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In vitro human tissues via multi-material 3-D bioprinting

David B. Kolesky, Kimberly A. Homan, Mark Skylar-Scott and Jennifer A. Lewis

This paper highlights the foundational research on multi-material 3-D bioprinting of human tissues, for which the Lewis Bioprinting team at Harvard University was awarded the 2017 Lush Science Prize. The team’s bioprinting platform enables the rapid fabrication of 3-D human tissues that contain all of the essential components found in their in vivo counterparts: cells, vasculature (or other tubular features) and extracellular matrix. The printed 3-D tissues are housed within a customised perfusion system and are subjected to controlled microphysiological environments over long durations (days to months). As exemplars, the team created a thick, stem cell-laden vascularised tissue that was controllably differentiated toward an osteogenic lineage in situ, and a 3-D kidney tissue that recapitulated the proximal tubule, a subunit of the nephron responsible for solute reabsorption. This highly versatile platform for manufacturing 3-D human tissue in vitro opens new avenues for replacing animal models used to develop next-generation therapies, test toxicity and study disease pathology.
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The Safe and Ethical Supply of Human Tissues for In Vitro Studies

Robert Andersona

Medical and scientific research workers in industry, academia and hospitals need human tissue samples for their research programmes. Many bioscientists have tried to achieve this by establishing a direct relationship with a surgeon or a pathologist at a local hospital. In many cases, the supply is unreliable and, consequently, the progress of good research has been frustrated.1 The recent controversy involving staff working at the Alder Hey and Bristol Hospitals has shown that the consent of the next of kin to use non-transplantable organs and tissues for medical research has not always been obtained. It is highly likely that this practice has occurred at other hospitals throughout the UK.
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2017-01-09T06:27:09+00:00 Tags: |

Could Fresh Human Tissues Play a Key Role in Drug Development?

Chris Hillier and David Bunton

Biopta was founded in 2002, to provide human tissue-based drug development and testing services to the pharmaceutical industry. Although animal tissues are readily available and are relatively inexpensive, they frequently fail to faithfully predict the results seen in the clinic. Human tissues can provide integrated responses to test drugs in a manner more representative than individual cell types or cell lines alone, and more-directly relevant to the species of interest — Homo sapiens. In order to expand the use of human tissues, however, an improved infrastructure for the collection and distribution of fresh, functional tissues is highly desirable. Moreover, where there is the potential to obtain tissue from various locations, it becomes possible to test tissue that is specific to the site of drug activity. This is important, as differences may occur between the same tissue types in different locations in the body. The detection of adverse effects is greatly helped by knowledge of how existing drugs behave in the human body. These drugs can act as reference compounds, so that new compounds can then be compared, by using standard concentration– response type studies, in a huge variety of tissues, and their effects extrapolated from what is known of the reference compounds.
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Artificial Human Tissues from Cord and Cord Blood Stem Cells for Multi-organ Regenerative Medicine: Viable Alternatives to Animal In Vitro Toxicology

Marcin Jurga, Nico Forraz and Colin P. McGuckin

New medicinal products and procedures must meet very strict safety criteria before being applied for use in humans. The laboratory procedures involved require the use of large numbers of animals each year. Furthermore, such investigations do not always give an accurate translation to the human setting.
Here, we propose a viable alternative to animal testing, which uses novel technology featuring human cord and cord blood stem cells. With over 130 million children born each year, cord and cord blood remains the most widely available alternative to the use of animals or cadaveric human tissues for in vitro toxicology.
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The Use of Human Tissues and Cells in Biomedical Research: The Unusual Suspects

Andrew Bennett

There are compelling reasons to search for alternatives to the use of animals in medical and pharmaceutical research. Aside from the obvious animal welfare issues, both the well-established differences between animal models and humans, and the inherent inter-individual variability in human biological responses, indicate that human-based alternatives are urgently required. However, any such alternative must out-perform the animal-based alternative, otherwise there will be little or no uptake and adoption by end-users. Data obtained from inbred animal models is often highly reproducible, and is therefore attractive to researchers in the fields of biomedical and pharmaceutical research. The inter-individual variability observed during human volunteer and human tissue-based studies is often considered to be problematic, and has been highlighted further with the advent of the ‘omics’ technologies, which generate large biological datasets. However, the variability in both baseline data and response to pharmacological or toxicological challenge observed in human tissues potentially contains a veritable gold mine of information, which may be critical for the advancement of drug discovery.
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The Use of Functional Human Tissues in Drug Development

David Bunton

Drug development currently depends on animal models to provide an accurate prediction of human physiology and pathophysiology. However, as is clear from clinical trial failures during phases II and III, such in vivo models do not always predict the effects that a drug can elicit in humans. Tests with human tissues, which are obviously considered to be the closest model of human in vivo function, could fill the gap between animal-based tests and trials in patients. Despite clear advantages, logistical and ethical barriers prevent fresh human tissues from being widely used during drug development. Biopta is aiming to make human tissue testing a regular element of drug development, and works to lower the barriers surrounding the availability of tissue and practicalities of experimental work.
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Development and Application of Human Virtual Excitable Tissues and Organs: From Premature Birth to Sudden Cardiac Death

Arun V. Holden

The electrical activity of cardiac and uterine tissues has been reconstructed by detailed computer models in the form of virtual tissues. Virtual tissues are biophysically and anatomically detailed, and represent quantitatively predictive models of the physiological and pathophysiological behaviours of tissue within an isolated organ. The cell excitation properties are quantitatively reproduced by equations that describe the kinetics of a few dozen proteins. These equations are derived from experimental measurements of membrane potentials, ionic currents, fluxes, and concentrations. Some of the measurements were taken from human cells and human ion channel proteins expressed in non-human cells, but they were mostly taken from cells of other animal species. Data on tissue geometry and architecture are obtained from the diffusion tensor magnetic resonance imaging of ex vivo or post mortem tissue, and are used to compute the spread of current in the tissue. Cardiac virtual tissues are well established and reproduce normal and pathological patterns of cardiac excitation within the atria or ventricles of the human heart. They have been applied to increase the understanding of normal cardiac electrophysiology, to evaluate the candidate mechanisms for re-entrant arrhythmias that lead to sudden cardiac death, and to predict the tissue level effects of mutant or pharmacologically-modified ion channels. The human full-term virtual uterus is still in development. This virtual tissue reproduces the in vitro behaviour of uterine tissue biopsies, and provides possible mechanisms for premature labour.
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Establishment of a Tumour–Stroma Airway Model (OncoCilAir) to Accelerate the Development of Human Therapies Against Lung Cancer

Christophe Mas, Bernadett Boda, Mireille Caul Futy, Song Huang, Ludovic Wisniewski and Samuel Constant

This paper highlights the work for which OncoTheis, a Swiss biotechnology company, engaged in the development of innovative bioengineered tissues and organoids for cancer research, was co-awarded the 2015 Lush Science Prize. Noting that the use of animal models failed to lead to the design of effective treatments for cancer, OncoTheis has opted to develop in vitro models based exclusively on human cells. The company currently focuses on lung cancer, which is the leading cause of cancer-related deaths worldwide, with more than one million deaths per year. To address this public health concern, we developed OncoCilAir™, a new 3-D model that mimics in vitro the progression of the disease as it happens in patients. In this system, bronchial and lung tumour cells obtained from discarded surgical tissue are cocultured in a Petri dish to reconstitute a fragment of the human lung. After appropriate differentiation, the culture closely reproduces malignant pulmonary nodules invading a small piece of functional airway tissue. As OncoCilAir includes both healthy and cancerous tissues, it can be used to test tumour-killing activity and the adverse effects of chemotherapies and other anti-cancer drugs. Moreover, a single culture can be maintained for up to three months, which permits studies of longer-term effects, including the assessment of drug resistance and tumour recurrence. OncoCilAir heralds a new generation of integrated in vitro models, which is expected to increase the quality of preclinical research while replacing animal testing.
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Better Science with Human Cell-based Organ and Tissue Models

Tuula Heinonen

At present, animal-based models are the major test systems for assessing the tolerability and safety of chemical substances for regulatory purposes, and also for pivotal efficacy testing in pharmaceutical development. In spite of the high genetic similarity between many laboratory animals and humans, animal models are very poor predictors of human health effects and pathophysiological processes. Thus, models and testing strategies that are more relevant to human biology, are needed for these purposes. The best predictability is achieved with human organotypic models that mimic the microenvironment of human tissues. During their development, such models have to be characterised at the structural, genetic and functional levels, and compared to the respective human tissues. Their predictivity should be confirmed by using known reference chemicals with corresponding human data. The use of these methods in safety assessment and biomedical research, combined with the knowledge gained of the underlying biological processes on gene and protein expression, as well as on cellular signalling, will ultimately lead to better human science and animal welfare.
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A Method for the In Vitro Exposure of Human Cells to Environmental and Complex Gaseous Mixtures: Application to Various Types of Atmosphere

Michaela Aufderheide, Jan W. Knebel and Detlef Ritter

The application of in vitro methods to the analysis of the effects of airborne materials is still limited, because there are no generally accepted concepts and technologies for efficiently exposing adherent growing cells to test atmospheres, especially those comprising complex mixtures of gaseous and particulate phases. The introduction of in vitro research into the field of inhalation toxicology offers a unique possibility for using human cells and tissues for pre-screening studies, thus reducing the necessity for animal experiments, and cutting the numbers of animals used in toxicological testing. We therefore developed a novel experimental concept that uses an exposure device based on the cell cultivation system CULTEX (Patent No. DE 198011763; PCT/EP99/00295). This allowed us to investigate environmental atmospheres, which were chemically and physically unmodified, in an in vitro system, by exposing the target cells directly at the air/liquid interface. The exposure device itself is small and flexible enough to be connected to a variety of aerosol-generating systems without the need for an incubator, as it fulfils all the requirements for maintaining cell viability over a defined period. The general applicability and the sensitivity of this in vitro approach for testing various generated atmospheres under the same cell-exposure conditions were demonstrated by studying dose-dependent cytotoxic effects in human lung epithelial cells exposed to air contaminated with single gases or complex mixtures, such as diesel exhaust fumes and side-stream cigarette smoke.
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