Browsing by Author "Ndyabawe, Kenneth"
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Item 3D Nerve Cell Cultures and Complex Physiological Relevance(Drug Discovery Today, 2018) Cheng, Xin; Ndyabawe, Kenneth; Asthana, Amish; Kisaalita, William S.The field of tissue engineering has not yet provided knowledge on which a consensus for the complex physiological relevance (CPR) of neuronal cultures could be established. The CPR of 3D neuronal cultures can have a profound impact on the drug discovery process through the validation of in vitro models for the study of neuropsychiatric and degenerative diseases, as well as screening for neurotoxicity during drug development. Herein, we assemble evidence in support of the potential of [Ca 2+] i oscillation frequency as a CPR outcome that can demonstrate the in vivo-like behavior of 3D cultures and differentiate them from 2D monolayers. We demonstrate that [Ca 2+] i oscillation frequencies in 2D cultures are significantly higher than those found in 3D cultures, and provide a possible molecular explanation.Item Biogas-powered evaporative cooling for smallholder dairy farmers’ evening milk: Zeolite characterization and regeneration(Sustainable Energy Technologies and Assessments, 2019) Ndyabawe, Kenneth; Brush, Ryan; Ssonko, Richard E.; Kisaalita, William S.A low-capacity (15.5-L) evaporative cooler, utilizing zeolite as an adsorbent, for saving smallholder dairy farmers’ evening milk, was not well received due several factors, addressed in the second generation higher capacity (>50 L) design. Like the first generation the new design uses zeolite and is powered by biogas. The first development step was to establish a protocol for testing commercially available zeolites to determine zeolite suitability for use in the design and to characterize the performance of a zeolite biogas-powered regenerator. Using an in-house developed protocol, zeolite beads of diameters 2.5–5 mm were tested and we found that 10 angstrom (Å) zeolites have a higher water adsorption capacity (6–7%) in comparison to 3 Å zeolite beads, suggesting that larger pore zeolites provide higher cooling capacity. However, large pore zeolite beads showed up to 18 times variance in repeat water adsorption compared to 3 Å zeolite, indicating that zeolite of small pores may provide more cooling cycles. Our biogas powered regenerator achieved and maintained the regeneration temperature of 200 °C when tested with both propane and biogas. This result affirms that our system can be operated on the farm using biogas as the energy source.Item Brain-on-a-Chip Device for Modeling Multiregional Networks(ACS Biomaterials Science & Engineering, 2020) Ndyabawe, Kenneth; Cipriano, Michael; Zhao, Wujun; Haidekker, Mark; Yao, Kun; Mao, Leidong; Kisaalita, William S.Animal models are frequently used in drug discovery because they represent a mammalian in vivo model system, they are the closest approximation to the human brain, and experimentation in humans is not ethical. Working with postmortem human brain samples is challenging and developing human in vitro systems, which mimic the in vivo human brain, has been challenging. However, the use of animal models in drug discovery for human neurological diseases is currently under scrutiny because data from animal models has come with variations due to genetic differences. Evidence from the literature suggests that techniques to reconstruct multiple neurotransmission projections, which characterize neurological disease circuits in humans, in vitro, have not been demonstrated. This paper presents a multicompartment microdevice for patterning neurospheres and specification of neural stem cell fate toward networks of multiple neuronal phenotypes. We validated our design by specification of human neural stem cells to dopaminergic and GABAergic neurons in different compartments of the device, simultaneously. The neurospheres formed unrestricted robust neuronal circuits between arrays of neurospheres in all compartments of the device. Such a device design may provide a basis for formation of multineurotransmission circuits to model functional connectivity between specific human brain regions, in vitro, using human-derived neural stem cells. This work finds relevance in neurological disease modeling and drug screening using human cell-based assays and may provide the impetus for shifting from animal-based models.Item Diffusion of an Evaporative Cooler Innovation Among Smallholder Dairy Farmers of Western Uganda(International Journal of Agricultural and Biological Engineering, 2014) Ndyabawe, Kenneth; Kisaalita, William S.In many sub-Saharan countries’ dairy industries, the evening milk is either wasted or processed into low-value products because it is highly perishable and cannot be kept fresh until the next morning, when it is safe to travel (no access to electricity and night travel is unsafe). To save this milk, a “bottom of the economic pyramid” solution in a low capacity (15.5 L), evaporative cooler has been developed and its performance has been assessed while initiating its diffusion among smallholder dairy farmers of Western Uganda. The cooler successfully preserved the milk over 24 h period with acceptable quality in terms of the Resazurin test scale. Although the rate of the cooler innovation diffusion was found consistent with other diffusion studies in rural settings, interviews of participants suggested that a larger capacity cooler (50–100 L) and on-farm regeneration with biogas will accelerate the diffusion rate, affirming that at the micro-level, societal shaping of technology is indispensable to successful diffusionItem Engineering Q3 microsystems to recapitulate brain physiology on a chip(Drug discovery today, 2019) Ndyabawe, Kenneth; Kisaalita, William S.The structural and functional organization of the human brain consists of 52 regions with distinct cellular organization. In vitro models for normal and pathological states using isolated brain-region-specific 3D engineered tissues fail to recapitulate information integration and/or transfer that arises from connectivity among neuroanatomical structures. Therefore, development of brain-on-a-chip microsystems must shift to multiple region neuron network designs to be relevant in brain functionality and deficit modeling. However, in vitro formation of multiregional networks on microdevices presents several challenges that we illustrate using a few neurological disorders; and we offer guidance, depending on objectives (HTS, disease modeling, etc.) for rational design of microfluidic systems and better emulation of in vivo conditions.Item Secretome-Based Prediction of Three-Dimensional Hepatic Microtissue Physiological Relevance(ACS Biomaterials Science & Engineering, 2019) Asthana, Amish; White, Charles M.; Ndyabawe, Kenneth; Douglass, Megan; Kisaalita, William S.Early biomarkers for indication of the complex physiological relevance (CPR) of a three-dimensional (3D) tissue model are needed. CPR is detected late in culture and requires different analytical techniques. Albumin production, CYP3A4 expression, and formation of bile canaliculi structures are commonly used to compare in vitro hepatic cells to their in vivo counterpart. A universal biomarker independent of the cell type would bring this to a common detection platform. We make the case that these hepatic characteristics are not sufficient to differentiate traditional (2D) cell culture from the more complex 3D culture. We explored the cytokine secretion profile (secretome) for its potential as a 3D early culture biomarker. PDGF-AB/BB and vascular endothelial growth factor (VEGF) were found to be upregulated in 3D compared to 2D cultures at early time points (days 3 and 4). These observations provide a foundation upon which in vivo validation of cytokines can lead to physiologically relevant 3D in vitro cell culture.Item Spheroid Trapping and Calcium Spike Estimation Techniques toward Automation of 3D Culture(SLAS TECHNOLOGY: Translating Life Sciences Innovation, 2021) Ndyabawe, Kenneth; Haidekker, Mark; Asthana, Amish; Kisaalita, William S.We present a spheroid trapping device, compatible with traditional tissue culture plates, to confine microtissues in a small area and allow suspension cultures to be treated like adherent cultures with minimal loss of spheroids due to aspiration. We also illustrate an automated morphology-independent procedure for cell recognition, segmentation, and a calcium spike detection technique for high-throughput analysis in 3D cultured tissue. Our cell recognition technique uses a maximum intensity projection of spatial-temporal data to create a binary mask, which delineates individual cell boundaries and extracts mean fluorescent data for each cell through a series of intensity thresholding and cluster labeling operations. The temporal data are subject to sorting for imaging artifacts, baseline correction, smoothing, and spike detection algorithms. We validated this procedure through analysis of calcium data from 2D and 3D SHSY-5Y cell cultures. Using this approach, we rapidly created regions of interest (ROIs) and extracted fluorescent intensity data from hundreds of cells in the field of view with superior data fidelity over hand-drawn ROIs even in dense (3D tissue) cell populations. We sorted data from cells with imaging artifacts (such as photo bleaching and dye saturation), classified nonfiring and firing cells, estimated the number of spikes in each cell, and documented the results, facilitating large-scale calcium imaging analysis in both 2D and 3D cultures. Since our recognition and segmentation technique is independent of morphology, our protocol provides a versatile platform for the analysis of large confocal calcium imaging data from neuronal cells, glial cells, and other cell types.Item Validity of the Africa-wide Lang Factor of 2.63 for Estimating Small Biogas Plant Installation Costs in Uganda(International Journal of Agricultural and Biological Engineering, 2014) Ndyabawe, Kenneth; Kisaalita, William S.There is an increasing interest in popularizing small biogas plants to meet the bulk of domestic energy needs in Africa for cooking, lighting, and other activities such as cooling or refrigeration. As stakeholders (policy makers, donors, credit providers, sector experts, and product development professionals) contemplate programs, one of the key questions to which a reliable answer is needed is biogas plant installation cost that may vary from region to region. An Africa-wide materialsItem Validity of the Africa-wide Lang factor of 2.63 for estimating small biogas plant installation costs in Uganda(International Journal of Agricultural and Biological Engineering, 2014) Ndyabawe, Kenneth; Kisaalita, William S.There is an increasing interest in popularizing small biogas plants to meet the bulk of domestic energy needs in Africa for cooking, lighting, and other activities such as cooling or refrigeration. As stakeholders (policy makers, donors, credit providers, sector experts, and product development professionals) contemplate programs, one of the key questions to which a reliable answer is needed is biogas plant installation cost that may vary from region to region. An Africa-wide materials’ cost multiplier factor (Lang factor of 2.63) estimation approach has been proposed, based on data from only two locations. The factor’s validity throughout Africa has been questioned. This study shows that the Africa-wide Lang factor of 2.63 is applicable in Uganda. However, differences in accuracy have been observed based on whether the installation is located in a rural or urban setting. Location-specific factors of 2.984 and 2.404 for rural and urban locations were established and validated, respectively, which produced more accurate estimates in comparison with a single composite non-location specific factor.