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Biosensors Dec 2022Organs-on-chips (OoCs) are microfluidic devices that contain bioengineered tissues or parts of natural tissues or organs and can mimic the crucial structures and... (Review)
Review
Organs-on-chips (OoCs) are microfluidic devices that contain bioengineered tissues or parts of natural tissues or organs and can mimic the crucial structures and functions of living organisms. They are designed to control and maintain the cell- and tissue-specific microenvironment while also providing detailed feedback about the activities that are taking place. Bioprinting is an emerging technology for constructing artificial tissues or organ constructs by combining state-of-the-art 3D printing methods with biomaterials. The utilization of 3D bioprinting and cells patterning in OoC technologies reinforces the creation of more complex structures that can imitate the functions of a living organism in a more precise way. Here, we summarize the current 3D bioprinting techniques and we focus on the advantages of 3D bioprinting compared to traditional cell seeding in addition to the methods, materials, and applications of 3D bioprinting in the development of OoC microsystems.
Topics: Tissue Engineering; Bioprinting; Microphysiological Systems; Biocompatible Materials; Printing, Three-Dimensional
PubMed: 36551101
DOI: 10.3390/bios12121135 -
F1000Research 2018All multicellular organisms are colonized by microbes, but a gestalt study of the composition of microbiome communities and their influence on the ecology and evolution... (Review)
Review
All multicellular organisms are colonized by microbes, but a gestalt study of the composition of microbiome communities and their influence on the ecology and evolution of their macroscopic hosts has only recently become possible. One approach to thinking about the topic is to view the host-microbiome ecosystem as a "holobiont". Because natural selection acts on an organism's realized phenotype, and the phenotype of a holobiont is the result of the integrated activities of both the host and all of its microbiome inhabitants, it is reasonable to think that evolution can act at the level of the holobiont and cause changes in the "hologenome", or the collective genomic content of all the individual bionts within the holobiont. This relatively simple assertion has nevertheless been controversial within the microbiome community. Here, I provide a review of recent work on the hologenome concept of evolution. I attempt to provide a clear definition of the concept and its implications and to clarify common points of disagreement.
Topics: Animals; Biological Evolution; Biota; Genome; Humans; Microbiota; Phenotype; Selection, Genetic
PubMed: 30410727
DOI: 10.12688/f1000research.14385.1 -
The New Phytologist Sep 2015985 I. 985 II. 986 III. 987 IV. 988 V. 989 989 References 989 SUMMARY: The development of multicellular organisms depends on correct establishment of symmetry both at... (Review)
Review
985 I. 985 II. 986 III. 987 IV. 988 V. 989 989 References 989 SUMMARY: The development of multicellular organisms depends on correct establishment of symmetry both at the whole-body scale and within individual tissues and organs. Setting up planes of symmetry must rely on communication between cells that are located at a distance from each other within the organism, presumably via mobile morphogenic signals. Although symmetry in nature has fascinated scientists for centuries, it is only now that molecular data to unravel mechanisms of symmetry establishment are beginning to emerge. As an example we describe the genetic and hormonal interactions leading to an unusual bilateral-to-radial symmetry transition of an organ in order to promote reproduction.
Topics: Animals; Plant Development; Plants
PubMed: 26086581
DOI: 10.1111/nph.13526 -
Integrative and Comparative Biology Dec 2023Motility is an essential factor for an organism's survival and diversification. With the advent of novel single-cell technologies, analytical frameworks, and theoretical... (Review)
Review
Motility is an essential factor for an organism's survival and diversification. With the advent of novel single-cell technologies, analytical frameworks, and theoretical methods, we can begin to probe the complex lives of microscopic motile organisms and answer the intertwining biological and physical questions of how these diverse lifeforms navigate their surroundings. Herein, we summarize the main mechanisms of microscale motility and give an overview of different experimental, analytical, and mathematical methods used to study them across different scales encompassing the molecular-, individual-, to population-level. We identify transferable techniques, pressing challenges, and future directions in the field. This review can serve as a starting point for researchers who are interested in exploring and quantifying the movements of organisms in the microscale world.
Topics: Animals; Movement; Single-Cell Analysis; Models, Theoretical; Cell Movement; Bacteria
PubMed: 37336589
DOI: 10.1093/icb/icad075 -
Interface Focus Jun 2023Organisms are non-equilibrium, stationary systems self-organized via spontaneous symmetry breaking and undergoing metabolic cycles with broken detailed balance in the...
Organisms are non-equilibrium, stationary systems self-organized via spontaneous symmetry breaking and undergoing metabolic cycles with broken detailed balance in the environment. The thermodynamic free-energy (FE) principle describes an organism's homeostasis as the regulation of biochemical work constrained by the physical FE cost. By contrast, recent research in neuroscience and theoretical biology explains a higher organism's homeostasis and allostasis as Bayesian inference facilitated by the informational FE. As an integrated approach to living systems, this study presents an FE minimization theory overarching the essential features of both the thermodynamic and neuroscientific FE principles. Our results reveal that the perception and action of animals result from active inference entailed by FE minimization in the brain, and the brain operates as a Schrödinger's machine conducting the neural mechanics of minimizing sensory uncertainty. A parsimonious model suggests that the Bayesian brain develops the optimal trajectories in neural manifolds and induces a dynamic bifurcation between neural attractors in the process of active inference.
PubMed: 37065269
DOI: 10.1098/rsfs.2022.0041 -
Interface Focus Oct 2017The capacity of organisms to respond in their own lifetimes to new challenges in their environments probably appeared early in biological evolution. At present few... (Review)
Review
The capacity of organisms to respond in their own lifetimes to new challenges in their environments probably appeared early in biological evolution. At present few studies have shown how such adaptability could influence the inherited characteristics of an organism's descendants. In part, this has been because organisms have been treated as passive in evolution. Nevertheless, their effects on biological evolution are likely to have been important and, when they occurred, accelerated the pace of evolution. Ways in which this might have happened have been suggested many times since the 1870s. I review these proposals and discuss their relevance to modern thought.
PubMed: 28839914
DOI: 10.1098/rsfs.2016.0126 -
Tissue Engineering. Part B, Reviews Dec 2022Organoids, which are multicellular clusters with similar physiological functions to living organs, have gained increasing attention in bioengineering. As organoids... (Review)
Review
Organoids, which are multicellular clusters with similar physiological functions to living organs, have gained increasing attention in bioengineering. As organoids become more advanced, methods to form complex structures continue to develop. There is evidence that the extracellular microenvironment can regulate organoid quality. The extracellular microenvironment consists of soluble bioactive molecules, extracellular matrix, and biofluid flow. However, few efforts have been made to discuss the microenvironment optimal to engineer specific organoids. Therefore, this review article examines the extent to which engineered extracellular microenvironments regulate organoid quality. First, we summarize the natural tissue and organ's unique chemical and mechanical properties, guiding researchers to design an extracellular microenvironment used for organoid engineering. Then, we summarize how the microenvironments contribute to the formation and growth of the brain, lung, intestine, liver, retinal, and kidney organoids. The approaches to forming and evaluating the resulting organoids are also discussed in detail. Impact statement Organoids, which are multicellular clusters with similar physiological function to living organs, have been gaining increasing attention in bioengineering. As organoids become more advanced, methods to form complex structures continue to develop. This review article focuses on recent efforts to engineer the extracellular microenvironment in organoid research. We summarized the natural organ's microenvironment, which informs researchers of key factors that can influence organoid formation. Then, we summarize how these microenvironmental controls significantly contribute to the formation and growth of the corresponding brain, lung, intestine, liver, retinal, and kidney organoids. The approaches to forming and evaluating the resulting organoids are discussed in detail, including extracellular matrix choice and properties, culture methods, and the evaluation of the morphology and functionality through imaging and biochemical analysis.
Topics: Humans; Organoids; Extracellular Matrix; Bioengineering; Liver
PubMed: 35451330
DOI: 10.1089/ten.TEB.2021.0186 -
Dose-response : a Publication of... 2012Organisms are perpetually facing noxious insults but exhibit surprising diverse reaction patterns. Depending on the strength, frequency and quality of the stress stimuli...
Organisms are perpetually facing noxious insults but exhibit surprising diverse reaction patterns. Depending on the strength, frequency and quality of the stress stimuli biological systems may react with increased vitality, future stress resistance or with injury and degeneration. Whereas a multitude of such specific stress responses has been observed in diverse biological systems the underlying molecular mechanisms are mainly unknown. These knowledge restrictions urge the exploration of specific molecular signaling reactions controlling the ambivalent responses of cells and organisms to noxious effects. The adaptive responses of signaling networks to defined stress stimuli need to be investigated in a time-and dose-resolved manner in cellular and organismic models. Anticipated results are expected to significantly advance the understanding of the molecular signatures of stress responses and may also promote ongoing efforts for the effective use of the organism's preventive and regenerative potentials in modern medicine.
PubMed: 22423231
DOI: 10.2203/dose-response.11-012.Wetzker -
Biomedicines Jan 2021Regeneration is defined as the ability to regrow an organ or a tissue destroyed by degeneration or injury. Many human degenerative diseases and pathologies, currently... (Review)
Review
Regeneration is defined as the ability to regrow an organ or a tissue destroyed by degeneration or injury. Many human degenerative diseases and pathologies, currently incurable, could be cured if functional tissues or cells could be restored. Unfortunately, humans and more generally mammals have limited regenerative capabilities, capacities that are even further declining with age, contrary to simpler organisms. Initially thought to be lost during evolution, several studies have revealed that regenerative mechanisms are still present in mammals but are latent and thus they could be stimulated. To do so there is a pressing need to identify the fundamental mechanisms of regeneration in species able to efficiently regenerate. Thanks to its ability to regenerate most of its organs and tissues, the zebrafish has become a powerful model organism in regenerative biology and has recently engendered a number of studies attesting the validity of awakening the regenerative potential in mammals. In this review we highlight studies, particularly in the liver, pancreas, retina, heart, brain and spinal cord, which have identified conserved regenerative molecular events that proved to be beneficial to restore murine and even human cells and which helped clarify the real clinical translation potential of zebrafish research to mammals.
PubMed: 33445518
DOI: 10.3390/biomedicines9010065 -
Open Biology Jun 2018Multisensory integration is a mechanism that allows organisms to simultaneously sense and understand external stimuli from different modalities. These distinct signals... (Review)
Review
Multisensory integration is a mechanism that allows organisms to simultaneously sense and understand external stimuli from different modalities. These distinct signals are transduced into neuronal signals that converge into decision-making neuronal entities. Such decision-making centres receive information through neuromodulators regarding the organism's physiological state and accordingly trigger behavioural responses. Despite the importance of multisensory integration for efficient functioning of the nervous system, and also the implication of dysfunctional multisensory integration in the aetiology of neuropsychiatric disease, little is known about the relative molecular mechanisms. is an appropriate model system to study such mechanisms and elucidate the molecular ways through which organisms understand external environments in an accurate and coherent fashion.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Mechanotransduction, Cellular; Models, Biological; Neuromuscular Junction; Sensory Receptor Cells
PubMed: 29925633
DOI: 10.1098/rsob.180049