprehensive view of cellular metabolism by extensively profiling extracellular and intracellular metabolomes after ¹³C‑label supplementation in parallel labelling cultures of [1,2-¹³C]Glucose, [U-¹³C,¹⁵N]Asn, [U-¹³C,¹⁵N]Ser and [1-¹³C]Pyruvate. This integrative approach was used …

A Holistic Approach To Facility Protection From Adventitious Agents – A Case Study, Matthew Osborne, Ronan Kelly, Ann Maria Mccrohan, Marie Murphy

Cell Culture Engineering XV

The Eli Lilly biologics manufacturing facility in Kinsale, Ireland has been operational since 2010 with a 100% cell culture contamination control success rate. The presentation will review the holistic approach to facility protection from adventitious agents that underpins this success including:

• The risk assessment approach to points of entry and management via detectability and control measures
• The approach to personnel training that considers human factors, increased vigilance and event simulations following strategies that are used in chemical synthesis process safety

The presentation will then focus on control of adventitious virus. The talk will briefly comment on the early warning measures …

Building Qbd Frameworks Retrospectively For Commercial Products And The Use Of Scale-Down Model Qualification Strategies To Support Continuous Improvement, Jose Menezes, Francisca Gouveia, Pedro Felizardo

Cell Culture Engineering XV

A science-based justification for many continuous improvement and post-approval submissions on ‘legacy products’ (i.e., commercial products developed without a QbD rationale) requires that some of those missing QbD elements in the original filing, be defined retrospectively.

Here we present a new proposal to achieve that, that is general and very capable of supporting the transition of ‘legacy’ non-QbD into quasi-QbD filings. It is based on (1) a formal criticality analysis to the current process version to support the choice of quality attributes and process parameters in the filing, and identification of additional ones that may impact the quality target-product profile …

Separation Of Igg Glycoforms For Biosimilars Development Using Fc Gamma Receptors As Affinity-Based Chromatography Ligands, Austin Boesch

Cell Culture Engineering XV

Abstract: In biosimilars development, matching the glycosylation pattern of the innovator molecule can be a significant challenge in cell culture development. Here we present a novel downstream method using Fc gamma receptors as chromatography affinity ligands to separate monoclonal antibody glycoforms. Additional data is presented highlighting glycoform potentiation of effector functions such as antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis which can be important mechanisms of action to consider in biosimilars development

Nanofiltration As An Effective Means To Prevent Virus Contamination Of Cell Culture Processes, Christina Carbrello

Cell Culture Engineering XV

While cell culture media is typically sterile filtered to remove bacteria and mycoplasma, many bioreactors remain unprotected from viral contamination. As awareness of the risk for viral contamination of cell culture processes grows, manufacturers are seeking virus barrier technologies to remove or inactivate viruses. Filtration is an ideal technology in terms of familiarity, ease of use and scalability. However, hurdles to its implementation remain, most notably, the high cost and large footprints required to implement filters designed for the downstream process and the concern that the small pore size of virus filters could impact cell culture performance. A filter specifically …

Improvement Of Cho Specific Productivity Using Amino Acid Derivatives, Aline Zimmer, Caroline Hecklau, Sascha Pering, Alisa Schnellbaecher, Thomas Eichhorn

Cell Culture Engineering XV

Industrial fed-batch cultivation of mammalian cells is used for the production of therapeutic proteins such as monoclonal antibodies. Besides medium ensuring initial growth, feeding is necessary to improve growth, viability and antibody production. Amino acids are key elements for the cellular metabolism but also for the quality of the recombinant protein produced. Several studies have already demonstrated the link between amino acid availability and sequence variants [1-3] or specific modifications like trisulfide bonds [4]. To avoid such modifications, the chemical modification of amino acids is an interesting alternative to modulate their overall solubility [5], …

Development Of An Enriched Cho Feed Media For Quality Therapeutic Antibody Production From High Performing Clones, David Ho

Cell Culture Engineering XV

The use of feed media during protein production is essential to sustain viable cell densities and facilitate high productivity for modern high performing clones. However, the introduction of feed media can also have a significant impact on product quality attributes, such as glycosylation for therapeutic antibodies, which can ultimately impact therapeutic efficacy. For certain antibodies, the absence of fucose on the N-glycan at Asparagine 297 of the Fc domain has been shown to significantly increase binding to the FcgammaRIII receptor on NK cells and results in increased ADCC activity. Here we have incorporated product quality analysis including N-glycan analysis into …

Using Definitive Screening Design To Effectively Assess The Combinatorial Impacts Of Media Supplements On Monoclonal Antibody Production In Mammalian Cells, Aaron Chen

Cell Culture Engineering XV

Process understanding is an essential component of QbD principles. Cell culture media composition can impact many process performance parameters such as viable cell density, product yield and product quality attributes. In order to enhance process understanding and exert better process control, numerous media supplements have previously been tested. However, their combinatorial effects on process and product quality have largely been unexplored. This is partially due to the resource and efforts required to execute relatively large size of experiment and data analysis.

Recent advancement in modern design of experiment methodology has alleviated this issue. The definitive screening design (DSD) allows for …

Adapting An In-Licensed/Acquired Cell Culture Process To Platform Conditions, Raghunath Shivappa

Cell Culture Engineering XV

The use of platform materials and processes for new products help streamline process development, enhance predictability and efficiency during manufacturing, and simplify the raw materials supply chain. Although common, adaptation of cell expression systems can require a significant amount of process development work to achieve desired product yield, quality, and comparability. Here, we present a progressive development approach for evaluating platform media and feeds for an acquired cell culture process.

A CHO-DG 44 cell line expressing a novel antibody product was procured through acquisition. The original non-platform media and fed-batch process yielded titers of approximately 3 g/L. A study was …

Antibody Production With Site-Specific Non-Natural Amino Acid Incorporation For Generation Of Antibody Drug Conjugates, Alyssa Powell

Cell Culture Engineering XV

Ambrx’s mammalian expression platform (EuCODE) enables site-specific incorporation of non-natural amino acids into antibodies. This EuCODE technology provides a means for stable payload linkages at defined sites and with a defined DAR of 2 for antibody drug conjugate (ADC) generation. While the ability to control the DAR and payload site can provide an advantage to an ADC, the incorporation of the non-natural amino acid into the antibody heavy chain introduces a unique challenge for antibody production.

To achieve high production of monoclonal antibodies (mAbs) containing non-natural amino acids, we engineered a CHO-K1 cell line which stably contains Ambrx’s patented tRNA …

Development Of A Chemically Defined Media And A Chemically Defined Feeding Strategy For Extended Growth And Enhanced Productivity In Cho-K1 And Cho Dg44 Cultures, Sagar Kokal, Kyle Liu, John Menton

Cell Culture Engineering XV

The biopharmaceutical industry utilizes Chinese Hamster Ovary (CHO) cells for the production of recombinant proteins. Due to regulatory restrictions, there has been much focus on using serum-free culture processes including chemically defined (CD) media and feed system. A great deal of time and cost has been invested by biopharmaceutical companies for the development of an optimal CD media. Currently, the fed-batch process is the most dominant method for the large cultivation of CHO cells. In response to these industry requirements, Kerry has developed a complete system including a CD media called Sheff-CHO CD complete and a CD feed system named …

Evaluating Sugar-Based Detergents As A Potential Alternative To Poloxamer Bubble Protectant, Jessica Wuu, Jayanthi Lakkyreddy, Steven Meier

Cell Culture Engineering XV

Poloxamer 188 (commonly referred to as Pluronic® F-68) is a commonly-used medium component which protects against bubble-induced shear in mammalian cell cultures. Recently, concerns have arisen due to limited sourcing and variable performance of this critical component. In 2008, Hu, et al.¹ proposed the use of sugar-based detergents – specifically, maltopyranosides and glucopyranosides – as potential bubble protectants based on their rheological properties and relatively low toxicity to cells. This work explores the feasibility of these detergents using commercially relevant CHO cell lines and media. Detergent candidates were evaluated based on their tolerance by cells, stability in cell culture …

Adaptation Of Cho Metabolism To Long Term Phosphate Limitation, Mugdha Gadgil

Cell Culture Engineering XV

Phosphate is an important component of abundant intracellular molecules like RNA, is a critical component of energy metabolism and is involved in substrate phosphorylation in cellular metabolism and signaling. Inorganic phosphate (P_i) is transported through specialized transporter proteins and limitation in the availability of phosphate in the growth medium limits cell growth. P_i concentrations have been reported to regulate the rates of aerobic glycolysis and oxygen uptake. Thus it is expected that cellular metabolism will adapt to long term phosphate restriction. Since complete phosphate deprivation will result in lack of growth, such an adaptation needs to be …

Impact Of Poloxamer 188 Variability On Biologics Manufacturing: Mitigations And Causal Investigation, Salim Charaniya

Cell Culture Engineering XV

Poloxamer 188 (P188), a water-soluble, synthetic copolymer with hydrophilic as well as lipophilic properties, is widely used as a cell protectant for bubble-induced shear during cultivation of suspension-adapted mammalian cells for large-scale production of protein-based therapeutics. Poor cell growth and lower product yield has been recently observed at commercial scales in more than one Chinese hamster ovary-based manufacturing process within Roche network when specific lots of P188 were used. An investigation is being conducted to unearth the root cause of “poor-performing” P188 lots and to identify means to mitigate the product supply risks. P188 raw material is currently sourced from …

A Host Cell Protein That May Impact Polysorbate Degradataion, Kelvin Lee

Cell Culture Engineering XV

There is growing interest and concern related to host cell proteins. Current issues with host cell proteins include questions related to the various available analytical approaches and the sensitivity of those approaches as well as issues with purification strategies and the impact of host cell proteins downstream. The availability of a sequenced genome enables new opportunities to address problematic host cell proteins via cell line engineering. We studied difficult to remove host cell proteins in CHO cells with the goal of identifying host cell proteins that may be product associated with a number of monoclonal antibodies, that may copurify with …

The Differential Polarizability Of Cho Cells Can Be Used To Monitor Changes In Metabolism, Katrin Braasch

Cell Culture Engineering XV

The continuous monitoring of cell growth and viability is an integral part of biopharmaceutical production. Measurements of changes in the polarizability of individual cells can identify early emerging sub-populations of apoptotic cells in a dielectrophoretic (DEP) cytometer designed at the University of Manitoba. In this instrument the trajectory of individual cells was tracked as they passed through a bank of electrodes (sensitivity: 0.1 µm; rate: 5 cells per second) designed to differentially perturb the cells according to their polarizability. This perturbation was recorded as a force index (FI), which was related to the electrical displacement of the cells. Using this …

Development Of Antibody Detection Methods For Active Product At The Cell Culture Stage, Gregory Walsh, Matthew Schraut, Jon Barricelli, Lada Laenen

Cell Culture Engineering XV

Development of new analytical methods to characterize the manufacturing process became necessary when the site wanted to implement process improvements to increase output from the bioreactor. The bioreactor process is monitored and controlled for dissolved oxygen content, glucose concentration, temperature, etc. and samples of the harvest are analyzed daily using an endpoint assay and a total protein method. Neither of the two methods can detect the total amount of product at the harvest stage; the endpoint assay will only detect active product and the total protein method will not discriminate between the cellular proteins and the active product. We have …