Organoids, Volume 4, Issue 1 (March 2025) – 2 articles

Peritoneal carcinomatosis from gastrointestinal tumours is considered a poor prognostic factor, with a median overall survival of six to nine months in the absence of intervention. The advent of patient-derived organoid cultures (PDOs) has provided a breakthrough in personalised medicine, allowing researchers and clinicians to model the complexity and heterogeneity of individual tumours in vitro. PDOs hold great promise in this field, as variations in the management of peritoneal carcinomatosis due to differences in the method of delivery of chemotherapeutics, drug selection, exposure duration, and tumour pathology make it impractical to use a single, standardised treatment regimen. We aim to summarise the methodologies and limitations of studies encapsulating organoids derived from peritoneal metastases to encourage design considerations that may improve future clinical relevance, standardise protocols, and address translational challenges in personalising treatment strategies. Full article

Summary Statement: A tailored image analysis workflow was applied to quantify cortical organoid health, development, morphology and cellular composition over time. The assessment of cellular composition and viability of stem cell-derived organoid models is a complex but essential approach to understanding the mechanisms of human development and disease. Aim: Our study was motivated by the need for an image-analysis workflow, including high-cell content, high-throughput methods, to measure the architectural features of developing organoids. We assessed stem cell-derived cortical organoids at 4 and 6 months post-induction using immunohistochemistry-labelled sections as the analysis testbed. The workflow leveraged fluorescence imaging tailored to classify cells as viable and dying or non-viable and assign neuronal and astrocytic perinuclear markers to count cells. Results/Outcomes: Image acquisition was accelerated by capturing the organoid slice in 3D using widefield-fluorescence microscopy. This method used computational clearing to resolve nuclear and perinuclear markers and retain their spatial information within the organoid’s heterogeneous structure. The customised workflow analysed over 1.5 million cells using DAPI-stained nuclei, filtering and quantifying viable and non-viable cells and the necrotic-core regions. Temporal analyses of neuronal cell number derived from perinuclear labelling were consistent with organoid maturation from 4 to 6 months of in vitro differentiation. Overall: We have provided a comprehensive and enhanced image analysis workflow for organoid structural evaluation, creating the ability to gather cellular-level statistics in control and disease models. Full article