Altex-Alternatives To Animal Experimentation最新文献

Currently, the OECD has adopted three defined approaches (DAs) for eye hazard identification of non-surfactant liquids and solids (TG 467) according to the three UN GHS categories. We are now expanding the applicability domain with a new DA for chemicals having surfactant properties (DASF). It is based on a combination of recombinant human cornea-like epithelium test methods (TG 492: EpiOcular™ EIT or SkinEthic™ HCE EIT) and a modification of the Short Time Exposure (TG 491) method. The aim of the current study was to compare the performance of the DASF with the performance of other NAMs currently included in the OECD TGs and with the classification based on the Draize eye test to identify potential additional DAs. The minimum performance criteria (75% Cat. 1, 50% Cat. 2, 70% No Cat.) used for the adoption of the DAs currently included in TG 467 were used for this purpose. The DASF identified 90.9% of Cat. 1 (N = 23), 77.8% of Cat. 2 (N = 9), and 76.0% of No Cat. (N = 17) surfactants, meeting the minimum performance criteria. Some of the NAMs that are currently included in the TGs seem promising methods to become part of a DA to identify Cat. 1 or No Cat. for eye hazard assessment of surfactants. However, the number of surfactants that have been tested to evaluate their reliability and relevance was often too low. To date, the DASF is the only DA that has evaluated a sufficiently large number of surfactants and whose performance meets the minimum performance criteria.

AcutoX is a human in vitro test method for the evaluation of acute oral toxicity developed using a library of 67 curated test chemicals. These chemicals cover a wide variety of chemistries, indus­trial sectors, rodent toxicities, and all EPA and GHS hazard categories. The test uses two different cytotoxicity endpoints (neutral red uptake and MTT metabolism), performed both in the presence and absence of pooled human liver extract (S9), to produce four EC50 values. The EC50 values are used in prediction models to assign a “highly toxic” and “low toxicity” category for both EPA and GHS classification, which can be further refined to assign a hazard category. The binary “highly toxic” / “low toxicity” prediction model has an accuracy of 73.8% and 63.1% for EPA and GHS, respectively, with the subsequent hazard categorization offering a protective prediction (correct or higher category) in 90.0% and 93.3% of cases, respectively. Moreover, the AcutoX test can identify chemicals activated or detoxified by liver metabolism.

The regular t4 workshops on biology-inspired microphysiological systems (MPS) have become a reliable benchmark for assessing fundamental scientific, industrial, and regulatory trends in the MPS field. The 2023 workshop participants concluded that MPS technology as used in academia has matured significantly, as evidenced by the steadily increasing number of high-quality research publications, but that broad industrial adoption of MPS has been slow. Academic research using MPS is primarily aimed at accurately recapitulating human biology in MPS-based organ models to enable breakthrough discoveries. Examples of these developments are summarized in the report. In addition, we focus on key challenges identified during the previous workshop. Bridging gaps between academia, regulators, and industry is addressed. We also comment on overcoming bar­riers to trust and acceptance of MPS-derived data – the latter being particularly important in a regulatory environment. The status of implementation of the recommendations detailed in the 2020 report was reviewed. It is concluded that communication between stakeholders has improved signif­icantly, while the recommendations related to regulatory acceptance still need to be implemented. Participants noted that the remaining challenges for increased translation of these technologies into industrial use and regulatory decision-making will require further efforts on well-defined context of use qualifications, together with increased standardization. This will make MPS data more reliable and ultimately make these novel tools more economically sustainable. The long-term roadmap from the 2015 workshop was critically reviewed and updated. Recommendations for the next period and an outlook conclude the report.

On occasion of the DNT5 meeting in Konstanz, Germany (April 2024), participants brainstormed on future challenges concerning a regulatory implementation of the developmental neurotoxicity (DNT) in vitro test battery (DNT-IVB). The five discussion topics below outline some of the key issues, opportunities, and research directions for the next several years: (1) How to contextualize DNT hazard with information on potential maternal toxicity or other toxicity domains (non-DNT)? Several approaches on how to use cytotoxicity data from new approach methodologies (NAMs) were dis­cussed. (2) What opportunities exist for an immediate or near-future application of the DNT-IVB, e.g., as a prioritization step or add-on to other information? Initial examples are already emerging; the data can be used even if the battery is not converted to a defined approach. (3) How to establish data interpretation procedures for multi-dimensional endpoints that reduce dimensionality and are suitable for classification? A decision framework is required on how to use the DNT-IVB in a regu­latory context. Machine learning may provide novel classification models. (4) How can a battery of molecular initiating events (MIEs) be smartly linked to the DNT-IVB? At what tier of an overall strategy would MIEs be evaluated, and how would one optimally balance cost vs information yield. (5) What is the way forward to scientific validation of DNT NAMs and the DNT-IVB? A large set of animal data would be required for conventional approaches, while mechanistic information may establish relevance in other ways.

Hormone signaling plays an essential role during fetal life and is vital for brain development. Endo­crine-disrupting chemicals can interfere with the hormonal milieu during this critical time-period, disrupting key neurodevelopmental processes. Hence, there is a need for the development of assays that evaluate developmental neurotoxicity (DNT) induced by an endocrine mode of action. Herein, we evaluated the neural progenitor C17.2 cell line as an in vitro test system to aid in the detection of endocrine disruption-induced DNT. For this, C17.2 cells were exposed during 10 days of dif­ferentiation to agonists and antagonists of the thyroid hormone (THR), glucocorticoid (GR), retinoic acid (RAR), retinoic x (RXR), oxysterol (LXR), estrogen (ER), androgen (AR), and peroxisome prolif­erator activated delta (PPARβ/δ) receptors, as well as to the agonist of the vitamin D (VDR) receptor. Upon exposure and differentiation, neuronal morphology (neurite outgrowth and branching) and the percentage of neurons in culture were assessed by immunofluorescence. For this, the cells were stained for βIII-tubulin (neuronal marker). C17.2 cells decreased neurite outgrowth and branching in response to RAR, RXR and PPARβ/δ agonists. Exposure to the GR agonist increased the number of cells differentiating into neurons, while exposure to the RXR agonist had the opposite effect. With this approach, we demonstrate that C17.2 cells are responsive to GR, RAR, RXR, and PPARβ/δ agonists and hence could be useful to develop a test system for hazard assessment of endocrine disruption-induced DNT.

Microphysiological systems (MPS) are complex in vitro tools that incorporate cells derived from various healthy or disease-state human or animal tissues and organs. While MPS have limitations, including a lack of globally harmonized guidelines for standardization, they have already proven impactful in certain areas of drug development. Further research and regulatory acceptance of MPS will contribute to making them even more effective tools in the future. This review explores the potential applications of human liver, gut, lung, and cardiac MPS in drug development, focusing on disease modeling, safety assessment, and pharmacokinetic studies. Various technical param­eters and relevant endpoints for system assessment are discussed alongside challenges such as cell sourcing, reproducibility, and the integration of multiple tissues or organs. The importance of col­laborative efforts between academia, industry, and regulatory agencies to develop standardized protocols and validation criteria is emphasized. With ongoing advancements and cooperative ini­tiatives, MPS are poised to play a significant role in enhancing the predictivity and reliability of nonclinical testing, thereby transforming drug development and regulatory processes.

At present, quality control of diphtheria vaccines by both manufacturers and national control laboratories relies heavily on in vivo assays to confirm potency. As part of the VAC2VAC project we have developed a monoclonal antibody (mAb) enzyme-linked immunosorbent assay (ELISA) to measure the relative amount and quality of diphtheria toxoid (DTxd) in diphtheria-tetanus based vaccines and believe this test has the potential to play a key role in a control strategy no longer including an in vivo potency test. The mAb ELISA is highly specific, has good dilutional linearity, and is suitable for detecting DTxd in a range of different human vaccine products. We demonstrate the ability of the assay to discriminate between batches of different content and quality using vaccine batches that were prepared to contain differing amounts of DTxd or were altered by exposure to heat or oxidative stress. We also demonstrate successful transfer of the method to other laboratories and show that different diphtheria antigen materials may be able to serve as a reference antigen for local standardization of the method. The assay is ideally suited for incorporation into a consistency approach for routine diphtheria vaccine quality control testing and may be suitable to serve as the stability indicating test in replacement of the current in vivo potency test.