scholarly journals Microfluidic Live-Imaging Technology to Perform Research Activities in 3D Models

Author(s):  
Arnaud Martino Capuzzo ◽  
Daniele Vigo

One of the most surprising differences observed when comparing cell cultures in 2D and 3D is morphological dissimilarity and their evolution over time. Cells grown in a monolayer tend to flatten in the lower part of the plate adhering to and spreading in the horizontal plane without expanding in the vertical dimension. The result is that cells grown in 2D have a forced apex-basal polarity. 3D cultures support co-cultivation and crosstalking between multiple cell types, which regulate development and formation in the in vivo counterpart. 3D models culture, with or without a scaffold matrix, can exhibit more in vivo-like morphology and physiology. 3D cultures recapitulate relevant physiological cellular processes, transforming into unique platforms for drug screening. To support and guarantee the functional maintenance of a 3D structure, one must consider the structures and dynamics of regulatory networks, increasingly studied with liveimaging microscopy. However, commercially available technologies that can be used for current laboratory needs are limited, although there is a need to facilitate the acquisition of cellular kinetics with a high spatial and temporal resolution, to elevate visual performance and consequently that of experimentation. The CELLviewer is a newly conceived and developed multi-technology instrumentation, combining and synchronizing the work of different scientific disciplines. This 2 work aims to test the system with two models: the first model is a single Jurkat cell while the second is an MCF-7 spheroid. After having grown both models, the two models used are loaded into the microfluidic cartridge for each experiment and recorded in time-lapse for a total of 4 hours. After adaptive autofocus, when sliding inside the cartridge chamber, the samples used are tracked under the action of the optics and the 3D rotation was experimentally successfully obtained. A cell viability assessment was then used using the MitoGreen dye, a fluorescence marker selectively permeable to live cells. The ImageJ software was used to: calculate the model diameter, create fluorescence intensity graphs along a straight line passing through the cell, visualize the spatial fluorescence intensity distribution in 3D.

2021 ◽  
Author(s):  
Capuzzo Arnaud Martino ◽  
Daniele Vigo

ABSTRACTOne of the most surprising differences observed when comparing cell cultures in 2D and 3D is morphological dissimilarity and their evolution over time. Cells grown in a monolayer tend to flatten in the lower part of the plate adhering to and spreading in the horizontal plane without expanding in the vertical dimension. The result is that cells grown in 2D have a forced apex-basal polarity. 3D cultures support co-cultivation and crosstalking between multiple cell types, which regulate development and formation in the in vivo counterpart. 3D models culture, with or without a scaffold matrix, can exhibit more in vivo-like morphology and physiology. 3D cultures recapitulate relevant physiological cellular processes, transforming into unique platforms for drug screening. To support and guarantee the functional maintenance of a 3D structure, one must consider the structures and dynamics of regulatory networks, increasingly studied with live-imaging microscopy. However, commercially available technologies that can be used for current laboratory needs are limited, although there is a need to facilitate the acquisition of cellular kinetics with a high spatial and temporal resolution, to elevate visual performance and consequently that of experimentation. The CELLviewer is a newly conceived and developed multi-technology instrumentation, combining and synchronizing the work of different scientific disciplines. This work aims to test the system with two models: the first model is a single Jurkat cell while the second is an MCF-7 spheroid. After having grown both models, the two models used are loaded into the microfluidic cartridge for each experiment and recorded in time-lapse for a total of 4 hours. After adaptive autofocus, when sliding inside the cartridge chamber, the samples used are tracked under the action of the optics and the 3D rotation was experimentally successfully obtained. A cell viability assessment was then used using the MitoGreen dye, a fluorescence marker selectively permeable to live cells. The ImageJ software was used to: calculate the model diameter, create fluorescence intensity graphs along a straight line passing through the cell, visualize the spatial fluorescence intensity distribution in 3D.


Author(s):  
Arnaud Martino Capuzzo ◽  
Daniele Vigo

Morphological dissimilarity and its evolution over time are one of the most unexpected variations found when comparing cell cultures in 2D and 3D. Monolayer cells appear to flatten in the lower part of the plate, adhering to and spreading in the horizontal plane while not extending vertically. Consequently, cells developed in two dimensions have a forced apex-basal polarity. Co-cultivation and crosstalking between multiple cell types, which control development and formation in the in vivo counterpart, are possible in 3D cultures. With or without a scaffold matrix, 3D model culture may exhibit more in vivo-like morphology and physiology. 3D cultures mimic relevant physiological cellular processes, transforming them into one-of-a-kind drug screening platforms. The structures and dynamics of regulatory networks, which are increasingly studied with live-imaging microscopy, must be considered to help and guarantee the functional maintenance of a 3D structure. However, commercially available technologies that can be used for current laboratory needs are minimal, despite the need to make it easier to acquire cellular kinetics with high spatial and temporal resolution, in order to improve visual efficiency and, as a result, experimentation performance. The CELLviewer is a newly developed multi-technology instrument that integrates and synchronizes the work of various scientific disciplines. The aim of this study is to test the device using two different models: a single Jurkat cell and an MCF-7 spheroid. The two models are loaded into the microfluidic cartridge for each experiment after they have been grown and captured in time-lapse for a total of 4 hours. The samples used are tracked under the operation of the optics after adaptive autofocus, while slipping inside the cartridge chamber, and the 3D rotation was successfully obtained experimentally. The MitoGreen dye, a fluorescence marker selectively permeable to live cells, was then used to determine cell viability. To measure the model diameter, construct fluorescence intensity graphs along a straight line passing through the cell, and visualize the spatial fluorescence intensity distribution in 3D, ImageJ software was used.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Capuzzo Arnaud Martino

Morphological dissimilarity and its evolution over time are one of the most unexpected variations found when comparing cell cultures in 2D and 3D. Monolayer cells appear to flatten in the lower part of the plate, adhering to and spreading in the horizontal plane while not extending vertically. Consequently, cells developed in two dimensions have a forced apex-basal polarity. Co-cultivation and crosstalking between multiple cell types, which control development and formation in the in vivo counterpart, are possible in 3D cultures. With or without a scaffold matrix, 3D model culture may exhibit more in vivo-like morphology and physiology. 3D cultures mimic relevant physiological cellular processes, transforming them into one-of-akind drug screening platforms. The structures and dynamics of regulatory networks, which are increasingly studied with live-imaging microscopy, must be considered to help and guarantee the functional maintenance of a 3D structure. However, commercially available technologies that can be used for current laboratory needs are minimal, despite the need to make it easier to acquire cellular kinetics with high spatial and temporal resolution, in order to improve visual efficiency and, as a result, experimentation performance. The CELLviewer is a newly developed multi-technology instrument that integrates and synchronizes the work of various scientific disciplines. The aim of this study is to test the device using two different models: a single Jurkat cell and an MCF-7 1 spheroid. The two models are loaded into the microfluidic cartridge for each experiment after they have been grown and captured in time-lapse for a total of 4 hours. The samples used are tracked under the operation of the optics after adaptive autofocus, while slipping inside the cartridge chamber and the 3D rotation was successfully obtained experimentally. The MitoGreen dye, a fluorescence marker selectively permeable to live cells, was then used to determine cell viability. To measure the model diameter, construct fluorescence intensity graphs along a straight line passing through the cell, and visualize the spatial fluorescence intensity distribution in 3D, Image J software was used.


2017 ◽  
Vol 215 (1) ◽  
pp. 233-248 ◽  
Author(s):  
Christina Eich ◽  
Jochen Arlt ◽  
Chris S. Vink ◽  
Parham Solaimani Kartalaei ◽  
Polynikis Kaimakis ◽  
...  

Cell fate is established through coordinated gene expression programs in individual cells. Regulatory networks that include the Gata2 transcription factor play central roles in hematopoietic fate establishment. Although Gata2 is essential to the embryonic development and function of hematopoietic stem cells that form the adult hierarchy, little is known about the in vivo expression dynamics of Gata2 in single cells. Here, we examine Gata2 expression in single aortic cells as they establish hematopoietic fate in Gata2Venus mouse embryos. Time-lapse imaging reveals rapid pulsatile level changes in Gata2 reporter expression in cells undergoing endothelial-to-hematopoietic transition. Moreover, Gata2 reporter pulsatile expression is dramatically altered in Gata2+/− aortic cells, which undergo fewer transitions and are reduced in hematopoietic potential. Our novel finding of dynamic pulsatile expression of Gata2 suggests a highly unstable genetic state in single cells concomitant with their transition to hematopoietic fate. This reinforces the notion that threshold levels of Gata2 influence fate establishment and has implications for transcription factor–related hematologic dysfunctions.


Blood ◽  
2010 ◽  
Vol 115 (22) ◽  
pp. 4412-4420 ◽  
Author(s):  
Diana Matheoud ◽  
Leila Perié ◽  
Guillaume Hoeffel ◽  
Lene Vimeux ◽  
Isabelle Parent ◽  
...  

Abstract Cross-presentation is an essential mechanism that allows dendritic cells (DCs) to efficiently present exogenous antigens to CD8+ T cells. Among cellular antigen sources, apoptotic cells are commonly considered as the best for cross-presentation by DCs. However, the potential of live cells as a source of antigen has been overlooked. Here we explored whether DCs were able to capture and cross-present antigens from live cells. DCs internalized cytosolic and membrane material into vesicles from metabolically labeled live cells. Using time-lapse confocal microscopy in whole spleens, we showed that DCs internalized material from live cells in vivo. After ovalbumin uptake from live cells, DCs cross-primed ovalbumin-specific naive OT-I CD8+ T cells in vitro. Injected into mice previously transferred with naive OT-I T cells, they also cross-primed in vivo, even in the absence of endogenous DCs able to present the epitope in the recipient mice. Interestingly, DCs induced stronger natural CD8+ T-cell responses and protection against a lethal tumor challenge after capture of antigens from live melanoma cells than from apoptotic melanoma cells. The potential for cross-presentation from live cells uncovers a new type of cellular intercommunication and must be taken into account for induction of tolerance or immunity against self, tumors, grafts, or pathogens.


2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Kristy L. Nowak-Lovato ◽  
Kirk D. Rector

This review captures the use of live cells as dynamic microlaboratories through implementation of labeled nanoparticles (nanosensors) that have both sensing and targeting functions. The addition of 2,4-ε-dinitrophenol-L-lysine (DNP) as a FcεRI targeting ligand and 4-mercaptopyridine (4-MPy) as a pH-sensing ligand enables spatial and temporal monitoring of FcεRI receptors and their pH environment within the endocytic pathway. To ensure reliability, the sensor is calibratedin vivousing the ionophore nigericin and standard buffer solutions to equilibrate the external[H+]concentration with that of the cell compartments. This review highlights the nanosensors, ability to traffic and respond to pH of receptor-bound nanosensors (1) at physiological temperature(37°C)versus room temperature(25°C), (2) after pharmacological treatment with bafilomycin, anH+ATPase pump inhibitor, or amiloride, an inhibitor ofNa+/H+exchange, and (3) in response to both temperature and pharmacological treatment. Whole-cell, time lapse images are demonstrated to show the ability to transform live cells into dynamic laboratories to monitor temporal and spatial endosomal pH. The versatility of these probes shows promise for future applications relevant to intracellular trafficking and intelligent drug design.


Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 6033
Author(s):  
Sarai Martinez-Pacheco ◽  
Lorraine O’Driscoll

To develop and subsequently get cancer researchers to use organotypic three-dimensional (3D) models that can recapitulate the complexity of human in vivo tumors in an in vitro setting, it is important to establish what in vitro model(s) researchers are currently using and the reasons why. Thus, we developed a survey on this topic, obtained ethics approval, and circulated it throughout the world. The survey was completed by 101 researchers, across all career stages, in academia, clinical or industry settings. It included 40 questions, many with multiple options. Respondents reported on their field of cancer research; type of cancers studied; use of two-dimensional (2D)/monolayer, 2.5D and/or 3D cultures; if using co-cultures, the cell types(s) they co-culture; if using 3D cultures, whether these involve culturing the cells in a particular way to generate spheroids, or if they use additional supports/scaffolds; techniques used to analyze the 2D/2.5D/3D; and their downstream applications. Most researchers (>66%) only use 2D cultures, mainly due to lack of experience and costs. Despite most cancer researchers currently not using the 3D format, >80% recognize their importance and would like to progress to using 3D models. This suggests an urgent need to standardize reliable, robust, reproducible methods for establishing cost-effective 3D cell culture models and their subsequent characterization.


Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


Author(s):  
E. D. Salmon ◽  
J. C. Waters ◽  
C. Waterman-Storer

We have developed a multi-mode digital imaging system which acquires images with a cooled CCD camera (Figure 1). A multiple band pass dichromatic mirror and robotically controlled filter wheels provide wavelength selection for epi-fluorescence. Shutters select illumination either by epi-fluorescence or by transmitted light for phase contrast or DIC. Many of our experiments involve investigations of spindle assembly dynamics and chromosome movements in live cells or unfixed reconstituted preparations in vitro in which photodamage and phototoxicity are major concerns. As a consequence, a major factor in the design was optical efficiency: achieving the highest image quality with the least number of illumination photons. This principle applies to both epi-fluorescence and transmitted light imaging modes. In living cells and extracts, microtubules are visualized using X-rhodamine labeled tubulin. Photoactivation of C2CF-fluorescein labeled tubulin is used to locally mark microtubules in studies of microtubule dynamics and translocation. Chromosomes are labeled with DAPI or Hoechst DNA intercalating dyes.


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