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Robust Bioprocess Design and Evaluation of Commercial Media for the Serial Expansion of Human Induced Pluripotent Stem Cell Aggregate Cultures in Vertical-Wheel Bioreactors

Abstract Background: While pluripotent stem cell (PSC) therapies move toward clinical and commercial applications at a rapid rate, manufacturing reproducibility and robustness are notable bottlenecks in regulatory approval. Therapeutic applications of PSCs require large cell quantities to be generated under highly robust, well-defined, and economically viable conditions. Small-scale and short-term process optimization, however, is often performed in a linear fashion that does not account for time needed to verify the bioprocess protocols and analysis methods used. Design of a reproducible and robust bioprocess should be dynamic and include a continuous effort to understand how the process will respond over time and to different stresses before transitioning into large-scale production where stresses will be amplified. Methods: This study utilizes a baseline protocol, developed for the short-term culture of PSC aggregates in Vertical-Wheel® bioreactors, to evaluate key process attributes through long-term (serial passage) suspension culture. This was done to access overall process robustness when performed with various commercially available media and cell lines. Process output variables including growth kinetics, aggregate morphology, harvest efficiency, genomic stability, and functional pluripotency were assessed through short and long-term culture. Results: The robust nature of the expansion protocol was demonstrated over a six-day culture period where spherical aggregate formation and expansion were observed with high-fold expansions for all five commercial media tested. Profound differences in cell growth and quality were revealed only through long-term serial expansion and in-vessel dissociation operations. Some commercial media formulations tested demonstrated maintenance of cell growth rates, aggregate morphology, and high harvest recovery efficiencies through three bioreactor serial passages using multiple PSC lines. Exceptional bioprocess robustness was even demonstrated with sustained growth and quality maintenance over 10 serial bioreactor passages. However, some commercial media tested proved less equipped for serial passage cultures in bioreactors as cultures led to cell lysis during dissociation, reduction in growth rates, and a loss of aggregate morphology. Conclusions: This study demonstrates the importance of systematic selection and testing of bioprocess input variables, with multiple bioprocess output variables through serial passages to create a truly reproducible and robust protocol for clinical and commercial PSC production using scalable bioreactor systems.

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Upscaling human mesenchymal stromal cell production in a novel vertical-wheel bioreactor enhances extracellular vesicle secretion and cargo profile.

Human mesenchymal stromal cells (hMSCs) are mechanically sensitive undergoing phenotypic alterations when subjected to shear stress, cell aggregation, and substrate changes encountered in 3D dynamic bioreactor cultures. However, little is known about how bioreactor microenvironment affects the secretion and cargo profiles of hMSC-derived extracellular vesicles (EVs) including the subset, "exosomes", which contain therapeutic proteins, nucleic acids, and lipids from the parent cells. In this study, bone marrow-derived hMSCs were expanded on 3D Synthemax II microcarriers in the PBS mini 0.1L Vertical-Wheel bioreactor system under variable shear stress levels at 25, 40, and 64 RPM (0.1-0.3dyn/cm2). The bioreactor system promotes EV secretion from hMSCs by 2.5-fold and upregulates the expression of EV biogenesis markers and glycolysis genes compared to the static 2D culture. The microRNA cargo was also altered in the EVs from bioreactor culture including the upregulation of miR-10, 19a, 19b, 21, 132, and 377. EV protein cargo was characterized by proteomics analysis, showing upregulation of metabolic, autophagy and ROS-related proteins comparing with 2D cultured EVs. In addition, the scalability of the Vertical-Wheel bioreactor system was demonstrated in a 0.5L bioreactor, showing similar or better hMSC-EV secretion and cargo content compared to the 0.1L bioreactor. This study advances our understanding of bio-manufacturing of stem cell-derived EVs for applications in cell-free therapy towards treating neurological disorders such as ischemic stroke, Alzheimer's disease, and multiple sclerosis.

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Evaluation of a refugia-based strategy for gastrointestinal nematodes on weight gain and fecal egg counts in naturally infected stocker calves administered combination anthelmintics

Refugia-based strategies associated with a combination of anthelmintic drugs belonging to different drug classes are becoming more common management practices to mitigate anthelmintic resistance (AR) in gastrointestinal nematodes (GIN) in small ruminants. Though refugia-based strategies have been largely demonstrated in small ruminants, cattle veterinarians and producers are considering such management strategies in grazing cattle production systems. Implementing refugia-based strategies lowers the amount of anthelmintics used in the herd and therefore slows the progression of AR by allowing a proportion of worms to escape drug selection pressure. The objective of this study was to observe the effect of a refugia-based strategy on body weight (BW), average daily gain (ADG) and fecal egg counts (FEC) of trichostongyle-type nematodes in naturally infected beef calves over a 131-day grazing season when compared with a whole herd treatment strategy, using the same combination of drugs. Stocker calves (n = 160) were ranked by body weight within sex then allocated to 16 paddocks, which were randomly assigned to one of two treatment groups. All calves in Group 1 (n = 80) were administered treatment, while in Group 2 (n = 80) the steer with the highest FEC in eggs per gram (EPG) within the paddock was left untreated. Treated calves received an extended release injectable 5 % eprinomectin (LongRange®, Boehringer Ingelheim Animal Health USA Inc.; 1 mL/50 kg of BW) and a 22.5 % oxfendazole oral suspension (Synanthic®, Boehringer Ingelheim Animal Health USA Inc.; 1 mL/50 kg of BW). Fecal egg counts and BW were recorded on days (D) −35, 0, 21, 131, and 148 to calculate the average fecal egg count reduction (FECR) and ADG for both groups. Linear mixed models, with paddock as the experimental unit, were used for analyses. The EPG differed on D21 (p < 0.01) and D131 (p = 0.057) with Group 2 having a higher average FEC (15.2 EPG D21; 57 EPG D131) compared with Group 1 (0.4 EPG D21; 37.25 EPG D131). However, there was no significant difference in average BW or ADG between treatment groups throughout the study. Results suggest refugia-based strategies could be implemented without significant negative impacts on average BW and ADG across other calves in the herd.

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Exploring the Relationship between Quantitative Reasoning Skills and News Habits

Because people are constantly confronted with numbers and mathematical concepts in the news, we have embarked on a project to create journalism that can support news users’ number skills. But doing so requires understanding (1) journalists’ ability to reason with numbers, (2) other adults’ ability to do so, and (3) the attributes and affordances of news. In this paper, we focus on the relationship between adults’ news habits and their quantitative reasoning skills. We collected data from a sample of 1,200 US adults, testing their ability to interpret statistical results and asking them to report their news habits. The assessment we developed differentiated the skills of adults in our sample and conformed to the theoretical and statistical assumption that such skills are normally distributed in the population overall. We also found that respondents could be clustered into six distinct groups on the basis of news repertoires (overall patterns of usage, including frequency of news use overall and choice of news outlets). As often assumed in the literature on quantitative reasoning, these news repertoires predicted quantitative reasoning skills better than the amount of quantification in the outlets, but they still predicted only a small fraction of the variance. These results may suggest that news habits may play a smaller or less direct role in quantitative reasoning than has previously been assumed. We speculate that the presence (or absence) of quantification in everyday activities – namely work and hobbies – may be a better predictor of adults’ quantitative reasoning, as may additional dimensions of news habits and affective responses to numbers.

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Resilient First Responder Paging via ATSC 3.0/NEXT GEN TV

Many Emergency Medical Service (EMS) and Fire services across the United States still rely on analog voice paging technology to communicate emergency incident information to responders. The infrastructure for these paging systems is typically owned, operated, and maintained by the local government or agency to ensure coverage includes as close to 100% of the jurisdiction as possible. This paper proposes the use of datacasting technology to provide a redundant method for critical data distribution over a wide area to serve the paging needs of public safety and uses North Carolina as a test case. This concept could lead to cost-sharing, higher reliability, greater collaboration across jurisdictions, and reduced response times. The public deserves the best possible response from the public safety sector and therefore, public safety deserves the best technology available in order to achieve their mission. PBS North Carolina, along with the North Carolina Department of Information Technology First Responder Emerging Technologies Program (FirstTech), presented this concept at the 2019 National Association of Broadcasters (NAB) Broadcast Engineering and Information Technology Conference. Much progress has been made since then. Starting in early 2020, a United States Department of Homeland Security Small Business Innovation Research grant was awarded to develop a prototype system that included an encoder and a custom ATSC 3.0 paging receiver with a miniature antenna. This paper will discuss the overall concept and current progress using ATSC 3.0 to address a critical emergency communications need [1].

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Characterization of the Aeration and Hydrodynamics in Vertical-Wheel™ Bioreactors.

In this work, the oxygen transport and hydrodynamic flow of the PBS Vertical-Wheel MINI™ 0.1 bioreactor were characterized using experimental data and computational fluid dynamics simulations. Data acquired from spectroscopy-based oxygenation measurements was compared with data obtained from 3D simulations with a rigid-lid approximation and LES-WALE turbulence modeling, using the open-source software OpenFOAM-8. The mass transfer coefficients were determined for a range of stirring speeds between 10 and 100 rpm and for working volumes between 60 and 100 mL. Additionally, boundary condition, mesh refinement, and temperature variation studies were performed. Lastly, cell size, energy dissipation rate, and shear stress fields were calculated to determine optimal hydrodynamic conditions for culture. The experimental results demonstrate that the can be predicted using , with a mean absolute error of 2.08%. Using the simulations and a correction factor of 0.473, the expression can be correlated to provide equally valid results. To directly obtain them from simulations, a partial slip boundary condition can be tuned, ensuring better near-surface velocity profiles or, alternatively, by deeply refining the mesh. Temperature variation studies support the use of this correlation for temperatures up to 37 °C by using a Schmidt exponent of 1/3. Finally, the flow was characterized as transitional with diverse mixing mechanisms that ensure homogeneity and suspension quality, and the results obtained are in agreement with previous studies that employed RANS models. Overall, this work provides new data regarding oxygen mass transfer and hydrodynamics in the Vertical-Wheel bioreactor, as well as new insights for air-water mass transfer modeling in systems with low interface deformation, and a computational model that can be used for further studies.

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Phenotypic, metabolic, and biogenesis properties of human stem cell-derived cerebellar spheroids

Human cerebellum consists of high density and complexity of neurons. Thus, it is challenging to differentiate cerebellar-like organoids with similar cellular markers and function to the human brain. Our previous study showed that the combination of retinoic acid (RA), Wingless/integrated (Wnt) activator, and Sonic Hedgehog (SHH) activator promotes cerebellar differentiation from human induced pluripotent stem cells (hiPSCs). This study examined phenotypic, metabolic, and biogenesis in early cerebellar development. Cerebellum spheroids were differentiated from human iPSK3 cells. During day 7–14, RA and Wnt activator CHIR99021 were used and SHH activator purmorphamine (PMR) was added later to promote ventralization. Gene expression for early cerebellar layer markers, metabolism, and extracellular vesicle (EV) biogenesis were characterized. Zinc-induced neurotoxicity was investigated as a proof-of-concept of neurotoxicity study. Flow cytometry results showed that there was no significant difference in NEPH3, PTF1A, OLIG2, and MATH1 protein expression between RCP (RA-CHIR-PMR) versus the control condition. However, the expression of cerebellar genes for the molecular layer (BHLE22), the granule cell layer (GABRB2, PAX6, TMEM266, KCNIP4), the Bergmann glial cells (QK1, DAO), and the Purkinje cell layer (ARHGEF33, KIT, MX1, MYH10, PPP1R17, SCGN) was significantly higher in the RCP condition than the control. The shift in metabolic pathways toward glycolysis was observed for RCP condition. The EV biogenesis marker expression was retained. Mild zinc-induced neurotoxicity may exist when zinc exposure exceeds 1.0 µM. RCP treatment can promote specific cerebellar-like differentiation from hiPSCs indicated by gene expression of early cerebellar markers and regionally enriched genes. The higher cerebellar marker expression is accompanied by the elevated glycolysis with the retained EV biogenesis. This study should advance the understanding of biomarkers during early cerebellar development for cerebellum organoid engineering and neurotoxicity study.

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Nutrition-related care needs of older patients in hospital: A qualitative multimethod study.

To investigate the nutrition-related care needs of older patients in hospitals. A qualitative multimethod study was performed. By purposive sampling, older patients were included for observations of the nutrition process and interviews from a perioperative unit, an internal Medicine unit, and one acute geriatric care ward of an acute care hospital. Preliminary findings were discussed, validated, and further explored in two focus group discussions with interprofessional nutritional healthcare experts. Seventeen women and five men with a mean age of 86 years participated in patient observations and interviews. Eight experts with at least 10 years of professional experience who were employed in this setting for 3 years or more participated in interviews. Three themes of nutrition-related care needs were elaborated: The need to assess and address older patients' attitudes toward life, the need for nutrition-related education, and the need for food intake support. These care needs added to the development and validation of a new nursing diagnosis "risk for inadequate protein energy nutrition" and in consequence to develop a complex nursing intervention to optimize the nutrition of older patients. It is crucial to assess and understand the patients' attitudes toward life, which affect purposes of treatment, diet, and menu choices. Implementation of assessing nutrition-related care needs of older inpatients is needed. Addressing these care needs within the Advanced Nursing Process can lead to appropriate nursing diagnoses, nursing outcomes, and interventions, which enhance person-centered care, patients' self-care abilities, and consequently patients' nutritional status.

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