Imaging Microphysiological Systems: A Review

Author(s):  
Samantha Peel ◽  
Mark Jackman

Microphysiological Systems (MPS), often referred to as 'organ-on-chips' are microfluidic-based in vitro models that aim to recapitulate the dynamic chemical and mechanical microenvironment of living organs. MPS promise to bridge the gap between in vitro and in vivo models, and ultimately improve the translation from pre-clinical animal studies to clinical trials. However, despite the explosion of interest in recent years, and the obvious rewards for such models which could improve R&D efficiency and reduce drug attrition in the clinic, the pharmaceutical industry has been slow to fully adopt this technology. The ability to extract robust, quantitative information from MPS at scale is a key requirement if these models are to impact drug discovery and the subsequent drug development process. Microscopy imaging remains a core technology that enables the capture of information at the single cell level and with subcellular resolution. Furthermore, such imaging techniques can be automated, increasing throughput, enabling compound screening. In this review we discuss a range of imaging techniques that have been applied to MPS of varying focus, such as organoids and organ-chip-type models. We outline the opportunities these technologies can bring in terms of understanding mechanistic biology, but also how they could be used in higher-throughput screens, widening the scope of their impact in drug discovery. We discuss the associated challenges of imaging these complex models and the steps required to enable full exploitation. Finally, we discuss the requirements for MPS, if they are to be applied at a scale necessary to support drug discovery projects.

2020 ◽  
Vol 57 (3) ◽  
pp. 358-368
Author(s):  
Radhakrishna Sura ◽  
Terry Van Vleet ◽  
Brian R. Berridge

High-throughput in vitro models lack human-relevant complexity, which undermines their ability to accurately mimic in vivo biologic and pathologic responses. The emergence of microphysiological systems (MPS) presents an opportunity to revolutionize in vitro modeling for both basic biomedical research and applied drug discovery. The MPS platform has been an area of interdisciplinary collaboration to develop new, predictive, and reliable in vitro methods for regulatory acceptance. The current MPS models have been developed to recapitulate an organ or tissue on a smaller scale. However, the complexity of these models (ie, including all cell types present in the in vivo tissue) with appropriate structural, functional, and biochemical attributes are often not fully characterized. Here, we provide an overview of the capabilities and limitations of the microfluidic MPS model (aka organs-on-chips) within the scope of drug development. We recommend the engagement of pathologists early in the MPS design, characterization, and validation phases, because this will enable development of more robust and comprehensive MPS models that can accurately replicate normal biology and pathophysiology and hence be more predictive of human responses.


Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tsui-Chin Wang ◽  
Jung-Chung Lin ◽  
Jen-Chang Chang ◽  
Ya-Wen Hiaso ◽  
Ching-Hsun Wang ◽  
...  

Abstract Background Two different types of hypervirulent K. pneumoniae (HvKp), the MLST-11 and serotype K1/K2 strains, have been frequently described in recent studies. Although these two types of strains were described to be HvKp, their virulence was not compared. In this study, in vitro and in vivo approaches were used to assess differences in virulence. Materials and methods A total of twenty-nine isolates, including 6 strains of each of serotype K1 and K2 isolates and 17 strains of ST11 isolates, were selected for this study. Phenotypic tests of virulence were performed by the string test and analysis of the virulent associated genes was detected by PCR. In vitro models of serum resistance and phagocytosis were used as the parameters to assess the virulence. In-frame deletion of virulence-associated genes was performed to study their contributions to virulence. The median lethal dose, i.e., the LD50, in mice was determined following IP injection. Results Although serotype K1 and K2 strains and ST11 isolates had similar virulence gene profiles, the ST11 isolates showed less serum and phagocytic resistance than the serotype K1/K2 isolates. The mouse lethality test revealed that all ST11 isolates were unable to cause lethality, even at > 107 CFU, while serotypes K1 and K2 showed an LD50 at ≤ 103 CFU. Aerobactin or capsule knockout mutants exhibited a lower LD50 than the parental strain, while capsule mutants showed a more significant decrease in LD50. Conclusion Since there was a significant difference in virulence levels between the two types of HvKp when assessed in in vitro and in vivo models, it may be better to use the designation "HvKp" for some strains based on animal studies to avoid confusion. Virulence and non-virulence could be analysed in a relative manner, especially in comparison studies.


2020 ◽  
Vol 20 ◽  
Author(s):  
Nur Najmi Mohamad Anuar ◽  
Nurul Iman Natasya Zulkafali ◽  
Azizah Ugusman

: Matrix metalloproteinases (MMPs) are a group of zinc-dependent metallo-endopeptidase that are responsible towards the degradation, repair and remodelling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic and food industries. This review summarises the current knowledge on plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signalling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviours, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.


Author(s):  
Sara Mantero ◽  
Federica Boschetti

Bioreactors are powerful tools for in vitro development of engineered substitutes through controlled biological, physical, and mechanical culture conditions: bioreactor technology allows a closer in vitro replication of native tissues. One of bioreactors applications is the design of in vitro 3D tissue models as a bridge between 2D and in vivo models, allowing the application of 3R (replacement, reduction, refinement) principle. To this aim, bioreactors can be used to culture cells seeded on engineered scaffolds under in vivo-like conditions. Another key use of bioreactors is for perfusion decellularization of tissues and organs to be used as scaffolds. This contribution describes a dynamic stretching. bioreactor, imposing a mechanical stretching to the cultured constructs, allowing the development of skeletal muscle engineered constructs, and a decellularization bioreactor, designed for decellularization of blood vessels.


Author(s):  
Verônica Assalin Zorgetto-Pinheiro ◽  
Alexandre Meira de Vasconcelos ◽  
Rafael Sanaiotte Pinheiro ◽  
Danielle Bogo ◽  
Iandara Schettert Silva

Rheumatoid arthritis is an autoimmune and chronic pathological condition characterized by an inflammatory process of the joints It is a complex and multifactorial, involving genetic, epigenetic and environmental factors and the use of experimental models is required to better understand its pathology and for drug testing. The aim of this study was to perform a systematic literature review on experimental models in rheumatoid arthritis using IRAMUTEQ, a software that analysis, qualitatively and quantitatively, text fragments, as a methodological tool. After searching for articles published in the last five years on Scopus database and applying the exclusion criteria, we ended with 84 articles. The most commonly employed experimental models was the arthritis induction by inoculation of the Complete Freund's Adjuvant (CFA), followed by the use of combined methodologies and the collagen-induced arthritis (CIA). The analyses of abstracts by the IRAMUTEQ software provided a classification according to their textual elements in four classes, which were grouped into three main themes: in vivo models (class 1), clinical practice and traditional medicine (classes 2 and 3) and in vitro models (class 4) and it was also possible to build a similarity tree of the terms present in the abstracts and a word cloud with the most cited terms. Thus, the use of the IRAMUTEQ software as a methodological tool has been satisfactory, since it was possible to identify the main experimental models used, keywords, pathological processes and molecules involved in the pathogenesis of rheumatoid arthritis free of the researchers’ bias, in addition to being a tool for visual and intuitive results.


Author(s):  
Loh Teng Hern Tan ◽  
Liang Ee Low ◽  
Siah Ying Tang ◽  
Wei Hsum Yap ◽  
Lay Hong Chuah ◽  
...  

Three-dimensional cell culture methods revolutionize the field of anticancer drug discovery, forming an important link-bridge between conventional in vitro and in vivo models and conferring significant clinical and biological relevant data. The current work presents an affordable yet reproducible method of generating homogenous 3D tumor spheroids. Also, a new open source software is adapted to perform an automated image analysis of 3D tumor spheroids and subsequently generate a list of morphological parameters of which could be utilized to determine the response of these spheroids toward treatments. Our data showed that this work could serve as a reliable 3D cell culture platform for preclinical cytotoxicity testing of natural products prior to the expensive and time-consuming animal models


Author(s):  
Arianna Manini ◽  
Leonardo Pantoni

AbstractCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic disease caused by NOTCH3 mutations and characterized by typical clinical, neuroradiological, and pathological features. NOTCH3 belongs to a family of highly conserved transmembrane receptors rich of epidermal growth factor repeats, mostly expressed in vascular smooth muscle cells and pericytes, which perform essential developmental functions and are involved in tissues maintenance and renewal. To date, no therapeutic option for CADASIL is available except for few symptomatic treatments. Novel in vitro and in vivo models are continuously explored with the aim to investigate underlying pathogenic mechanisms and to test novel therapeutic approaches. In this scenario, knock-out, knock-in, and transgenic mice studies have generated a large amount of information on molecular and biological aspects of CADASIL, despite that they incompletely reproduce the human phenotype. Moreover, the field of in vitro models has been revolutionized in the last two decades by the introduction of induced pluripotent stem cells (iPSCs) technology. As a consequence, novel therapeutic approaches, including immunotherapy, growth factors administration, and antisense oligonucleotides, are currently under investigation. While waiting that further studies confirm the promising results obtained, the data reviewed suggest that our therapeutic approach to the disease could be transformed, generating new hope for the future.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 832
Author(s):  
Katherine E. Burns ◽  
Robert F. Uhrig ◽  
Maggie E. Jewett ◽  
Madison F. Bourbon ◽  
Kristen A. Krupa

Silver nanoparticles (AgNPs) are being employed in numerous consumer goods and applications; however, they are renowned for inducing negative cellular consequences including toxicity, oxidative stress, and an inflammatory response. Nanotoxicological outcomes are dependent on numerous factors, including physicochemical, biological, and environmental influences. Currently, NP safety evaluations are carried out in both cell-based in vitro and animal in vivo models, with poor correlation between these mechanisms. These discrepancies highlight the need for enhanced exposure environments, which retain the advantages of in vitro models but incorporate critical in vivo influences, such as fluid dynamics. This study characterized the effects of dynamic flow on AgNP behavior, cellular interactions, and oxidative stress within both adherent alveolar (A549) and suspension monocyte (U937) models. This study determined that the presence of physiologically relevant flow resulted in substantial modifications to AgNP cellular interactions and subsequent oxidative stress, as assessed via reactive oxygen species (ROS), glutathione levels, p53, NFκB, and secretion of pro-inflammatory cytokines. Within the adherent model, dynamic flow reduced AgNP deposition and oxidative stress markers by roughly 20%. However, due to increased frequency of contact, the suspension U937 cells were associated with higher NP interactions and intracellular stress under fluid flow exposure conditions. For example, the increased AgNP association resulted in a 50% increase in intracellular ROS and p53 levels. This work highlights the potential of modified in vitro systems to improve analysis of AgNP dosimetry and safety evaluations, including oxidative stress assessments.


2019 ◽  
Vol 64 (5) ◽  
pp. 299-307
Author(s):  
M. V. Fursov ◽  
I. A. Dyatlov ◽  
V. D. Potapov

Modeling of tuberculosis infection is carried out in order to clarify various aspects of the tuberculosis pathogenesis, as well as the testing of new anti-tuberculosis drugs. The characteristic of in vitro models (n = 16) for Mycobacterium tuberculosis dormant state and in vivo models (n = 14) for the latent tuberculosis infection involving several animal species published to date are presented in this review. A brief description of the models and the results obtained by the authors are presented. The analysis of the published data reflects the list of methodological procedures that allow researchers to study the mechanism of the transition of M. tuberculosis cells to a dormant state and reverse to metabolically active state, as well as the process of conversion of active tuberculosis infection to a latent tuberculosis and reactivation.


Toxics ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Tania Charette ◽  
Danyel Bueno Dalto ◽  
Maikel Rosabal ◽  
J. Jacques Matte ◽  
Marc Amyot

Fish consumption is the main exposure pathway of the neurotoxicant methylmercury (MeHg) in humans. The risk associated with exposure to MeHg may be modified by its interactions with selenium (Se) and arsenic (As). In vitro bioaccessibility studies have demonstrated that cooking the fish muscle decreases MeHg solubility markedly and, as a consequence, its potential absorption by the consumer. However, this phenomenon has yet to be validated by in vivo models. Our study aimed to test whether MeHg bioaccessibility can be used as a surrogate to assess the effect of cooking on MeHg in vivo availability. We fed pigs raw and cooked tuna meals and collected blood samples from catheters in the portal vein and carotid artery at: 0, 30, 60, 90, 120, 180, 240, 300, 360, 420, 480 and 540 min post-meal. In contrast to in vitro models, pig oral bioavailability of MeHg was not affected by cooking, although the MeHg kinetics of absorption was faster for the cooked meal than for the raw meal. We conclude that bioaccessibility should not be readily used as a direct surrogate for in vivo studies and that, in contrast with the in vitro results, the cooking of fish muscle did not decrease the exposure of the consumer to MeHg.


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