Atla-Alternatives To Laboratory Animals最新文献

Angiogenesis is an essential part of bone regeneration, as neovascularisation supports the supply of necessary oxygen, nutrients, and cellular transport. Bioactive glasses (BGs) have shown promise in enhancing both angiogenesis and bone regeneration. For the evaluation of the angiogenic potential of BGs, the chorioallantoic membrane (CAM) assay constitutes an attractive experimental model and has already gained increasing attention in BG-focused research. However, there is conflicting evidence as to whether the addition of cells, such as bone-marrow-derived mesenchymal stromal cells (BMSCs) to the CAM is necessary to facilitate the evaluation of the angiogenic potency of BGs. Therefore, in this study, the angiogenic potential of mesoporous bioactive glass nanoparticles (MBGNs; molar composition = 70% silica (SiO₂) and 30% calcium oxide (CaO)) was assessed by using the in ovo CAM assay, both in the presence and the absence of exogenous BMSCs. Compared to the BMSC-free and MBGN-free control groups, both BMSCs alone and MBGNs without the addition of BMSCs were able to induce an equally strong, significantly enhanced angiogenic response on the CAM. The combination of MBGNs with BMSCs did not yield a more pronounced angiogenic response, as compared to MBGNs without the addition of cells. Thus, MBGNs exhibit a strong intrinsic angiogenic potential that is not dependent on the presence of exogenous BMSCs. Therefore, the CAM assay without added cells can be used as a simplified, reproducible and cost-effective method for accurate preclinical testing of the angiogenic potential of BGs.

Recent advances in neural differentiation have unveiled new possibilities that could potentially be applied to the development of human-relevant non-animal models, for use in fields such as biomedical research and drug screening. Thus, the directed differentiation of tissue stem cells toward neural progenitor cells or neural stem cells, by small molecules and growth factors without the need for genetic manipulation, has attracted great attention. The in vitro generation of neural progenitor cells, and their proliferation and lineage commitment are regulated by signaling pathways activated by small molecules and growth factor families, including various fibroblast growth factors (FGFs). FGF-9 regulates the differentiation of neural stem cells, not only during embryonic development, but also contributes to adult neurogenesis and the protection of degenerating neurons. Here, we investigate an improved protocol for neural stem cell proliferation, differentiation and lineage commitment of adipose tissue-derived mesenchymal stem cells (AD-MSCs). We evaluated a cocktail of valproic acid (VPA), CHIR99021 and FGF-9, both alone and in combination, for the potential to induce cell differentiation. The AD-MSCs were isolated from human omentum fat and characterised immunologically by the presence of specific mesenchymal markers and multi-lineage differentiation potential. To assess the potential toxic effect of each cocktail, cell proliferation and viability were determined, followed by confirmation of neural differentiation via quantitative reverse transcriptase real-time PCR (qRT-PCR) and immunocytochemistry. The combined administration of VPA and FGF-9 promoted neurogenesis and neuronal fate commitment of AD-MSCs cultures, leading to significantly increased expression of the neural stem cell markers Nestin and Sox-2, as well as the neuronal cell marker MAP-2. This study contributes to our understanding of the role of FGF-9 in neural differentiation from human AD-MSCs. Our simplified protocol uses VPA and FGF-9 to efficiently generate neural progenitor cells, avoiding complex and prolonged induction methods, making it ideal for use in, for example, in vitro human-relevant drug screening for neurotoxicity.

Antibodies are indispensable tools in biomedical research, yet the widespread use of animal-derived antibodies contributes to poor reproducibility and raises serious ethical concerns. Many commercial antibodies fail to bind their intended targets, leading to irreproducible results, wasted resources and stalled progress. In Europe alone, over a million animals are used annually for antibody production. Non-animal-derived recombinant antibodies and antibody mimetics offer a scalable, scientifically valid alternative. Endorsed by the European Union Reference Laboratory for alternatives to animal testing (EURL ECVAM), these reagents deliver greater consistency, transparency and ethical alignment. Despite their advantages, they are currently estimated to make up less than 5% of research reagents, held back by limited awareness, access barriers and persistent misconceptions about performance. To address these challenges, the Centre for Human Specific Research developed the open-access Recombinant Antibodies & Mimetics Database. This platform links researchers to ethically sourced, sequence-defined affinity reagents and features a unique colour-coded classification system to clearly indicate the extent of animal involvement. By improving transparency, the database empowers informed decision-making and supports alignment with best practices. More than a sourcing tool, the platform drives advocacy for systemic change, encouraging funders, institutions, publishers and regulators to prioritise recombinant antibodies and antibody mimetics. Its ultimate aim is to make high-quality animal-free recombinant and mimetic antibodies the global standard, supporting a more reproducible, ethical and forward-looking future for antibody science.

Assays to predict the skin sensitisation potential of substances commonly address the molecular initiating event (MIE) of the adverse outcome pathway (AOP), which is the covalent binding of chemicals to proteins. This represents the first key event in the pathway. In chemico approaches have emerged as validated alternatives to conventional animal testing methods to determine this process. This review explores the integration of biosensor-based approaches to supplement other in chemico methods, for use as alternatives to the 'gold standard' Local Lymph Node Assay (LLNA) in skin sensitisation testing. While surface plasmon resonance-based biosensors have shown promise, they exhibit limitations such as poor sensitivity. To overcome such limitations, this review highlights the use of impedance-based biosensors in the study of hapten-skin protein interactions, which are associated with the MIE in skin sensitisation. Impedance-based biosensors have exhibited impressive performance, with a specificity of 97%, a sensitivity of 83% and an accuracy of 92% being obtained in one study (N = 49 substances). The advantages of impedance-based biosensors include label-free methodologies, high sensitivity, low cost and operational simplicity. This review also covers recent advancements in the use of biosensors in cosmetic studies and skin research, as well as comparisons of the limitations of the various in chemico methods and future perspectives for skin sensitisation assessment. The use of impedance-based biosensors as part of integrated testing approaches alongside other in chemico testing methods, can represent a reliable approach for skin sensitisation assessment, while supporting the reduction and replacement of animal use in toxicity testing.

For centuries, animals have been used in research due to their genetic and physiological similarities to humans. However, significant differences exist between humans and animals, which have the potential to confound results obtained from such experiments. These differences result in reduced translatability of animal data to humans, which is a major contributing factor to the 92% failure rate for novel therapies in clinical trials. Advances in scientific research have enabled the development of human-focused New Approach Methodologies (NAMs), which include in silico and 3-D in vitro models. By harnessing these novel approaches, greater predictive power for human biology, human diseases and assessment of novel therapies could be achieved. However, several obstacles remain to their wider adoption, including potential financial constraints, publication bias, and some concerns about the reliability of NAMs due to the novelty of this field, compared to animal studies. Here, we outline the differences between humans and animals used in research, discuss in detail the obstacles to the greater adoption of NAMs in research, and provide recommendations on how to accelerate a shift toward human-focused research.

Uropathogenic Escherichia coli (UPEC) is responsible for the majority of urinary tract infections, including those in catheterised patients. Galleria mellonella, an insect species, has been proposed as an alternative in vivo model to study the pathogenicity of E. coli. The aim of this study was to determine the pathogenicity of 48 UPEC strains using the larval disease score obtained from G. mellonella larvae model. The bacteria were also classified according to their phylogenetic group and the ability to form biofilms. The larvae were inoculated with the bacteria and observed for 72 hours. The LD₅₀, mortality rate, and survival curve for each UPEC strain were assessed. A larval disease score (0-10) was determined, which considered mortality, larval activity, cocoon formation and melanisation. Phylogenetic groups were determined by using PCR, and biofilm formation was assessed by using the crystal violet assay. The larval disease score permitted the classification of the bacteria into three pathogenicity groups (low, intermediate and high). Bacteria were classified into six of the seven phylogenetic groups tested (i.e. A, B1, B2, C, D and F), but none were classified into group E. Biofilm-producing strains were detected at both incubation times used. There was no significant association between the larval disease score and the phylogenetic group. The larvae were susceptible to infection by all UPEC strains and the larval disease score deserves attention as a potential means of assessing the pathogenicity of UPEC isolates.