Bioengineered in vitro models of leukocyte–vascular interactions

2021 ◽  
Author(s):  
Jaehyun Lee ◽  
Cort B. Breuer ◽  
Esak Lee
Keyword(s):  
Lymphatic Vessels ◽  
In Vitro Models ◽  
Model Systems ◽  
Future Research ◽  
Interstitial Tissue ◽  
Leukocyte Trafficking ◽  
Tissue Space ◽  
Spatiotemporal Analyses

Leukocytes continuously circulate our body through the blood and lymphatic vessels. To survey invaders or abnormalities and defend our body against them, blood-circulating leukocytes migrate from the blood vessels into the interstitial tissue space (leukocyte extravasation) and exit the interstitial tissue space through draining lymphatic vessels (leukocyte intravasation). In the process of leukocyte trafficking, leukocytes recognize and respond to multiple biophysical and biochemical cues in these vascular microenvironments to determine adequate migration and adhesion pathways. As leukocyte trafficking is an essential part of the immune system and is involved in numerous immune diseases and related immunotherapies, researchers have attempted to identify the key biophysical and biochemical factors that might be responsible for leukocyte migration, adhesion, and trafficking. Although intravital live imaging of in vivo animal models has been remarkably advanced and utilized, bioengineered in vitro models that recapitulate complicated in vivo vascular structure and microenvironments are needed to better understand leukocyte trafficking since these in vitro models better allow for spatiotemporal analyses of leukocyte behaviors, decoupling of interdependent biological factors, better controlling of experimental parameters, reproducible experiments, and quantitative cellular analyses. This review discusses bioengineered in vitro model systems that are developed to study leukocyte interactions with complex microenvironments of blood and lymphatic vessels. This review focuses on the emerging concepts and methods in generating relevant biophysical and biochemical cues. Finally, the review concludes with expert perspectives on the future research directions for investigating leukocyte and vascular biology using the in vitro models.

scholarly journals Blood and Lymphatic Vasculatures On-Chip Platforms and Their Applications for Organ-Specific In Vitro Modeling

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 147 ◽  
Author(s):  
Aria R. Henderson ◽  
Hyoann Choi ◽  
Esak Lee
Keyword(s):  
Cardiovascular System ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
In Vitro Models ◽  
The Body ◽  
Interstitial Tissue ◽  
Organ Specific ◽  
On Chip

The human circulatory system is divided into two complementary and different systems, the cardiovascular and the lymphatic system. The cardiovascular system is mainly concerned with providing nutrients to the body via blood and transporting wastes away from the tissues to be released from the body. The lymphatic system focuses on the transport of fluid, cells, and lipid from interstitial tissue spaces to lymph nodes and, ultimately, to the cardiovascular system, as well as helps coordinate interstitial fluid and lipid homeostasis and immune responses. In addition to having distinct structures from each other, each system also has organ-specific variations throughout the body and both systems play important roles in maintaining homeostasis. Dysfunction of either system leads to devastating and potentially fatal diseases, warranting accurate models of both blood and lymphatic vessels for better studies. As these models also require physiological flow (luminal and interstitial), extracellular matrix conditions, dimensionality, chemotactic biochemical gradient, and stiffness, to better reflect in vivo, three dimensional (3D) microfluidic (on-a-chip) devices are promising platforms to model human physiology and pathology. In this review, we discuss the heterogeneity of both blood and lymphatic vessels, as well as current in vitro models. We, then, explore the organ-specific features of each system with examples in the gut and the brain and the implications of dysfunction of either vasculature in these organs. We close the review with discussions on current in vitro models for specific diseases with an emphasis on on-chip techniques.

Abstract 5402: Two Photon Microscopy Measurements Of Sub-epicardial Sarcomere Length In Perfused Rat Hearts

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Patrizia Camelliti ◽  
Gil Bub ◽  
Daniel J Stuckey ◽  
Christian Bollensdorff ◽  
Damian J Tyler ◽  
...  
Keyword(s):  
Sarcomere Length ◽  
Left Ventricular ◽  
Model Systems ◽  
Future Research ◽  
Fundamental Parameter ◽  
Rat Hearts ◽  
Perfused Hearts ◽  
Over Time

Sarcomere length (SL) is a fundamental parameter underlying the Frank Starling relation in the heart, as it offers an absolute representation of myocardial stretch. Previous studies addressed the Frank Starling relation by measuring SL in isolated myocytes or muscle strips. Here, we report first data obtained using a novel technique to measure sub-epicardial SL in perfused hearts. Rat hearts were Langendorff perfused (normal Tyrode solution) at a constant pressure of 90mmHg, labeled with the fluorescent membrane marker di-4-ANEPPS, and then arrested with high-K + Tyrode for either 2-photon microscopy (n=4) or MRI (n=4). Image analysis software was developed to extract SL at the cell level from >1,400 2-photon images (Fig 1 ) and correct for cell angle. SL increased by 10±2 % between 30 and 80 min of perfusion (1.98±0.04 to 2.17±0.03 μm; p<0.05; Fig 1 ). Measurements of left ventricular myocardial volume (LVMV) were made in vivo and in perfused hearts using 3D MRI. LVMV increased by 24±7% from in vivo to 30 min of perfusion, and by 11±3 % between 30 and 90 min (539±35; 664±44; 737±49 mm 3 , respectively; p<0.05; Fig 1 ). We show that SL can be measured in isolated perfused hearts. The method allowed monitoring of changes in SL over time, and showed that SL and LVMV increase to a similar extent during 30–80 min perfusion with crystalloid solution, probably due to tissue oedema. This result, together with the increase in LVMV during the first 30 min, highlights the pronounced differences between in vivo , in situ , and in vitro model systems for studies of cardiac physiology and mechanics. Future research will compare changes in SL in healthy hearts and disease models involving contractile dysfunction. Figure 1: Left: 2-photon microscopy image of di-4-ANEPPS labeled myocardium. Right: SL and LVMV changes over time.

Demonstration of subpopulations with differing cancer stem cell phenotypes in xenograft and in vitro models of colorectal liver metastases.

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 394-394
Author(s):  
Dominic E. Sanford ◽  
Andrew Giorgi ◽  
Brian D. Goetz ◽  
Roheena Z. Panni ◽  
William G. Hawkins ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Liver Metastases ◽  
In Vitro Models ◽  
Model Systems ◽  
Cell Populations ◽  
Tumor Initiating Cells ◽  
Distinct Cell

394 Background: Tumors are composed of heterogeneous cell populations, some of which demonstrate enhanced tumor-forming capabilities (so-called tumor initiating cells [TIC] or cancer stem cells). In colorectal cancer (CRC), CD133, 44, and 24 are cell surface markers that identify TIC. Therefore, we sought to determine if CRC liver metastases (CRC-LM) form xenografts (in vivo) and cell cultures (in vitro) with TIC markers. Methods: CRC-LM were grafted in NOD/SCID mice and passaged serially. Xenografts were mechanically dissociated and cultured under sphere forming conditions. Flow cytometry was performed for TIC phenotype. Results: 16 of 18 (89%) CRC-LM specimens formed tumors in mice. Xenografts formed EpCAM+ tumors and spheres. The frequency of CD133+, CD44+, and CD133+/CD44+ tumor cells were 55%, 33%, and 23%, respectively. There was a subpopulation of CD133+/CD44+ cells with elevated CD44 expression(CD44hi). This CD133+/CD44hi population was also CD24+; representing 5% of cells. Eight of eleven (73%) xenografts formed spheres in vitro. The frequency of CD133+, CD44+, and CD133+/CD44+ cells were 63%, 47%, and 26%, respectively. CD133+/CD44+/CD24+ cells made up 8% of sphere-forming cells. There was a non-significant trend towards increased frequency of CD133+, CD44+, and CD133/CD44 positive cells in the spheres compared to the xenografts. However, the percentage of CD133+/CD44+/CD24+ cells was significantly increased in spheres relative to xenografts (8% vs. 5%, respectively; p<0.05) (see Table). Conclusions: CRC-LM derived xenografts and spheres are composed of distinct cell populations with differing levels of TIC/cancer stem cells. Sphere cultures may enhance for the most enriched TIC population. Thus, xenografts and sphere cultures are important model systems to further study the importance of cancer stem cells in CRC progression and metastases. [Table: see text]

scholarly journals Complementarity of clinical trials, model systems, and metabolomic workflow to unravel the healthy effects of foods: BEBESANO vs MODELSANO: A case study

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Vicente Agulló ◽  
◽  
Raúl Domínguez-Perles ◽  
Cristina García-Viguera ◽  
◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Ex Vivo ◽  
In Vitro Models ◽  
Experimental Models ◽  
Model Systems ◽  
Food Science ◽  
Clinical Models ◽  
Safe Condition

Nowadays, the health benefits associated with the consumption of plant-based food constitute a hot topic. To further demonstrate such benefits, related to antioxidant, anti-microbial, and anti-inflammatory activities, as well as the reduction of the risk of several pathophysiological conditions, the study of bioaccessibility and bioavailability of specific food’s constituents, which require interdisciplinary networks, is essential. In this frame, although different experimental models can be developed, the workflow described in the present work support the application of intervention trials in humans as the first option to study the truly effects on health of foods (e.g., plant-based foods), due to the safe condition of them and the realistic approach of this kind of studies, later explored in depth resorting to in vitro, ex vivo, and pre-clinical models, as the most appropriate workflow to get reliable results in the field of Food Science and Nutrition, regarding mechanisms of actions and molecular interactions. Thereby, the work described in the present review is developed in the frame of two consecutive and interconnected projects: BEBESANO (concluded) and MODELSANO (in process) that demonstrate the efficiency of the workflow proposed for research in the Food Science and Nutrition fields. In this regard, in the frame of BEBESANO, acute and longitudinal interventions in humans, devoted to set-up bioavailability of bioactive compounds, followed by functional studies in vivo upon pre-clinical models were conducted to unravel the relationship between bioactive compounds in plant-based beverages and the use of sweetener replacer. Now, most relevant findings from BEBESANO are being further explored in the newly granted project MODELSANO, which is aimed to uncover gaps of knowledge about the mechanisms behind the descriptive results obtained in BEBESANO, using more restrictive in vitro models (allowing the development of studies on the cellular and molecular pathways involved), and integrative cutting edge mathematical modelling alternatives. Keywords: In vivo; in vitro; bioavailability; bioaccessibility; bioactivity; health-promoting foods; metabolomic; mechanistic studies

scholarly journals A Brief Review of In Vitro Models for Injury and Regeneration in the Peripheral Nervous System

2022 ◽  
Vol 23 (2) ◽  
pp. 816
Author(s):  
Parvathi Varier ◽  
Gayathri Raju ◽  
Pallavi Madhusudanan ◽  
Chinnu Jerard ◽  
Sahadev A. Shankarappa
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Nerve Injury ◽  
Axonal Injury ◽  
In Vitro Models ◽  
Model Systems ◽  
Neural Regeneration ◽  
Post Injury

Nerve axonal injury and associated cellular mechanisms leading to peripheral nerve damage are important topics of research necessary for reducing disability and enhancing quality of life. Model systems that mimic the biological changes that occur during human nerve injury are crucial for the identification of cellular responses, screening of novel therapeutic molecules, and design of neural regeneration strategies. In addition to in vivo and mathematical models, in vitro axonal injury models provide a simple, robust, and reductionist platform to partially understand nerve injury pathogenesis and regeneration. In recent years, there have been several advances related to in vitro techniques that focus on the utilization of custom-fabricated cell culture chambers, microfluidic chamber systems, and injury techniques such as laser ablation and axonal stretching. These developments seem to reflect a gradual and natural progression towards understanding molecular and signaling events at an individual axon and neuronal-soma level. In this review, we attempt to categorize and discuss various in vitro models of injury relevant to the peripheral nervous system and highlight their strengths, weaknesses, and opportunities. Such models will help to recreate the post-injury microenvironment and aid in the development of therapeutic strategies that can accelerate nerve repair.

scholarly journals Organs-on-a-Chip Module: A Review from the Development and Applications Perspective

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 536 ◽  
Author(s):  
Juan Eduardo Sosa-Hernández ◽  
Angel M. Villalba-Rodríguez ◽  
Kenya D. Romero-Castillo ◽  
Mauricio A. Aguilar-Aguila-Isaías ◽  
Isaac E. García-Reyes ◽  
...  
Keyword(s):  
Model Systems ◽  
Proper Function ◽  
Future Research ◽  
High Tech ◽  
In Vivo Models ◽  
Engineering Research ◽  
Microfluidic Technology ◽  
Wide Range

In recent years, ever-increasing scientific knowledge and modern high-tech advancements in micro- and nano-scales fabrication technologies have impacted significantly on various scientific fields. A micro-level approach so-called “microfluidic technology” has rapidly evolved as a powerful tool for numerous applications with special reference to bioengineering and biomedical engineering research. Therefore, a transformative effect has been felt, for instance, in biological sample handling, analyte sensing cell-based assay, tissue engineering, molecular diagnostics, and drug screening, etc. Besides such huge multi-functional potentialities, microfluidic technology also offers the opportunity to mimic different organs to address the complexity of animal-based testing models effectively. The combination of fluid physics along with three-dimensional (3-D) cell compartmentalization has sustained popularity as organ-on-a-chip. In this context, simple humanoid model systems which are important for a wide range of research fields rely on the development of a microfluidic system. The basic idea is to provide an artificial testing subject that resembles the human body in every aspect. For instance, drug testing in the pharma industry is crucial to assure proper function. Development of microfluidic-based technology bridges the gap between in vitro and in vivo models offering new approaches to research in medicine, biology, and pharmacology, among others. This is also because microfluidic-based 3-D niche has enormous potential to accommodate cells/tissues to create a physiologically relevant environment, thus, bridge/fill in the gap between extensively studied animal models and human-based clinical trials. This review highlights principles, fabrication techniques, and recent progress of organs-on-chip research. Herein, we also point out some opportunities for microfluidic technology in the future research which is still infancy to accurately design, address and mimic the in vivo niche.

scholarly journals Simvastatin mediates inhibition of exosome synthesis, localization and secretion via multicomponent interventions

2018 ◽  
Author(s):  
Ankur Kulshreshtha ◽  
Swati Singh ◽  
Kritika Khanna ◽  
Anurag Agrawal ◽  
Balaram Ghosh
Keyword(s):  
Important Implication ◽  
Biological Fluids ◽  
In Vitro Models ◽  
Model Systems ◽  
Biological Processes ◽  
Exosome Biogenesis ◽  
Health And Disease ◽  
Multicomponent Interventions

AbstractDiscovery of exosomes as modulator of cellular communication has added a new dimension to our understanding of biological processes. Exosomes influence the biological systems by mediating trans-communication across tissues and cells, which has important implication for health and disease. Identification of strategies for exosome modulation may pave the way towards better understanding of exosome biology and development of novel therapeutics. In absence of well-characterized modulators of exosome biogenesis, an alternative option is to target pathways generating important exosomal components. Cholesterol represents one such essential component required for exosomal biogenesis. We initiated this study to test the hypothesis that owing to its cholesterol lowering effect, simvastatin, a HMG CoA inhibitor, might be able to alter exosome formation and secretion. Using previously established protocols for detecting secreted exosomes in biological fluids, simvastatin was tested for its effect on exosome secretion under various in-vitro and in-vivo settings. Murine model of AAI was used for further validation of our findings. Utilizing aforementioned systems, we demonstrate exosome-lowering potential of simvastatin in various in-vivo and in-vitro models, of AAI and atherosclerosis. We believe that the knowledge acquired in this study holds potential for extension to other exosome dominated pathologies and model systems.

scholarly journals Use of in vitro bone models to screen for altered bone metabolism, osteopathies, and fracture healing: challenges of complex models

2020 ◽  
Vol 94 (12) ◽  
pp. 3937-3958
Author(s):  
Sabrina Ehnert ◽  
Helen Rinderknecht ◽  
Romina H. Aspera-Werz ◽  
Victor Häussling ◽  
Andreas K. Nussler
Keyword(s):  
Fracture Healing ◽  
Bone Metabolism ◽  
Ex Vivo ◽  
In Vitro Models ◽  
Complex Model ◽  
Model Systems ◽  
Full Potential ◽  
In Vivo Models

Abstract Approx. every third hospitalized patient in Europe suffers from musculoskeletal injuries or diseases. Up to 20% of these patients need costly surgical revisions after delayed or impaired fracture healing. Reasons for this are the severity of the trauma, individual factors, e.g, the patients’ age, individual lifestyle, chronic diseases, medication, and, over 70 diseases that negatively affect the bone quality. To investigate the various disease constellations and/or develop new treatment strategies, many in vivo, ex vivo, and in vitro models can be applied. Analyzing these various models more closely, it is obvious that many of them have limits and/or restrictions. Undoubtedly, in vivo models most completely represent the biological situation. Besides possible species-specific differences, ethical concerns may question the use of in vivo models especially for large screening approaches. Challenging whether ex vivo or in vitro bone models can be used as an adequate replacement for such screenings, we here summarize the advantages and challenges of frequently used ex vivo and in vitro bone models to study disturbed bone metabolism and fracture healing. Using own examples, we discuss the common challenge of cell-specific normalization of data obtained from more complex in vitro models as one example of the analytical limits which lower the full potential of these complex model systems.

In Vitro Testing of Neurotoxicity

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 153-179
Author(s):  
Erik Walum ◽  
Elisabeth Hansson ◽  
Alan L. Harvey
Keyword(s):  
Nervous System ◽  
Ex Vivo ◽  
Cell Types ◽  
Biochemical Properties ◽  
In Vitro Models ◽  
Model Systems ◽  
Culture Methods ◽  
Developmental Potential

Many of the toxic compounds that are at large in the environment represent a risk to our neuronal functions. Chemicals may have a direct or indirect effect on the nervous system and they may interfere with general biochemical properties or specific neuronal structures and processes. In this review, a brief presentation of the major neurotoxicological targets is given, together with a discussion of some aspects of the use of different in vitro models for screening purposes and mechanistic studies. It is believed that in vitro methods offer special opportunities for the development of new neurotoxicological assays, and that this development will mainly involve cultured model systems. Therefore, a presentation of nerve and glia tissue culture methods is given, followed by an overview of how information on the action of mercury and mercurials, excitotoxins and acrylamide has been obtained through the use of cultured cell models. It is concluded that the developmental potential in cell neurotoxicology lies within the areas of separation and identification of cells representative for different structures in the nervous system, co-cultivation of different cell types, in vivo/in vitro (ex vivo) procedures, chemically defined media, metabolic competent cultures of human cells and improved physiological conditions for cultivation and exposure.

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