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This paper summarizes the outcome of the Organ-on-Chip (OoC) ORCHID Strategy workshop (Leiden, the Netherlands, 17 January 2019) intended to establish a European OoC roadmap through expert discussions, conclusions and recommendations. The workshop identified six specific building blocks for the OoC roadmap: (1) application, (2) specification, (3) qualification, (4) standardization, (5) production and upscaling, and (6) adoption. Complementary aspects relating to ethics and communication were also addressed. Priorities, methods and targets for the roadmap were proposed for each building block. General consensus was reached on the potential contribution of the newly founded European Organ-on-Chip Society (EUROoCS), which could facilitate deployment of each block. EUROoCS would ideally initiate and catalyze dialogue between OoC developers, end users and regulators. The dialogue should address qualification, open technology platforms, standardization and implementation of OoC technology, as well as ethical aspects of human tissue mimics, training the next generation of OoC researchers, dissemination and communication.

International audience; We present a new 3D lens-free microscope for large 3D biological samples and a dedicated reconstruction algorithm based on the Fourier diffraction theorem as used in standard diffractive tomography [1, 2]. It uses a regularised inverse problem formalism directly applied on the whole dataset and the 3D object to retrieve. To our knowledge, this is the first time that such an inverse problem approach is implemented in the context of lens-free diffractive tomography to reconstruct large volumes of unstained biological samples.

International audience; We discuss the current challenges and future prospects of flow-based organoid models and 3D self-assembling scaffolds. The existing paradigm of 3D culture suffers from a lack of control over organoid size and shape; can be an obstacle for cell harvesting and extended cellular and molecular analysis; and does not provide access to the function of exocrine glands. Moreover, existing organ-on-chip models are mostly composed of 2D extracellular matrix (ECM)-coated elastomeric membranes that do not mimic real organ architectures. A new comprehensive 3D toolbox for cell biology has emerged to address some of these issues. Advances in microfabrication and cell-culturing approaches enable the engineering of sophisticated models that mimic organ 3D architectures and physiological conditions, while supporting flow-based drug screening and secretomics-based diagnosis.TrendsMicrofluidics and microfabrication have revolutionized the way in which cells can be studied and manipulated in systems that are starting to provide 3D models and organ-on-chip devices.Individual-organ models and multiple-organ interaction models address the issue of how microengineered approaches can faithfully reproduce key elements of physiologically relevant microenvironments.The innovative technical nature of such 3D systems opens up exciting possibilities of answering several important fundamental biological questions that cannot be addressed with standard culture conditions.In the race to closely mimic the structural and physiological functions of human tissues and organs, new possibilities have emerged in the form of 3D organ-level structures that integrate dynamic mechanical cues as well as chemical signals.

This literature review describes the advantages of microfluidics when combined with electric methods in live cell analysis. We focus on dielectric spectroscopy of individual cells and classify methods according to the type of information they provide on the biological material examined and how this information can be used to guide the development of biosensors. We then describe methods for the direct measurement of electrophysiological activity of single cells through either integrated lab-on-chip patch clamp devices or communicating cellular networks with multi-electrode arrays. Lastly, we present our views on how a multimodal approach addresses the need for and challenge of tracking spatial and temporal determinants of cell activity at the cellular level.

The invention relates to a device for dispensing droplets comprising a first channel (8, 10), known as the main channel, for circulating a first liquid flow, a second channel (12, 13) for circulating fluid, forming an intersection area (27) with the first channel and being terminated by an ejection opening (20), means (4) for measuring a physical property of particles or cells in the first channel (18), and means for producing a pressure wave in the second channel (12,13).

Despite the possible common histopathological features at diagnosis, cancer cells present within breast carcinomas are highly heterogeneous in their molecular signatures. This heterogeneity is responsible for disparate clinical behaviors, treatment responses and long-term outcomes in breast cancer patients. Although the few histopathological markers can partially describe the diversity of cells found in tumor tissue sections, the full molecular characterization of individual cancer cells is currently impossible in routine clinical practice. In this respect, Fourier transform infrared (FTIR) microspectroscopic imaging of histological sections allows obtaining, for each pixel of tissue images, hundreds of independent potential markers, which makes this technique a particularly powerful tool to distinguish cell types and subtypes. As a complement to the conventional clinicopathological evaluation, this spectroscopic approach has the potential to directly reveal molecular descriptors that should allow identifying different clonal lineages found within a single tumor and therefore provide knowledge relevant to diagnosis, prognosis and treatment personalization. Yet, interpretation of infrared (IR) spectra acquired on tissue sections requires a well-established calibration, which is currently missing. Conventionally, mammary epithelial cells are studied in vitro as adherent two-dimensional (2D) monolayers, which lead to the alteration of cell-microenvironmental interplay and consequently to the loss of tissue structure and function. A number of key in vivo-like interactions may be re-established with the use of three-dimensional (3D) laminin-rich extracellular matrix (lrECM)-based culture systems. The aim of this thesis is to investigate by FTIR imaging the influence of the in vitro growth environment (2D culture versus 3D lrECM culture and 3D monoculture versus 3D co-culture with fibroblasts) on a series of thirteen well-characterized human breast cancer cell lines and to determine culture conditions generating spectral phenotypes that are closer to the ones observed in malignant breast tissues. The reference cell lines cultured in a physiologically relevant basement membrane model and having undergone formalin fixation, paraffin embedding (FFPE), a routine treatment used to preserve clinical tissue specimens, could contribute to the construction of a spectral database. The latter could be ultimately employed as a valuable tool to interpret IR spectra of cells present in tumor tissue sections, particularly through the recognition of unique spectral markers.To achieve the goal, we developed and optimized, in a first step, the preparation of samples derived from traditional 2D and 3D lrECM cell cultures in order to preserve their morphological and molecular relevance for FTIR microspectroscopic analysis. We then highlighted the importance of the influence of the growth environment on the cellular phenotype by comparing spectra of 2D- and 3D-cultured breast cancer cell lines between them. A particular focus was placed to establish a correlation between FTIR spectral data and publicly available microarray-based gene expression patterns of the whole series of breast cancer cell lines grown in 2D and 3D lrECM cultures. Our results revealed that, although based on completely different principles, gene expression profiling and FTIR spectroscopy are similarly sensitive to both the cell line identity and the phenotypes induced by cell culture conditions. We also identified by FTIR imaging changes in the chemical content occurring in the microenvironment surrounding cell spheroids grown in 3D lrECM culture model. Finally, we illustrated the impact of the in vivo-like microenvironment on the IR spectra of breast cancer cell lines grown in 3D lrECM co-culture with fibroblasts and compared them with spectra of cell lines grown in 3D lrECM monoculture. Unsupervised statistical data analyses reported that cells grown in 3D co-cultures produce spectral phenotypes similar to the ones observed in FFPE tumor tissue sections from breast carcinoma patients. Altogether, our results suggest that FFPE samples prepared from 3D lrECM cultures of breast cancer cell lines and studied by FTIR microspectroscopic imaging provide reliable information that could be integrated in the setting up of a recognition model aiming to identify and interpret specific spectral signatures of cells present in breast tumor tissue sections., Le cancer du sein est une maladie très hétérogène, tant au niveau clinique que biologique. Cette hétérogénéité rend impossible la caractérisation moléculaire complète des cellules cancéreuses individuelles dans la pratique clinique courante. Dans ce contexte, l’imagerie infrarouge à transformée de Fourier (FTIR) des coupes tissulaires permet d'obtenir pour chaque pixel d'une image de tissu des centaines de marqueurs potentiels indépendants, ce qui pourrait faire de cette technique un outil particulièrement puissant pour identifier des différents types et sous-types cellulaires. L'interprétation des spectres infrarouges (IR) enregistrés à partir des coupes histologiques nécessite cependant une calibration qui fait actuellement défaut. Cette calibration pourrait être obtenue à partir de lignées cellulaires tumorales bien caractérisées. Traditionnellement, les cellules épithéliales mammaires sont étudiées in vitro sous forme de monocouches adhérentes bidimensionnelles (2D), ce qui conduit à l'altération de la communication entre les cellules et leur environnement et, par conséquent, à la perte de l’architecture et de la fonction du tissu épithélial. Un certain nombre d'interactions physiologiques clés peuvent être rétablies en utilisant des systèmes de culture tridimensionnelle (3D) dans une matrice extracellulaire riche en laminine (lrECM). L'objectif de cette thèse consiste à étudier par imagerie FTIR l'influence du microenvironnement (via une comparaison entre les cultures 2D et 3D lrECM ou les cultures 3D lrECM en présence ou en l’absence de fibroblastes) sur une série de treize lignées de cellules tumorales mammaires humaines bien caractérisées et à déterminer les conditions de culture générant des phénotypes spectraux qui se rapprochent le plus de ceux observés dans les tissus tumoraux. Au cours de ce travail, nous avons mis au point la culture des lignées cellulaires dans un modèle 3D lrECM ainsi qu’une méthodologie de préparation des échantillons offrant la possibilité de les comparer de manière pertinente avec les cellules cancéreuses présentes dans les coupes histologiques. De même, nous avons étudié par imagerie FTIR les effets du microenvironnement sur les lignées de cellules tumorales et inversement. Pour les lignées investiguées, le passage d’une culture 2D à une culture 3D lrECM s’accompagne, en effet, de modifications du spectre IR étroitement corrélées aux modifications du transcriptome. Les marqueurs spectraux indiquent également que l’environnement 3D génère un phénotype cellulaire proche de celui trouvé dans les coupes histologiques. De manière intéressante, cette proximité est d’autant plus renforcée en présence de fibroblastes dans le milieu de culture., Doctorat en Sciences agronomiques et ingénierie biologique, info:eu-repo/semantics/nonPublished