Biomedical Engineering and Bioengineering Commons^™

Blood Transfusions In Preterm Infants: Changes On Perfusion Index And Intermittent Hypoxemia, Katrina T. Ibonia, Henrietta S. Bada, Philip M. Westgate, Enrique Gomez Pomar, Prasad Bhandary, Abhijit R. Patwardhan, Elie G. Abu Jawdeh

Pediatrics Faculty Publications

BACKGROUND

Red blood cell (RBC) transfusion decreases intermittent hypoxemia (IH) events beyond the first week of life. This benefit may be related to improved perfusion to the respiratory control network. Perfusion index (PI) is a perfusion measure provided by the pulse oximeter. We hypothesized that the benefit in IH after RBC transfusion is associated with an increase in PI. In addition, we assessed the value of PI and clinical measures in predicting the effect of RBC transfusion on IH.

STUDY DESIGN AND METHODS

We prospectively enrolled infants less than 30 weeks' gestation age. PI and oxygen saturation (SpO₂) …

Toward Development Of Continuous Bioprocesses: Comparison Of Fed-Batch And Perfusion Upstream Production Processes In Early Development, Jean Mclarty, Daryl Powers, Christine Hamel, Betsy Simons, Ken Karey

Cell Culture Engineering XV

Continuous Processing is an exciting development in the field of bioprocessing. The potential for quick response to market demands, decrease in infrastructure, increased flexibility and consistent product quality has resulted in a growing interest in Continuous Processing for production of all types of protein drugs (high or low volume, stable or unstable). Sanofi is developing a novel Integrated Continuous Manufacturing platform for biologics that utilizes an upstream perfusion process. While cell culture perfusion processes offer substantial benefits for commercial biologics production, implementation may present challenges in early development, where speed to first in man studies is critical. Here we present …

Non-Invasive Real-Time Monitoring Of Glucose And Lactate By Nir-Spectroscopy During Perfusion Cho Culture, Jean Hamel, Anita Wamakima, Ruifan Pei

Cell Culture Engineering XV

Near-infrared spectroscopy (NIR) has been used to monitor glycerol and methanol, non-invasively during cultures of Pichia pastoris^{1, 2}. In this work, glucose and lactate were measured in Chinese Hamster Ovary (CHO) perfusion culture, in real time, using an online advanced NIR monitor and a reference offline biochemical analyzer. The 1.8-L culture started in the batch phase at 4 g/L glucose with 0.3 x 10⁶ cells/mL and reached 1.5 x 10⁶ cells/mL after 90 hours. Perfusion was then initiated and conducted for 10 days at 0.7 vvd, using a spiral membrane-less microfluidic device³. The maximum …

Process Optimization For Semi-Continuous Virus Production At High Cell Densities, Daniel Vazquez

Cell Culture Engineering XV

Background. Unlike production of recombinant proteins, continuous production of viral vaccines at high cell densities (HCD) is still constrained by host cell lysis during virus propagation and limited virus recovery from culture broth. Nevertheless, advanced fed-batch [1] and perfusion strategies can be applied to achieve a high-yield virus production processes. In this study, the development of a high-yield semi-continuous process for the production and purification of the modified vaccinia Ankara virus isolate MVA-CR19 and influenza A/PR/8 in HCD cultivations of the suspension cell line AGE1.CR.pIX (ProBioGen AG, Berlin) is presented.

Methods. Depending on the required scale, high cell …

Size Matters: Assessment Of A Larger Pore Hollow Fiber To Reduce Product Retention In Perfusion, Samantha Wang

Cell Culture Engineering XV

Traditionally, perfusion processes using either TFF or ATF technologies have utilized hollow fibers made from polymers such as polyethersulfone (PES) or polysulfone (PS) for cell retention. The pore sizes on these hollow fibers range from several hundred kD to a few µm. However, despite the relatively large size of the pores compared to that of the product, retention of product across the hollow fiber over time is a known and common problem in perfusion. Particle size analysis demonstrated accumulation of particles around 100nm in diameter, which are unable to pass through a typical 0.2µm PES membrane. As these particles are …

Bioreactor Process Improvements In A Legacy Perfusion-Based Process, Rakesh Motani, Gonzalo Milet, Gregory Walsh, Lada Laenen

Cell Culture Engineering XV

The legacy manufacturing processes for production of the enzyme products at Genzyme include long-term bioreactor perfusion-based cell culture platform. For the process with tight filed ranges and limited characterization, a phased approach is being used to improve bioreactor productivity. In the first phase, short-term process changes that are within filed and historical ranges were implemented. In the second phase, long-term process improvements that are outside the filed ranges will be implemented for a significant improvement in bioreactor productivity. Results from lab and at-scale study have confirmed that there was no adverse impact of phase 2 process improvements on cell culture, …

Implementation Of A Recirculating Tff N-1 Perfusion System At Manufacturing Scale: Conquering Process Hurdles And Scaling Challenges, Alex Doane, Weiwei Hu, William Yang, Kelly Wiltberger, Haofan Peng

Cell Culture Engineering XV

In order to increase the output of a traditional large scale stainless steel fed-batch manufacturing facility without major engineering work, we investigated the implementation of N-1 perfusion technology to feed a more intensified fed-batch production process. Perfusion N-1 enables cells to grow to high densities in the seed train bioreactor. By shifting cell growth from production to seed train, we can increase seed train occupancy per batch and reduce production bioreactor occupancy per batch, which improves facility throughput by bringing the run duration ratio of N-1/N closer to unity. Instead of using the popular ATF technology, an in-house TFF system …

Efforts To Reduce Impact Of Media Variability On Product Quality For A Commercial Perfusion Process, Nirel Rillera, Kevin Yeh, Benjamin Youn, Jerome Acuna, John Henstrand, Sean Forestell

Cell Culture Engineering XV

Strict control of raw materials used in bioprocesses is necessary to ensure consistent product quality. However, use of poorly characterized complex components makes achieving such strict control difficult. A strong correlation between product quality variability among bulk drug substance lots and changes in a complex medium component was observed in a commercial perfusion process. This correlation was subsequently confirmed experimentally at both large and small scales. A multifaceted strategy was applied to investigate and mitigate the impact of the media variability on product quality, which included (1) studies in small scale perfusion bioreactors; (2) development of a simple cell based …

Cell-Controlled High-Intensity Perfusion And Hybrid Fed-Batch Systems That Drastically Reduce Perfusion Rates And Harmonize With Continuous Downstream Processing, Gregory Hiller, Matthew Gagnon, Ana Maria Ovalle, Bhanu Chandra, Wenge Wang, Elizabeth Eydelman

Cell Culture Engineering XV

Peak cell densities in fed-batch cultures of mammalian cells can be limited by the depletion of nutrients or accumulation of inhibitors. Since addition of nutrients is relatively straight forward, inevitably it is growth inhibitor buildup, combined with the practical limits of feed volume addition and the problem of amino acid counter ion and miscellaneous osmolyte accumulation, that serve to limit productivity in the industry standard fed-batch bioreactor. To break these barriers we have begun to investigate mixed modes of bioreactor operation, some using novel methods for cell-controlled perfusion, which can substantially reduce the volumes of perfusion medium required, suppress lactic …

Evolution Of An Integrated Continuous Antibody Manufacturing Process, Christopher Kistler

Cell Culture Engineering XV

Efforts continue to reduce the timeline and cost of progressing biologics from discovery through preclinical development to product launch. Integrated processes, those that link upstream and downstream processing with control of product quality are an attractive way to achieve meaningful reductions in the overall cost of ownership of a biologics manufacturing process.

To start along this path, an integrated continuous processing laboratory, the PROLab (Protein Refinery Operations Lab) was built to pilot the concepts of an integrated continuous antibody manufacturing process under automated control. A perfusion process was developed capable of operating for >30 days using either TFF (Spectrum KrosFlo® …

Process Optimization For Semi-Continuous Virus Production At High Cell Densities, Daniel Vazquez, Michael Pieler, Yvonne Genzel, Ingo Jordan, Volker Sandig, Udo Reichl

Cell Culture Engineering XV

Background. Unlike production of recombinant proteins, continuous production of viral vaccines at high cell densities (HCD) is still constrained by host cell lysis during virus propagation and limited virus recovery from culture broth. Nevertheless, advanced fed-batch [1] and perfusion strategies can be applied to achieve a high-yield virus production processes. In this study, the development of a high-yield semi-continuous process for the production and purification of the modified vaccinia Ankara virus isolate MVA-CR19 and influenza A/PR/8 in HCD cultivations of the suspension cell line AGE1.CR.pIX (ProBioGen AG, Berlin) is presented.

Methods. Depending on the required scale, high cell …

Overcoming Process Intensification Challenges To Deliver A Manufacturable And Competitive Integrated Continuous Biomanufacturing Platform, Jason Walther, Neha Shah, Myles Hollenbach, Jonathan Wang, Marcella Yu, Jiuyi Lu, Yang Yang, Konstantin Konstantinov, Chris Hwang

Cell Culture Engineering XV

Groups in both industry and academia have achieved high densities and productivities in perfusion cell culture processes. At Sanofi, we have demonstrated perfusion densities greater than 100 million cells/mL (with associated high productivities) at a cell-specific perfusion rate of only 20 pL/cell/day. This process intensification reduces the footprint of upstream unit operations as well as capital and operating expenses of manufacturing facilities. The continuous nature of perfusion cell culture also creates opportunities for integration of continuous downstream operations, leading to further process intensifications and volume reductions.

In this presentation, we will discuss our work on several upstream challenges that must …

Protein Refinery Operations Lab (Pro Lab): A Sandbox For Continuous Protein Production & Advanced Process Control, Mark Brower, David Pollard, Finn Hung

Integrated Continuous Biomanufacturing II

Significant strides towards implementation of continuous bioprocessing are being made at an ever increasing rate. Advances in technology for traditional unit operations such as cell-retention devices in perfusion cell culture, continuous multi-column chromatography (CMCC) and single-pass tangential flow filtration have led to demonstrations of both semi-continuous and fully-continuous protein production processes operating at periodic steady states at the pilot-scale. Previous proof of concept work at Merck & Co., Inc. has shown an automated (DeltaV) and single-use monoclonal antibody (mAb) purification scheme through Protein A CMCC and pH viral inactivation with minimal human interaction for 30 days fed from a perfusion …

Small-Scale Platform For Rapid On-Demand Manufacturing Of Recombinant Proteins, J. Christopher Love

Integrated Continuous Biomanufacturing II

The current timeline for manufacturing high-quality recombinant proteins used for therapeutics and vaccines, and delivering them to patients, typically requires many months. There are many circumstances, however, where the rapid production, release, and delivery of these biologics could address unmet medical needs, including shortages, emergency situations, and pandemics. This talk will present a new platform developed to produce biologic medicines on demand called Integrated and Scalable Cyto-Technology (InSCyT). This platform comprises an integrated, subliter-scale portable system for the (semi)continuous operation of fermentation, filtration of cell debris from secreted product, innovative affinity-based purification, polishing, and finishing. This program also emphasizes integrated …

Exploring Continuous And Integrated Strategies For The Up- And Downstream Processing Of Human Mesenchymal Stem Cells, Barbara Cunha, Tiago Aguiar, Ricardo Silva, Cristina Peixoto, Manuel Carrondo, Margarida Serra, Paula Alves

Integrated Continuous Biomanufacturing II

The integration of up- and downstream unit operations can result in the elimination of hold steps, thus decreasing the footprint, and ultimately can create robust closed system operations. This type of design is desirable for the bioprocess of human mesenchymal stem cells (hMSC), where high numbers of pure cells, at low volumes, need to be delivered for therapy applications. The aim of this work is to perform a proof of concept of the integration of a continuous perfusion culture in bioreactors with a tangential flow filtration (TFF) system for the concentration and washing of hMSC. In particular, we have evaluated …

From Fed-Batch To Perfusion: Productivity And Quality Considerations For A Late-Stage Program, Sen Xu, Hao Chen

Integrated Continuous Biomanufacturing II

In this poster, we will present the rapid development of a perfusion process with high productivity for late-stage manufacturing. The process uses a Chinese Hamster Ovary (CHO) cell line for monoclonal antibody production. Prior to the development, the clinical supply was manufactured by a fed-batch process with the same cell line.

To achieve desired productivity and comparable quality attributes, we developed a repeated batch shake flask model to rapidly screen media and process conditions. Shake flasks were inoculated at 10 × 10⁶ cells/mL and maintained in a CO₂ incubator with medium exchange for every 48 hours, repeated for …

Designing A Microbial Cultivation Platform For Continuous Biopharmaceutical Production, Nicholas Mozdzierz, Kerry Love, Alan Stockdale, John Clark, Noelle Colant, Christopher Love

Integrated Continuous Biomanufacturing II

The existing biopharmaceutical manufacturing paradigm is poorly suited to produce biologic drugs on demand at a point-of-care. Generally, commercial-scale (~2,000 - 10,000 L) manufacturing using fed-batch cultivation and fixed stainless-steel infrastructure is concentrated in developed nations and results in process cycle times on the order of weeks to months.^1,2 Coupled with the complex logistical challenges associated with continuous “plant-to-patient” cold-chains, the geographically biased nature of therapeutic protein production today can limit access to biologic drugs in developing areas of the world.³ There is an opportunity to create technologies capable of rapidly generating biopharmaceuticals in situ in emergency situations, …

Integrated Solutions For Continuous Processing In Mobius® Bioreactor Systems, Andrew Clutterbuck

Integrated Continuous Biomanufacturing II

Throughout the bioprocess industry, the use of disposable systems such as bioreactors is playing an increasingly significant role. Manufactures are recognising the strategic benefits of single use systems in both reducing production costs and increasing overall manufacturing throughput.

Over the past few years there has been increasing demand for larger scale disposable bioreactor systems, to satisfy the manufacturing demands and an emphasis on suppliers such as Merck Millipore to demonstrate robust and reproducible scale-up within these systems.

This presentation will explore the design philosophies behind the Mobius^® bioreactors and will also give an overview of the novel SensorReady external …

Pilot Scale Hybrid Fed Batch And Continuous Processing Of Biologics, Dave Sullivan, Michael O'Connor, Samir Gondalia, Matt Gagnon

Integrated Continuous Biomanufacturing II

Pfizer Bioprocessing R&D is focused on developing enabling technologies that will reduce capital and operational expenses, decrease equipment scale, increase automation and utilize fewer FTEs. To realize this vision, our Pilot Facility has partnered with our cell culture process development colleagues to adapt a fed batch platform 150L stainless steel bioreactor to run in hybrid perfusion, standard perfusion, low volume cell controlled perfusion, and continuous stirred tank modes. Through adjustments to impeller configuration, sparging strategy, and addition ports the bioreactor was able to deliver multiple batches that produced ~3X gains in cell density and volumetric productivity versus conventional fed batch …

Use Of Imaging Biomarkers To Assess Perfusion And Glucose Metabolism In The Skeletal Muscle Of Dystrophic Mice, Nabeel Ahmad, Ian Welch, Robert Grange, Jennifer Hadway, Savita Dhanvantari, David Hill, Ting-Yim Lee, Lisa M Hoffman

Robarts Imaging Publications

BACKGROUND: Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease that affects 1 in 3500 boys. The disease is characterized by progressive muscle degeneration that results from mutations in or loss of the cytoskeletal protein, dystrophin, from the glycoprotein membrane complex, thus increasing the susceptibility of contractile muscle to injury. To date, disease progression is typically assessed using invasive techniques such as muscle biopsies, and while there are recent reports of the use of magnetic resonance, ultrasound and optical imaging technologies to address the issue of disease progression and monitoring therapeutic intervention in dystrophic mice, our study aims to validate …

Investigation Of Lower-Limb Tissue Perfusion During Loading, Barbara Silver-Thorn

Biomedical Engineering Faculty Research and Publications

An extant tissue indentor used for amputee residual limb tissue indentation studies was modified to include laser Doppler flowmetry (LDF) to enable measurement of tissue perfusion during indentation. This device allows quantitative assessment of the mechanical and physiological response of soft tissues to load, as demonstrated by indentation studies of the lower-limb tissues of young healthy subjects. Potential measures of interest include the relative change in tissue perfusion with load and the time delays associated with the perfusion response during tissue loading and unloading. Such measures may prove useful in future studies of residual limb tissues, improving our understanding of …

Effective Estimation And Computer Control Of Minimum Tumour Temperature During Conductive Interstitial Hyperthermia, J A. Deford, Charles F. Babbs, U H. Patel, M W. Bleyer, J A. Marchosky, C J. Moran

Weldon School of Biomedical Engineering Faculty Publications

The goal of heat therapy in the treatment of malignant disease is to raise the temperature of all neoplastic tissue to a cytotoxic temperature for a predetermined period of time. This seemingly simple task has proved difficult in-vivo, in part because of nonuniform power absorption and in part because of nonhomogeneous and time varying tumour blood flow. We have addressed this difficulty first by utilizing the conceptually simple technique of conductive interstitial hyperthermia, in which the tumour is warmed by multiple, electrically heated catheters, and second by implementing on-line conu·ol of minimum tumour temperatures near each catheter, estimated on the …

Regional Blood Flow During Cardiopulmonary Resuscitation With Abdominal Counterpulsation In Dogs, William D. Voorhees Iii, Sandra H. Ralston, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The addition of abdominal counterpulsation to standard cardiopulmonary resuscitation (IAC-CPR) during ventricular fibrillation has been shown to improve cardiac output, oxygen uptake, and central arterial blood pressure in dogs. The present study was performed to determine the effect of IAC-CPR on regional blood flow. Regional blood flow was measured with radioactively labeled microspheres during sinus rhythm and during alternate periods of IAC-CPR and standard CPR (STD-CPR) in nine dogs anesthetized with pentobarbital. Blood pressures and oxygen uptake were measured continuously. As in previous studies, diastolic arterial pressure was higher (30.8%) during IAC-CPR than during STD-CPR, as were cardiac output (24.5%) …