scholarly journals Spheroid Trapping and Calcium Spike Estimation Techniques toward Automation of 3D Culture

Author(s):  
Kenneth Ndyabawe ◽  
Mark Haidekker ◽  
Amish Asthana ◽  
William S. Kisaalita

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.

2020 ◽  
Author(s):  
Laurence Silpa ◽  
Maximilian Schuessler ◽  
Gu Liu ◽  
Marcus Olivecrona ◽  
Lucia Groizard-Payeras ◽  
...  

AbstractThe large-scale and cost-effective production of quality-controlled human pluripotent stem cells (hPSC) for use in cell therapy and drug discovery requires chemically-defined xenobiotic-free culture systems that enable easy and homogeneous expansion of pluripotent cells. Through phenotypic screening, we have identified a small molecule, OXS8360 (an optimized derivative of (-)-Indolactam V ((-)-ILV)), that stably disrupts hPSC cell-cell contacts. Proliferation of hPSC in OXS8360 is normal, as are pluripotency signatures, directed differentiation to hallmark lineages and karyotype over extended passaging. In 3D culture, OXS8360-treated hPSC form smaller, more uniform aggregates, that are easier to dissociate, greatly facilitating expansion. The mode of action of OXS8360 involves disruption of the localisation of the cell-cell adhesion molecule E-cadherin, via activation of unconventional Protein Kinase C isoforms. OXS8360 media supplementation is therefore able to yield more uniform, disaggregated 2D and 3D hPSC cultures, providing the hPSC field with an affordable tool to improve hPSC quality and scalability.


2021 ◽  
pp. 039139882098680
Author(s):  
Xuefeng Zhang ◽  
Nan Wang ◽  
Yuhua Huang ◽  
Yan Li ◽  
Gang Li ◽  
...  

Background: Three-dimensional (3D) culture has been reported to increase the therapeutic potential of mesenchymal stem cells (MSCs). The present study assessed the therapeutic efficacy of extracellular vesicles (EVs) from 3D cultures of human placental MSCs (hPMSCs) for acute kidney injury (AKI). Methods: The supernatants from monolayer culture (2D) and 3D culture of hPMSCs were ultra-centrifuged for EVs isolation. C57BL/6 male mice were submitted to 45 min bilateral ischemia of kidney, followed by renal intra-capsular administration of EVs within a 72 h reperfusion period. Histological, immunohistochemical, and ELISA analyses of kidney samples were performed to evaluate cell death and inflammation. Kidney function was evaluated by measuring serum creatinine and urea nitrogen. The miRNA expression profiles of EVs from 2D and 3D culture of hPMSCs were evaluated using miRNA microarray analysis. Results: The 3D culture of hPMSCs formed spheroids with different diameters depending on the cell density seeded. The hPMSCs produced significantly more EVs in 3D culture than in 2D culture. More importantly, injection of EVs from 3D culture of hPMSCs into mouse kidney with ischemia-reperfusion (I/R)-AKI was more beneficial in protecting from progression of I/R than those from 2D culture. The EVs from 3D culture of hPMSCs were more efficient against apoptosis and inflammation than those from 2D culture, which resulted in a reduction in tissue damage and amelioration of renal function. MicroRNA profiling analysis revealed that a set of microRNAs were significantly changed in EVs from 3D culture of hPMSCs, especially miR-93-5p. Conclusion: The EVs from 3D culture of hPMSCs have therapeutic potential for I/R-AKI.


2021 ◽  
Vol 22 (12) ◽  
pp. 6394
Author(s):  
Jacob Spinnen ◽  
Lennard K. Shopperly ◽  
Carsten Rendenbach ◽  
Anja A. Kühl ◽  
Ufuk Sentürk ◽  
...  

For in vitro modeling of human joints, osteochondral explants represent an acceptable compromise between conventional cell culture and animal models. However, the scarcity of native human joint tissue poses a challenge for experiments requiring high numbers of samples and makes the method rather unsuitable for toxicity analyses and dosing studies. To scale their application, we developed a novel method that allows the preparation of up to 100 explant cultures from a single human sample with a simple setup. Explants were cultured for 21 days, stimulated with TNF-α or TGF-β3, and analyzed for cell viability, gene expression and histological changes. Tissue cell viability remained stable at >90% for three weeks. Proteoglycan levels and gene expression of COL2A1, ACAN and COMP were maintained for 14 days before decreasing. TNF-α and TGF-β3 caused dose-dependent changes in cartilage marker gene expression as early as 7 days. Histologically, cultures under TNF-α stimulation showed a 32% reduction in proteoglycans, detachment of collagen fibers and cell swelling after 7 days. In conclusion, thin osteochondral slice cultures behaved analogously to conventional punch explants despite cell stress exerted during fabrication. In pharmacological testing, both the shorter diffusion distance and the lack of need for serum in the culture suggest a positive effect on sensitivity. The ease of fabrication and the scalability of the sample number make this manufacturing method a promising platform for large-scale preclinical testing in joint research.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Stephan Payr ◽  
Elizabeth Rosado-Balmayor ◽  
Thomas Tiefenboeck ◽  
Tim Schuseil ◽  
Marina Unger ◽  
...  

Abstract Background The aim of this study was the investigation of the osteogenic potential of human osteoblasts of advanced donor age in 2D and 3D culture. Methods Osteoblasts were induced to osteogenic differentiation and cultivated, using the same polystyrene material in 2D and 3D culture for 2 weeks. Samples were taken to evaluate alkaline phosphatase (ALP) activity, mineralization and gene expression. Results Osteoprotegerin (OPG) levels were significantly increased (8.2-fold) on day 7 in 3D compared to day 0 (p < 0.0001) and 11.6-fold higher in 3D than in 2D (p < 0.0001). Both culture systems showed reduced osteocalcin (OC) levels (2D 85% and 3D 50% of basic value). Collagen type 1 (Col1) expression was elevated in 3D on day 7 (1.4-fold; p = 0.009). Osteopontin (OP) expression showed 6.5-fold higher levels on day 7 (p = 0.002) in 3D than in 2D. Mineralization was significantly higher in 3D on day 14 (p = 0.0002). Conclusion Advanced donor age human primary osteoblasts reveal significantly higher gene expression levels of OPG, Col1 and OP in 3D than in monolayer. Therefore, it seems that a relatively high potential of bone formation in a natural 3D arrangement is presumably still present in osteoblasts of elderly people. Trial registration 5217/11 on the 22nd of Dec. 2011.


2021 ◽  
Vol 8 (1) ◽  
pp. 11
Author(s):  
Sorel E. De Leon ◽  
Lana Cleuren ◽  
Zay Yar Oo ◽  
Paul R. Stoddart ◽  
Sally L. McArthur

Three-dimensional (3D) cell cultures have recently emerged as tools for biologically modelling the human body. As 3D models make their way into laboratories there is a need to develop characterisation techniques that are sensitive enough to monitor the cells in real time and without the need for chemical labels. Impedance spectroscopy has been shown to address both of these challenges, but there has been little research into the full impedance spectrum and how the different components of the system affect the impedance signal. Here we investigate the impedance of human fibroblast cells in 2D and 3D collagen gel cultures across a broad range of frequencies (10 Hz to 5 MHz) using a commercial well with in-plane electrodes. At low frequencies in both 2D and 3D models it was observed that protein adsorption influences the magnitude of the impedance for the cell-free samples. This effect was eliminated once cells were introduced to the systems. Cell proliferation could be monitored in 2D at intermediate frequencies (30 kHz). However, the in-plane electrodes were unable to detect any changes in the impedance at any frequency when the cells were cultured in the 3D collagen gel. The results suggest that in designing impedance measurement devices, both the nature and distribution of the cells within the 3D culture as well as the architecture of the electrodes are key variables.


2019 ◽  
Vol 500 (1) ◽  
pp. 531-549 ◽  
Author(s):  
Suzanne Bull ◽  
Joseph A. Cartwright

AbstractThis study shows how simple structural restoration of a discrete submarine landslide lobe can be applied to large-scale, multi-phase examples to identify different phases of slide-lobe development and evaluate their mode of emplacement. We present the most detailed analysis performed to date on a zone of intense contractional deformation, historically referred to as the compression zone, from the giant, multi-phase Storegga Slide, offshore Norway. 2D and 3D seismic data and bathymetry data show that the zone of large-scale (>650 m thick) contractional deformation can be genetically linked updip with a zone of intense depletion across a distance of 135 km. Quantification of depletion and accumulation along a representative dip-section reveals that significant depletion in the proximal region is not accommodated in the relatively mild amount (c. 5%) of downdip shortening. Dip-section restoration indicates a later, separate stage of deformation may have involved removal of a significant volume of material as part of the final stages of the Storegga Slide, as opposed to the minor volumes reported in previous studies.


2017 ◽  
Vol 14 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Suhaeb A. Mahmod ◽  
Simmrat Snigh ◽  
Ivan Djordjevic ◽  
Yong Mei Yee ◽  
Rohana Yusof ◽  
...  

Author(s):  
Guang-Zhen Jin

Abstract Among many factors of controlling stem cell differentiation, the key transcription factor upregulation via physical force is a good strategy on the lineage-specific differentiation of stem cells. The study aimed to compare growth and myogenic potentials between the parental cells (PCs) and the 1-day-old C2C12 spheroid-derived cells (SDCs) in two-dimensional (2D) and three-dimensional (3D) culture conditions through examination of the cell proliferation and the expression of myogenic genes. The data showed that 1-day-old spheroids had more intense expression of MyoD gene with respect to the PCs. The proliferation of the SDCs significantly higher than the PCs in a time dependent manner. The SDCs had also significantly higher myogenic potential than the PCs in 2D and 3D culture conditions. The results suggest that MyoD gene upregulation through cell-cell contacts is the good approach for preparation of seed cells in muscle tissue engineering.


2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Alfred S. Song ◽  
Amer M. Najjar ◽  
Kenneth R. Diller

This study was conducted to compare the heat shock responses of cells grown in 2D and 3D culture environments as indicated by the level of heat shock protein 70 expression and the incidence of apoptosis and necrosis of prostate cancer cell lines in response to graded hyperthermia. PC3 cells were stably transduced with a dual reporter system composed of two tandem expression cassettes—a conditional heat shock protein promoter driving the expression of green fluorescent protein (HSPp-GFP) and a cytomegalovirus (CMV) promoter controlling the constitutive expression of a “beacon” red fluorescent protein (CMVp-RFP). Two-dimensional and three-dimensional cultures of PC3 prostate cancer cells were grown in 96-well plates for evaluation of their time-dependent response to supraphysiological temperature. To induce controlled hyperthermia, culture plates were placed on a flat copper surface of a circulating water manifold that maintained the specimens within ±0.1 °C of a target temperature. Hyperthermia protocols included various combinations of temperature, ranging from 37 °C to 57 °C, and exposure times of up to 2 h. The majority of protocols were focused on temperature and time permutations, where the response gradient was greatest. Post-treatment analysis by flow cytometry analysis was used to measure the incidences of apoptosis (annexin V-FITC stain), necrosis (propidium iodide (PI) stain), and HSP70 transcription (GFP expression). Cells grown in 3D compared with 2D culture showed reduced incidence of apoptosis and necrosis and a higher level of HSP70 expression in response to heat shock at the temperatures tested. Cells responded differently to hyperthermia when grown in 2D and 3D cultures. Three-dimensional culture appears to enhance survival plausibly by activating protective processes related to enhanced-HSP70 expression. These differences highlight the importance of selecting physiologically relevant 3D models in assessing cellular responses to hyperthermia in experimental settings.


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