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Multipotent self-renewing haematopoietic stem cells (HSCs) regenerate the adult blood system after transplantation 1 , which is a curative therapy for numerous diseases including immunodeficiencies and leukaemias 2 . Although substantial effort has been applied to identifying HSC maintenance factors through the characterization of the in vivo bone-marrow HSC microenvironment or niche 3 – 5 , stable ex vivo HSC expansion has previously been unattainable 6 , 7 . Here we describe the development of a defined, albumin-free culture system that supports the long-term ex vivo expansion of functional mouse HSCs. We used a systematic optimization approach, and found that high levels of thrombopoietin synergize with low levels of stem-cell factor and fibronectin to sustain HSC self-renewal. Serum albumin has long been recognized as a major source of biological contaminants in HSC cultures 8 ; we identify polyvinyl alcohol as a functionally superior replacement for serum albumin that is compatible with good manufacturing practice. These conditions afford between 236- and 899-fold expansions of functional HSCs over 1 month, although analysis of clonally derived cultures suggests that there is considerable heterogeneity in the self-renewal capacity of HSCs ex vivo. Using this system, HSC cultures that are derived from only 50 cells robustly engraft in recipient mice without the normal requirement for toxic pre-conditioning (for example, radiation), which may be relevant for HSC transplantation in humans. These findings therefore have important implications for both basic HSC research and clinical haematology. An albumin-free culture system for the long-term ex vivo expansion of mouse haematopoietic stem cells produces 236- to 899-fold expansion, and generates cultures that robustly engraft in recipient mice without toxic pre-conditioning.

Limited access to embryos has hampered the study of human embryogenesis and disorders that occur during early pregnancy. Human pluripotent stem cells provide an alternative means to study human development in a dish 1 – 7 . Recent advances in partial embryo models derived from human pluripotent stem cells have enabled human development to be examined at early post-implantation stages 8 – 14 . However, models of the pre-implantation human blastocyst are lacking. Starting from naive human pluripotent stem cells, here we developed an effective three-dimensional culture strategy with successive lineage differentiation and self-organization to generate blastocyst-like structures in vitro. These structures—which we term ‘human blastoids’—resemble human blastocysts in terms of their morphology, size, cell number, and composition and allocation of different cell lineages. Single-cell RNA-sequencing analyses also reveal the transcriptomic similarity of blastoids to blastocysts. Human blastoids are amenable to embryonic and extra-embryonic stem cell derivation and can further develop into peri-implantation embryo-like structures in vitro. Using chemical perturbations, we show that specific isozymes of protein kinase C have a critical function in the formation of the blastoid cavity. Human blastoids provide a readily accessible, scalable, versatile and perturbable alternative to blastocysts for studying early human development, understanding early pregnancy loss and gaining insights into early developmental defects. An in vitro culture strategy enables the generation of blastocyst-like structures termed human blastoids from naive human pluripotent stem cells, providing a model for studying human embryogenesis.

The production of drugs, cosmetics, and food which are derived from plant cell and tissue cultures has a long tradition. The emerging trend of manufacturing cosmetics and food products in a natural and sustainable manner has brought a new wave in plant cell culture technology over the past 10 years. More than 50 products based on extracts from plant cell cultures have made their way into the cosmetics industry during this time, whereby the majority is produced with plant cell suspension cultures. In addition, the first plant cell culture-based food supplement ingredients, such as Echigena Plus and Teoside 10, are now produced at production scale. In this mini review, we discuss the reasons for and the characteristics as well as the challenges of plant cell culture-based productions for the cosmetics and food industries. It focuses on the current state of the art in this field. In addition, two examples of the latest developments in plant cell culture-based food production are presented, that is, superfood which boosts health and food that can be produced in the lab or at home.

Embryonic stem cells (ESCs) are derived from the inner cell mass of preimplantation blastocysts. From agricultural and biomedical perspectives, the derivation of stable ESCs from domestic ungulates is important for genomic testing and selection, genome engineering, and modeling human diseases. Cattle are one of the most important domestic ungulates that are commonly used for food and bioreactors. To date, however, it remains a challenge to produce stable pluripotent bovine ESC lines. Employing a culture system containing fibroblast growth factor 2 and an inhibitor of the canonical Wnt-signaling pathway, we derived pluripotent bovine ESCs (bESCs) with stable morphology, transcriptome, karyotype, population-doubling time, pluripotency marker gene expression, and epigenetic features. Under this condition bESC lines were efficiently derived (100% in optimal conditions), were established quickly (3–4 wk), and were simple to propagate (by trypsin treatment). When used as donors for nuclear transfer, bESCs produced normal blastocyst rates, thereby opening the possibility for genomic selection, genome editing, and production of cattle with high genetic value.

Three-dimensional (3D) cell cultures have emerged as valuable tools in cancer research, offering significant advantages over traditional two-dimensional (2D) cell culture systems. In 3D cell cultures, cancer cells are grown in an environment that more closely mimics the 3D architecture and complexity of in vivo tumors. This approach has revolutionized cancer research by providing a more accurate representation of the tumor microenvironment (TME) and enabling the study of tumor behavior and response to therapies in a more physiologically relevant context. One of the key benefits of 3D cell culture in cancer research is the ability to recapitulate the complex interactions between cancer cells and their surrounding stroma. Tumors consist not only of cancer cells but also various other cell types, including stromal cells, immune cells, and blood vessels. These models bridge traditional 2D cell cultures and animal models, offering a cost-effective, scalable, and ethical alternative for preclinical research. As the field advances, 3D cell cultures are poised to play a pivotal role in understanding cancer biology and accelerating the development of effective anticancer therapies. This review article highlights the key advantages of 3D cell cultures, progress in the most common scaffold-based culturing techniques, pertinent literature on their applications in cancer research, and the ongoing challenges. Graphical Abstract

Haematopoietic stem cells (HSCs) are a rare cell type that reconstitute the entire blood and immune systems after transplantation and can be used as a curative cell therapy for a variety of haematological diseases 1 , 2 . However, the low number of HSCs in the body makes both biological analyses and clinical application difficult, and the limited extent to which human HSCs can be expanded ex vivo remains a substantial barrier to the wider and safer therapeutic use of HSC transplantation 3 . Although various reagents have been tested in attempts to stimulate the expansion of human HSCs, cytokines have long been thought to be essential for supporting HSCs ex vivo 4 . Here we report the establishment of a culture system that allows the long-term ex vivo expansion of human HSCs, achieved through the complete replacement of exogenous cytokines and albumin with chemical agonists and a caprolactam-based polymer. A phosphoinositide 3-kinase activator, in combination with a thrombopoietin-receptor agonist and the pyrimidoindole derivative UM171, were sufficient to stimulate the expansion of umbilical cord blood HSCs that are capable of serial engraftment in xenotransplantation assays. Ex vivo HSC expansion was further supported by split-clone transplantation assays and single-cell RNA-sequencing analysis. Our chemically defined expansion culture system will help to advance clinical HSC therapies. A culture system allows the long-term expansion of human haematopoietic stem cells (HSCs) in vivo without the use of recombinant cytokines or albumin, with potential applications for clinical therapies involving HSCs.

3D cell culture has emerged as a relevant and promising alternative model for improving the preclinical phase of pharmaceutical development. It mimics cell-cell and cell-matrix interactions, as well as drug penetration and toxicity responses. However, there are currently no standardized methods that could lead to highly predictive treatment responses. In this context, the focus of this study was the adaptation of a liquid overlay technique, to generate a large and reproducible panel of six spheroid models, including melanoma, small cell lung cancer, non-small cell lung cancer, ovarian cancer, non-tumorigenic breast tissue and healthy kidney tissue. In this way, four cell concentrations (200 to 10,000 cells per well) with four matrix percentages (0 to 3%) were tested to determine the optimal combination based on their compaction, proliferation and viability. The surface characterization of each model was then assessed using scanning electron microscopy. Afterwards, the cytostatic and cytotoxic responses of these models to three targeted anti-PARP therapies, Olaparib, Rucaparib and Niraparib, were analyzed, revealing their sensitivity. These results demonstrated that our liquid overlay-based technique provides both a large cell culture panel, whatever the tissue type or pathological level, and an automated drug screening process that could lead to highly predictive efficacy results.

Our understanding of how human embryos develop before gastrulation, including spatial self-organization and cell type ontogeny, remains limited by available two-dimensional technological platforms 1 , 2 that do not recapitulate the in vivo conditions 3 – 5 . Here we report a three-dimensional (3D) blastocyst-culture system that enables human blastocyst development up to the primitive streak anlage stage. These 3D embryos mimic developmental landmarks and 3D architectures in vivo, including the embryonic disc, amnion, basement membrane, primary and primate unique secondary yolk sac, formation of anterior–posterior polarity and primitive streak anlage. Using single-cell transcriptome profiling, we delineate ontology and regulatory networks that underlie the segregation of epiblast, primitive endoderm and trophoblast. Compared with epiblasts, the amniotic epithelium shows unique and characteristic phenotypes. After implantation, specific pathways and transcription factors trigger the differentiation of cytotrophoblasts, extravillous cytotrophoblasts and syncytiotrophoblasts. Epiblasts undergo a transition to pluripotency upon implantation, and the transcriptome of these cells is maintained until the generation of the primitive streak anlage. These developmental processes are driven by different pluripotency factors. Together, findings from our 3D-culture approach help to determine the molecular and morphogenetic developmental landscape that occurs during human embryogenesis. A 3D culture system to model human embryonic development, together with single-cell transcriptome profiling, provides insights into the molecular developmental landscape during human post-implantation embryogenesis.

In the 20 years since human embryonic stem cells, and subsequently induced pluripotent stem cells, were first described, it has become apparent that during long-term culture these cells (collectively referred to as ‘pluripotent stem cells’ (PSCs)) can acquire genetic changes, which commonly include gains or losses of particular chromosomal regions, or mutations in certain cancer-associated genes, especially TP53. Such changes raise concerns for the safety of PSC-derived cellular therapies for regenerative medicine. Although acquired genetic changes may not be present in a cell line at the start of a research programme, the low sensitivity of current detection methods means that mutations may be difficult to detect if they arise but are present in only a small proportion of the cells. In this Review, we discuss the types of mutations acquired by human PSCs and the mechanisms that lead to their accumulation. Recent work suggests that the underlying mutation rate in PSCs is low, although they also seem to be particularly susceptible to genomic damage. This apparent contradiction can be reconciled by the observations that, in contrast to somatic cells, PSCs are programmed to die in response to genomic damage, which may reflect the requirements of early embryogenesis. Thus, the common genetic variants that are observed are probably rare events that give the cells with a selective growth advantage.Cultured pluripotent stem cells (PSCs) acquire genetic changes — gains or losses of entire chromosomal regions, or point mutations, including in cancer-associated genes such as TP53. Recent work provides insights into the mechanisms of mutation and selection, which have implications for the use of human PSCs in regenerative medicine.

The adoption of three-dimensional (3D) cell culture systems represents a critical advancement in biomedical research, better mimicking complex 3D tissue environments than traditional two-dimensional (2D) models. However, variability in experimental outcomes has limited their reproducibility and clinical translation. Here, we systematically analyzed 32,000 spheroid images to identify key parameters influencing 3D model reliability. Our large-scale analysis revealed that oxygen levels significantly affect spheroid size and necrosis, while media composition (e.g., glucose and calcium concentrations) and serum levels (0–20%) critically regulate cell viability and structural integrity. For instance, spheroids cultured in 3% oxygen exhibited reduced dimensions and increased necrosis, whereas serum concentrations above 10% promoted dense spheroid formation with distinct necrotic and proliferative zones. By integrating single-cell RNA sequencing and automated image analysis, we uncovered dynamic gene expression patterns linked to spheroid maturation and hypoxia. These findings provide actionable guidelines for standardizing 3D culture protocols, addressing critical reproducibility challenges. Our work establishes a robust framework to enhance the reliability of 3D models in drug testing, personalized medicine, and tumor biology, facilitating their broader adoption in translational research.