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So far Rita Seabra has created 136 blog entries.

A Comparison of Scaffold-free and Scaffold-based Reconstructed Human Skin Models as Alternatives to Animal Use

Beste Kinikoglu

Tissue engineered full-thickness human skin substitutes have various applications in the clinic and in the laboratory, such as in the treatment of burns or deep skin defects, and as reconstructed human skin models in the safety testing of drugs and cosmetics and in the fundamental study of skin biology and pathology. So far, different approaches have been proposed for the generation of reconstructed skin, each with its own advantages and disadvantages. Here, the classic tissue engineering approach, based on cell-seeded
polymeric scaffolds, is compared with the less-studied cell self-assembly approach, where the cells are coaxed to synthesise their own extracellular matrix (ECM). The resulting full-thickness human skin substitutes were analysed by means of histological and immunohistochemical analyses. It was found that both the scaffold-free and the scaffold-based skin equivalents successfully mimicked the functionality and morphology of native skin, with complete epidermal differentiation (as determined by the expression of filaggrin), the presence of a continuous basement membrane expressing collagen VII, and new ECM deposition by dermal fibroblasts. On the other hand, the scaffold-free model had a thicker epidermis and a significantly higher number of Ki67-positive proliferative cells, indicating a higher capacity for self-renewal, as compared to the scaffold-based model.

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The Use of Gatekeeping Procedures in the Statistical Planning of Animal Experiments

Benjamin Mayer, Vicky Stahl and Martina Kron

Statistical sample size calculation is essential when planning animal experiments in basic medical research. Usually, such trials involve the testing of multiple hypotheses, and interpreting them in a confirmative manner would require the appropriate adjustment of the Type 1 error. This has to be taken into account as early as possible during sample size estimation — otherwise, all the results obtained would be
exploratory, i.e. without cogency. In this paper, the concept of gatekeeping is introduced, along with alternative approaches for Type 1 error adjustment. The application of gatekeeping to the calculation of sample size is demonstrated by using data sets from case studies. Overall, the evaluation of these examples showed that gatekeeping is able to keep the required number of animals comparatively small. In contrast to exploratory planning, which led to the lowest sample sizes, gatekeeping suggested a mean increase of 12% in sample size, while conservative Bonferroni adjustment raised the sample size by 34% on average. Gatekeeping is a prominent strategy for handling the multiple testing problem, and has been proven to keep the required sample sizes in animal studies comparatively low. Therefore, it is a suitable approach to a compromise between the Three Rs principle of reduction and the appropriate handling of the multiplicity issue in animal trials with a confirmative focus.

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Fetal Bovine Serum (FBS) — A Pain in the Dish?

Jan van der Valk and Gerhard Gstraunthaler

The use of Fetal Bovine Serum in replacement alternative methods is associated with serious animal welfare concerns, as well as worrying reproducibility issues

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Harmonisation of Animal Testing Alternatives in China

Shujun Cheng, Xiaoting Qu and Yao Qin

More and more countries are lining up to follow the EU’s approach and implement a full ban on the sale of cosmetics that have been tested on animals, which has been the case in the EU since 2013. Besides animal welfare considerations, the need for mutual acceptance of data (MAD) and harmonisation of the global market have made the move toward non-animal testing a desirable general trend for countries
worldwide. Over the last 10 years, the concept of alternative methods has been gradually developing in China. This has seen the harmonisation of relevant legislation, the organisation of various theoretical and hands-on training sessions, the exploration of method validation, the adoption of internationally recognised methods, the propagation of alternative testing standards, and an in-depth investigation into the potential use of in vitro methods in the biosciences. There are barriers to this progress, including the demand for a completely new infrastructure, the need to build technology capability, the requirement for a national standardisation system formed through international co-operation, and the lack of technical assistance to facilitate self-innovation. China is now increasing speed in harmonising its approach to the use of non-animal alternatives, accelerating technological development and attempting to incorporate
non-animal, in vitro, testing methods into the national regulatory system.

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2016 Lush Science Prize

Jenny McCann and Terry McCann

The Lush Prize supports animal-free testing by awarding monetary prizes totalling £250,000 to the most effective projects and individuals who have been working toward the goal of replacing animals in product or ingredient safety testing. Prizes are awarded for developments in five strategic areas: Science; Lobbying; Training; Public Awareness; and Young Researchers. In the event of a major breakthrough leading to the replacement of animal tests in the area of 21st Century Toxicology, a Black Box Prize (equivalent to the entire annual fund of £250,000) is awarded. The Science Prize is awarded to the researchers whose work the judging panel believe has made the most significant contribution to the replacement of animal testing in the preceding year. This Background Paper outlines the research projects that were shortlisted and presented to the judging panel as potential candidates for the 2016 Lush Science Prize. This process involved reviewing recent work of the relevant scientific institutions and projects in this area, such as the OECD, CAAT, The Hamner Institutes, ECVAM, UK NC3Rs, and the US Tox21 Programme. Recent developments in toxicity testing research were also identified by searching for relevant published papers in the literature, and analysing abstracts from conferences focusing on animal replacement in toxicity testing that had been held in the preceding 12 months — for example the EUSAAT-Linz, Society of Toxicology, and SEURAT-1 conferences.
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High-throughput Prediction of Nephrotoxicity in Humans

Lit-Hsin Loo and Daniele Zink

The Lush Science Prize 2016 was awarded to Daniele Zink and Lit-Hsin Loo for the interdisciplinary and collaborative work between their research groups in developing alternative methods for the prediction of nephrotoxicity in humans. The collaboration has led to the establishment of a series of pioneering alternative methods for nephrotoxicity prediction, which includes: predictive gene expression markers based on pro-inflammatory responses; predictive in vitro cellular models based on pluripotent stem cell-derived proximal tubular-like cells; and predictive cellular phenotypic markers based on chromatin and cytoskeletal changes. A high-throughput method was established for chemical testing, which is currently being used to predict the potential human nephrotoxicity of ToxCast compounds in collaboration with the US Environmental Protection Agency. Similar high-throughput imaging-based methodologies are currently being developed and adapted by the Zink and Loo groups, to include other human organs and cell types. The ultimate goal is to develop a portfolio of methods accepted for the accurate prediction of human organ-specific toxicity and the consequent replacement of animal experiments.
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New Animal-free Concepts and Test Methods for Developmental Toxicity and Peripheral Neurotoxicity

Marcel Leist

The complex toxicological fields of repeat dose organ toxicity (RDT) and developmental and reproductive toxicity (DART) still require new concepts and approaches to achieve a fully animal-free safety assessment of chemicals. One novel approach is the generation of relevant human cell types from pluripotent stem cells, and the use of such cells for the establishment of phenotypic test methods. Due to their broad endpoints, such tests capture multiple types of toxicants, i.e. they are a readout for the activation of many adverse outcome pathways (AOPs). The 2016 Lush Science Prize was awarded for the development of one such assay, the PeriTox test, which uses human peripheral neurons generated from stem cells. The assay endpoints measure various cell functions, and these give information on the potential neurotoxicity and developmental neurotoxicity hazard of test compounds. The PeriTox test method has a high predictivity and sensitivity for peripheral neurotoxicants, and thus addresses the inherent challenges in pesticide testing and drug development. Data from the test can be obtained quickly and at a relatively high-throughput, and thus, the assay has the potential to replace animal-based safety assessment during early product development or for screening potential environmental toxicants.
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