Organogenesis in a dish: modeling development and disease using organoid technologies

Generation of prostate cancer assembloids modeling the patient-specific tumor microenvironment

Prostate cancer (PC) is the most frequently diagnosed malignancy among men and contributes significantly to cancer-related mortality. While recent advances in in vitro PC modeling systems have been made, there remains a lack of robust preclinical models that faithfully recapitulate the genetic and phenotypic characteristics across various PC subtypes-from localized PC (LPC) to castration-resistant PC (CRPC)-along with associated stromal cells. Here, we established human PC assembloids from LPC and CRPC tissues by reconstituting tumor organoids with corresponding cancer-associated fibroblasts (CAFs), thereby incorporating aspects of the tumor microenvironment (TME). Established PC organoids exhibited high concordance in genomic landscape with parental tumors, and the tumor assembloids showed a higher degree of phenotypic similarity to parental tumors compared to tumor organoids without CAFs. PC assembloids displayed increased proliferation and reduced sensitivity to anti-cancer treatments, indicating that PC assembloids are potent tools for understanding PC biology, investigating the interaction between tumor and CAFs, and identifying personalized therapeutic targets.

HIF-1α-induced long noncoding RNA LINC02776 promotes drug resistance of ovarian cancer by increasing polyADP-ribosylation

BACKGROUND

Chemoresistance remains a major hurdle in ovarian cancer (OC) treatment, as many patients eventually develop resistance to platinum-based chemotherapy and/or PARP inhibitors (PARPi).

METHODS

We performed transcriptome-wide analysis by RNA sequencing (RNA-seq) data of platinum-resistant and -sensitive OC tissues. We demonstrated the role of LINC02776 in platinum resistance in OC cells, mice models and patient-derived organoid (PDO) models.

RESULTS

We identify the long noncoding RNA LINC02776 as a critical factor of platinum resistance. Elevated expression of LINC02776 is observed in platinum-resistant OC and serves as an independent prognostic factor for OC patients. Functionally, silencing LINC02776 reduces proliferation and DNA damage repair in OC cells, thereby enhancing sensitivity to platinum and PARPi in both xenograft mouse models and patient-derived organoid (PDO) models with acquired chemoresistance. Mechanistically, LINC02776 binds to the catalytic domain of poly (ADP-ribose) polymerase 1 (PARP1), promoting PARP1-dependent polyADP-ribosylation (PARylation) and facilitating homologous recombination (HR) restoration. Additionally, high HIF-1α expression in platinum-resistant tissues further stimulates LINC02776 transcription.

CONCLUSIONS

Our findings suggest that targeting LINC02776 represents a promising therapeutic strategy for OC patients who have developed resistance to platinum or PARPi.

KEY POINTS

LINC02776 promotes OC cell proliferation by regulating DNA damage and apoptosis signaling pathways. LINC02776 binds PARP1 to promote DNA damage-triggered PARylation in OC cells. LINC02776 mediates cisplatin and olaparib resistance in OC cells by enhancing PARP1-mediated PARylation activity and regulating the PARP1-mediated HR pathway. The high expression of LINC02776 is induced by HIF-1α in platinum-resistant OC cells and tissues.

Chemical Tomography of Cancer Organoids and Cyto-Proteo-Genomic Development Stages Through Chemical Communication Signals

Organoids mimic human organ function, offering insights into development and disease. However, non-destructive, real-time monitoring is lacking, as traditional methods are often costly, destructive, and low-throughput. In this article, a non-destructive chemical tomographic strategy is presented for decoding cyto-proteo-genomics of organoid using volatile signaling molecules, hereby, Volatile Organic Compounds (VOCs), to indicate metabolic activity and development of organoids. Combining a hierarchical design of graphene-based sensor arrays with AI-driven analysis, this method maps VOC spatiotemporal distribution and generate detailed digital profiles of organoid morphology and proteo-genomic features. Lens- and label-free, it avoids phototoxicity, distortion, and environmental disruption. Results from testing organoids with the reported chemical tomography approach demonstrate effective differentiation between cyto-proteo-genomic profiles of normal and diseased states, particularly during dynamic transitions such as epithelial-mesenchymal transition (EMT). Additionally, the reported approach identifies key VOC-related biochemical pathways, metabolic markers, and pathways associated with cancerous transformations such as aromatic acid degradation and lipid metabolism. This real-time, non-destructive approach captures subtle genetic and structural variations with high sensitivity and specificity, providing a robust platform for multi-omics integration and advancing cancer biomarker discovery.

Light sheet fluorescence microscopy for monitoring drug delivery: Unlocking the developmental phases of embryos

Light sheet fluorescence microscopy (LSFM) has emerged as a transformative imaging technique in the study of drug delivery and embryonic development, offering high-resolution, real-time visualization with minimal phototoxicity. This review examines the application of LSFM in tracking drug pharmacokinetics, tissue-specific targeting, and drug efficacy during critical phases of embryonic development. Recent advancements in fluorescent labeling and machine learning integration have enabled more precise monitoring of drug release, distribution, and interaction with developing tissues. The ability of LSFM to capture long-term dynamics at single-cell resolution has revolutionized drug discovery, especially in nanomedicine and targeted therapies. By integrating LSFM with multimodal imaging and AI-driven data analysis, researchers are now better equipped to explore complex biological processes and optimize drug delivery in a highly controlled, minimally invasive manner. Finally, the review highlights the pivotal role of LSFM in advancing drug delivery research, addressing existing challenges, and unlocking new frontiers in clinical applications.

Addressing myelination disorders: Novel strategies using human 3D peripheral nerve model

Peripheral myelination disorders encompass a variety of disorders that affect myelin sheaths in the peripheral nervous system. The Charcot-Marie-Tooth disease (CMT), the most common inherited peripheral neuropathy, is one of the most prevalent among them. CMT stems from a wide range of genetic causes that disrupt the nerve conduction, leading to progressive muscle weakness and atrophy, sensory loss, and motor function impairment. Historically, the study of these disorders has relied heavily on animal studies, owing to the challenges in accessing human cells. However, the advent of human induced pluripotent stem cell (hiPSC)-derived neuronal cells has addressed these limitations in the realm of peripheral myelination disorders. Despite this, obtaining myelin in these models remains an expensive, time-consuming, and material-intensive process. This study presents a novel, cost-effective method utilizing hiPSC-derived Schwann cells and motor neurons in a three-dimensional culture system. Our method successfully enabled the acquisition of myelin in a control clone within just four weeks, as confirmed by electron microscopy. Furthermore, the utility of these approaches was validated by studying CMT4C, also named AR-CMTde-SH3TC2, the most common recessive demyelinating form of CMT. This revealed defects in Schwann cell support to motor neuron neurite outgrowth and impaired myelination in disease-specific hiPSC-derived lines. This approach offers valuable insights into the pathogenesis of peripheral myelination disorders and provides a platform for testing potential therapeutic strategies.

The biological macromolecules constructed Matrigel for cultured organoids in biomedical and tissue engineering

Matrigel is the most commonly used matrix for 3D organoid cultures. Research on the biomaterial basis of Matrigel for organoid cultures is a highly challenging field. Currently, many studies focus on Matrigel-based biological macromolecules or combinations to construct natural Matrigel and synthetic hydrogel scaffolds based on collagen, peptides, polysaccharides, microbial transglutaminase, DNA supramolecules, and polymers for organoid culture. In this review, we discuss the limitations of both natural and synthetic Matrigel, and describe alternative scaffolds that have been employed for organoid cultures. The patient-derived organoids were constructed in different cancer types and limitations of animal-derived organoids based on the hydrogel or Matrigel. The constructed techniques utilizing 3D bioprinting platforms, air-liquid interface (ALI) culture, microfluidic culture, and organ-on-a-chip platform are summarized. Given the potential of organoids for a wide range of therapeutic, tissue engineering and pharmaceutical applications, it is indeed imperative to develop defined and customized hydrogels in addition to Matrigel.

Human fallopian tube organoids provide a favourable environment for sperm motility

STUDY QUESTION

Does a human fallopian tube (HFT) organoid model offer a favourable apical environment for human sperm survival and motility?

SUMMARY ANSWER

After differentiation, the apical compartment of a new HFT organoid model provides a favourable environment for sperm motility, which is better than commercial media.

WHAT IS KNOWN ALREADY

HFTs are the site of major events that are crucial for achieving an ongoing pregnancy, such as gamete survival and competence, fertilization steps, and preimplantation embryo development. In order to better understand the tubal physiology and tubal factors involved in these reproductive functions, and to improve still suboptimal in vitro conditions for gamete preparation and embryo culture during IVF, we sought to develop an HFT organoid model from isolated adult stem cells to allow spermatozoa co-culture in the apical compartment.

STUDY DESIGN, SIZE, DURATION

Over a 2-year period, fallopian tube tissues were collected for organoid culture purposes from 10 'donor' patients undergoing bilateral salpingectomy by laparoscopy for definitive sterilization. After tissue digestion, isolated cells from the isthmus and ampulla regions were separately seeded in 3D Matrigel and cultured with conventional growth factors for organoid culture and specific factors for differentiation of the female genital tract.

PARTICIPANTS/MATERIALS, SETTING, METHODS

HFT organoids were characterized by light microscopy, scanning and transmission electron microscopy, immunofluorescence, and transcriptome analysis. Following simultaneous organoid culture on specific inserts, spermatozoa from five donors were placed either in control media or in the apical compartment of colon or HFT organoids (isthmus and ampulla separately) for 96 h. Vitality and motility and kinematic parameters were assessed at 0, 48, and 96 h on 200 spermatozoa in each condition and in duplicate and compared using the Wilcoxon test.

MAIN RESULTS AND THE ROLE OF CHANCE

Specific fallopian tube differentiation of our model was confirmed by immunofluorescence, transcriptome analysis, and electron microscopy observations that exhibited ciliated and secretory cells. We succeeded in releasing spermatozoa in the apical compartment of HFT organoids and in recovering them for sperm analysis. Sperm vitality values were similar in HFT organoids and in commercial sperm media. We demonstrated a superiority of the HFT organoid apical compartment for sperm motility compared with other controls (colon organoids, organoid culture media, and conventional commercial sperm fertilization media). At 48 h of incubation, progressive sperm motility was higher in the apical compartment of HFT organoids (ampulla 31% ± 17, isthmus 29% ± 15) than in commercial fertilization media (15% ± 15) (P < 0.05) and compared with all other conditions. At 96 h, progressive sperm motility was almost nil (<1%) in all conditions except for spermatozoa in HFT organoids (P < 0.05): 12% ± 15 and 13% ± 17 in ampulla and isthmus organoids, respectively. Computer-assisted sperm analysis (CASA) analysis also showed that the organoids were able to maintain significantly higher levels of kinematic parameters (curvilinear velocity, average path velocity, straight linear velocity, and amplitude of lateral movement of the head) and therefore more efficient mobility compared with commercial IVF media.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This was an in vitro study in which conditions of organoid culture could not exactly mimic the in vivo environment of the extracellular matrix and vascularization of fallopian tubes.

WIDER IMPLICATIONS OF THE FINDINGS

This work opens up perspectives for better understanding of HFT physiology. For the first time, it highlights the possibility of developing HFT organoids for reproductive purposes. In the future, it could help us to improve gamete fertilizing abilities and embryo culture conditions during human ARTs.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by a grant from the Occitanie region, and by financial allocations from the DEFE and IRSD research teams. The authors have no conflicts of interest to report.

Modeling vascular dynamics at the initial stage of endochondral ossification on a microfluidic chip using a human embryonic-stem-cell-derived organoid

Vascular interactions play a crucial role in embryogenesis, including skeletal development. During endochondral ossification, vascular networks are formed as mesenchymal cells condense and later invade skeletal elements to form the bone marrow. We and other groups developed a model of endochondral ossification by implanting human embryonic stem cell (hESC)-derived sclerotome into immunodeficient mice. However, in vitro models of endochondral ossification, particularly vascular interaction with mesenchymal cells at its initial stage, are yet to be established. Therefore, we developed a method to model the initial stage of endochondral ossification using a microfluidic chip-based platform, with a particular focus on the vascular interaction. On the chip, we found that the fibrin gel helped align mCherry-expressing human umbilical vein endothelial cells (HUVECs) better than the collagen-I gel, suggesting that the fibrin gel is more suitable for the formation of a vascular-like network. The perfusability of the vascular-like networks was partially confirmed using fluorescein isothiocyanate (FITC)-dextran and fluorescent microbeads. We then mixed hESC-derived sclerotome with enhanced green fluorescent protein (EGFP)-expressing HUVECs and applied this mixture on the chip. We named this mixture of cells SH organoids. The SH organoids showed superior abilities to maintain the vascular-like network, which was formed by the mCherry-expressing HUVECs, compared with the sclerotome spheroids on the chip. The EGFP-expressing HUVECs migrated from the SH organoid, formed a vascular-like networks, and partially interacted with the mCherry-expressing vascular-like networks on the chip. Histological analysis showed that SRY-box transcription factor 9 (SOX9) and type I collagen were expressed mutually exclusively in the condensed mesenchymal cells and perichondrial-like cells, respectively. This study demonstrates that our SH organoid-on-a-chip method reproduces vascular networks that are formed at the initial stage of endochondral ossification. This model may provide insights into human endochondral ossification and has potential applications in bone disease modeling and drug screening.

Human health and genetic technology

The 1975 Asilomar conference contributed to the misperception that recombinant DNA (rDNA) technology is inherently risky to human health and the environment. It thus paved the way toward process-based regulation of genetically modified organisms (GMOs), such as in the EU. Initially, this regulatory approach obstructed technological uses of rDNA related to human health. However, regulators gradually softened the rules applicable to laboratories or industrial facilities. This encouraged R&D and production of pharmaceuticals derived from GMOs. Nevertheless, administering pharmaceuticals containing GMOs to patients may still be confronted with burdensome process-based GMO law on the deliberate release of GMOs into the environment. On the other hand, pharmaceutical law may need to be updated regarding, for example, novel gene therapies or xenotransplantation.

3D Bioprinting Inner Ear Organ of Corti Organoids Induce Hair Cell Regeneration

Hearing loss is often regarded as "invisible disability" which seriously affects the quality of life. The majority of hearing loss cases are caused by the damage to inner ear hair cells or connected spiral ganglion cells, and there is a lack of effective treatment measures. In recent years, significant progress has been made in the use of two-dimensional (2D) culture systems to induce the regeneration of auditory cells. However, the regenerated hair cells cannot form effective functional ciliary bundles under the 2D system, let alone establish synaptic contact with spiral ganglion cells, so they cannot truly achieve physiological repair of hearing. In this study, our aim is to construct a three-dimensional (3D) organ of Corti organoid through 3D bioprinting, which combines "3D culture scaffold + multiple induction signals + inner ear stem cells." Then we evaluate the effects of the organoids on the differentiation of inner ear stem cells into auditory cells. We found that the organoids promoted adhesion and growth of inner ear stem cells, as well as the production of hair cells and nerve cells. The research may develop a novel approach for studying auditory cell regeneration and hearing loss repair.

Postnatal development of rat retina: a continuous observation and comparison between the organotypic retinal explant model and in vivo development

JOURNAL/nrgr/04.03/01300535-202503000-00033/figure1/v/2024-06-17T092413Z/r/image-tiff The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures. However, the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies. Thus, we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina. In this study, we showed that postnatal retinal explants undergo normal development, and exhibit a consistent structure and timeline with retinas in vivo. Initially, we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells. We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin, respectively. Ki-67- and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis, and exhibited a high degree of similarity in abundance and distribution between groups. Additionally, we used Ceh-10 homeodomain-containing homolog, glutamate-ammonia ligase (glutamine synthetase), neuronal nuclei, and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells, Müller glia, mature neurons, and microglia, respectively. The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas. Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development. The findings confirm the accuracy and credibility of this model and support its use for long-term, systematic, and continuous observation.

Pheno-Morphological Screening and Acoustic Sorting of 3D Multicellular Aggregates Using Drop Millifluidics

Three-dimensional multicellular aggregates (MCAs) like organoids and spheroids have become essential tools to study the biological mechanisms involved in the progression of diseases. In cancer research, they are now widely used as in vitro models for drug testing. However, their analysis still relies on tedious manual procedures, which hinders their routine use in large-scale biological assays. Here, a novel drop millifluidic approach is introduced to screen and sort large populations containing over one thousand MCAs: ImOCAS (Image-based Organoid Cytometry and Acoustic Sorting). This system utilizes real-time image processing to detect pheno-morphological traits in MCAs. They are then encapsulated in millimetric drops, actuated on-demand using the acoustic radiation force. The performance of ImOCAS is demonstrated by sorting spheroids with uniform sizes from a heterogeneous population, and by isolating organoids from spheroids with different phenotypes. This approach lays the groundwork for high-throughput screening and high-content analysis of MCAs with controlled morphological and phenotypical properties, which promises accelerated progress in biomedical research.

In vivo transplantation of mammalian vascular organoids onto the chick chorioallantoic membrane reveals the formation of a hierarchical vascular network

The dynamic remodeling of the nascent vascular network into a mature hierarchy is essential for embryo survival. Cell behaviors and signaling mechanisms are often investigated with animal models and perfused microchannels, giving insights into this process. To support these studies and enrich our understanding, we demonstrate a complementary approach using vascular organoids. Organoids initially form a primitive endothelial plexus lined with NG2+/PDGFRβ+ mural cell progenitors containing immature pericytes, but there is no formation of large-diameter vessels covered with αSMA+ cells containing immature vascular smooth muscle cells (vSMCs). After transplantation to the chick chorioallantoic membrane, the network reorganizes into a branched architecture with large-diameter vessels covered by αSMA+ cells. We additionally show that blood flow from the host circulation perfuses the organoid. Compared with the developing skin vasculature in mouse embryos, organoids successfully recapitulate vascular morphogenesis, both in vitro and after transplantation. The model described here presents a further approach to enhance the study of vascular remodeling.

Lung organoids in COPD: recent advances and future prospects

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease that is characterized by progressive airflow limitation, a high prevalence, and a high mortality rate. However, the specific mechanisms remain unclear, partly due to the lack of robust data from in vitro experimental models and animal models that do not adequately represent the structure and pathophysiology of the human lung. The recent advancement of lung organoid culture systems has facilitated new avenues for the investigation of COPD. Lung organoids are in vitro models derived from adult stem cells, human pluripotent stem cells, or embryonic stem cells, established through three-dimensional culture. They exhibit a high degree of homology and genetic consistency with human tissues and can better mimic human lungs in terms of function and structure compared to other traditional models. This review will summarise the generation process of lung organoids from different cell sources and their application in COPD research, and provide suggestions for future research directions.

Exploring the landscape of current in vitro and in vivo models and their relevance for targeted radionuclide theranostics

Cancer remains a leading cause of mortality globally, driving ongoing research into innovative treatment strategies. Preclinical research forms the base for developing these novel treatments, using both in vitro and in vivo model systems that are, ideally, as clinically representative as possible. Emerging as a promising approach for cancer management, targeted radionuclide theranostics (TRT) uses radiotracers to deliver (cytotoxic) radionuclides specifically to cancer cells. Since the field is relatively new, more advanced preclinical models are not yet regularly applied in TRT research. This narrative review examines the currently applied in vitro, ex vivo and in vivo models for oncological research, discusses if and how these models are now applied for TRT studies, and whether not yet applied models can be of benefit for the field. A selection of different models is discussed, ranging from in vitro two-dimensional (2D) and three-dimensional (3D) cell models, including spheroids, organoids and tissue slice cultures, to in vivo mouse cancer models, such as cellline-derived models, patient-derived xenograft models and humanized models. Each of the models has advantages and limitations for studying human cancer biology, radiopharmaceutical assessment and treatment efficacy. Overall, there is a need to apply more advanced models in TRT research that better address specific TRT phenomena, such as crossfire and abscopal effects, to enhance the clinical relevance and effectiveness of preclinical TRT evaluations.

Global landscape of hepatic organoid research: A bibliometric and visual study

BACKGROUND

Hepatic organoid-based modelling, through the elucidation of a range of in vivo biological processes and the recreation of the intricate liver microenvironment, is yielding groundbreaking insights into the pathophysiology and personalized medicine approaches for liver diseases.

AIM

This study was designed to analyse the global scientific output of hepatic organoid research and assess current achievements and future trends through bibliometric analysis.

METHODS

Articles were retrieved from the Web of Science Core Collection, and CiteSpace 6.3.R1 was employed to analyse the literature, including outputs, journals, and countries, among others.

RESULTS

Between 2010 and 2024, a total of 991 articles pertaining to hepatic organoid research were published. The journal Hepatology published the greatest number of papers, and journals with an impact factor greater than 10 constituted 60% of the top 10 journals. The United States and Utrecht University were identified as the most prolific country and institution, respectively. Clevers H emerged as the most prolific author, whereas Huch M had the highest number of cocitations, suggesting that both are ideal candidates for academic collaboration. Research on hepatic organoids has exhibited a progressive shift in focus, evolving from initial investigations into model building, differentiation research in stem cells, bile ducts, and progenitor cells, to a broader spectrum encompassing lipid metabolism, single-cell RNA sequencing, and therapeutic applications. The phrases exhibiting citation bursts from 2022 to 2024 include "drug resistance", "disease model", and "patient-derived tumor organoids".

CONCLUSION

Research on hepatic organoids has increased over the past decade and is expected to continue to grow. Key research areas include applications for liver diseases and drug development. Future trends likely to gain focus include patient-derived tumour organoids, disease modelling, and personalized medicine.

Induced pluripotent stem cell-derived mesenchymal stem cells for modeling and treating metabolic associated fatty liver disease and metabolic associated steatohepatitis: Challenges and opportunities

The potential of induced pluripotent stem cells (iPSCs) for modeling and treating metabolic associated fatty liver disease (MAFLD) and metabolic associated steatohepatitis (MASH) is emerging. MAFLD is a growing global health concern, currently with limited treatment options. While primary mesenchymal stem cells hold promise, iPSCs offer a versatile alternative due to their ability to differentiate into various cell types, including iPSC-derived mesenchymal stem cells. However, challenges remain, including optimizing differentiation protocols, ensuring cell safety, and addressing potential tumorigenicity risks. In addition, iPSCs offer the possibility to generate complex cellular models, including three-dimensional organoid models, which are closer representations of the human disease than animal models. Those models would also be valuable for drug discovery and personalized medicine approaches. Overall, iPSCs and their derivatives offer new perspectives for advancing MAFLD/MASH research and developing novel therapeutic strategies. Further research is needed to overcome current limitations and translate this potential into effective clinical applications.

Developing 3D bioprinting for organs-on-chips

Organs-on-chips (OoCs) have significantly advanced biomedical research by precisely reconstructing human microphysiological systems with biomimetic functions. However, achieving greater structural complexity of cell cultures on-chip for enhanced biological mimicry remains a challenge. To overcome these challenges, 3D bioprinting techniques can be used in directly building complex 3D cultures on chips, facilitating the in vitro engineering of organ-level models. Herein, we review the distinctive features of OoCs, along with the technical and biological challenges associated with replicating complex organ structures. We discuss recent bioprinting innovations that simplify the fabrication of OoCs while increasing their architectural complexity, leading to breakthroughs in the field and enabling the investigation of previously inaccessible biological problems. We highlight the challenges for the development of 3D bioprinted OoCs, concluding with a perspective on future directions aimed at facilitating their clinical translation.

Organoids from pluripotent stem cells and human tissues: When two cultures meet each other

Human organoids are a widely used tool in cell biology to study homeostatic processes, disease, and development. The term organoids covers a plethora of model systems from different cellular origins that each have unique features and applications but bring their own challenges. This review discusses the basic principles underlying organoids generated from pluripotent stem cells (PSCs) as well as those derived from tissue stem cells (TSCs). We consider how well PSC- and TSC-organoids mimic the different intended organs in terms of cellular complexity, maturity, functionality, and the ongoing efforts to constitute predictive complex models of in vivo situations. We discuss the advantages and limitations associated with each system to answer different biological questions including in the field of cancer and developmental biology, and with respect to implementing emerging advanced technologies, such as (spatial) -omics analyses, CRISPR screens, and high-content imaging screens. We postulate how the two fields may move forward together, integrating advantages of one to the other.

Advances and Challenges in Modeling Autosomal Dominant Polycystic Kidney Disease: A Focus on Kidney Organoids

Autosomal dominant polycystic kidney disease (ADPKD) is a prevalent hereditary disorder characterized by distinct phenotypic variability that has posed challenges for advancing in-depth research. Recent advancements in kidney organoid construction technologies have enabled researchers to simulate kidney development and create simplified in vitro experimental environments, allowing for more direct observation of how genetic mutations drive pathological phenotypes and disrupt physiological functions. Emerging technologies, such as microfluidic bioreactor culture systems and single-cell transcriptomics, have further supported the development of complex ADPKD organoids, offering robust models for exploring disease mechanisms and facilitating drug discovery. Nevertheless, significant challenges remain in constructing more accurate ADPKD disease models. This review will summarize recent advances in ADPKD organoid construction, focusing on the limitations of the current techniques and the critical issues that need to be addressed for future breakthroughs. New and Noteworthy: This review presents recent advancements in ADPKD organoid construction, particularly iPSC-derived models, offering new insights into disease mechanisms and drug discovery. It focuses on challenges such as limited vascularization and maturity, proposing potential solutions through emerging technologies. The ongoing optimization of ADPKD organoid models is expected to enhance understanding of the disease and drive breakthroughs in disease mechanisms and targeted therapy development.

Advancing Glioblastoma Research with Innovative Brain Organoid-Based Models

Glioblastoma (GBM) is a relatively rare but highly aggressive form of brain cancer characterized by rapid growth, invasiveness, and resistance to standard therapies. Despite significant progress in understanding its molecular and cellular mechanisms, GBM remains one of the most challenging cancers to treat due to its high heterogeneity and complex tumor microenvironment. To address these obstacles, researchers have employed a range of models, including in vitro cell cultures and in vivo animal models, but these often fail to replicate the complexity of GBM. As a result, there has been a growing focus on refining these models by incorporating human-origin cells, along with advanced genetic techniques and stem cell-based bioengineering approaches. In this context, a variety of GBM models based on brain organoids were developed and confirmed to be clinically relevant and are contributing to the advancement of GBM research at the preclinical level. This review explores the preparation and use of brain organoid-based models to deepen our understanding of GBM biology and to explore novel therapeutic approaches. These innovative models hold significant promise for improving our ability to study this deadly cancer and for advancing the development of more effective treatments.

Anticancer potentials of chaga and notoginseng against dog bladder cancer organoids

Muscle-invasive bladder cancer (MIBC) is a common form of BC in dogs. Adjuvant chemotherapy administration is commonly applied in MIBC cases, but patients sometimes experience treatment failure and recurrence. Therefore, supplements with anticancer properties, such as traditional Chinese medicines (TCMs), are required, and they have been widely used in Japanese human medicine and may be useful in veterinary medicine. Furthermore, organoid cultures can mimic the characteristics of their original tissues, such as self-renewal and organization. We previously established a novel experimental model for MIBC using a dog BC organoid (DBCO) culture. Herein, we examined the antiproliferative effects and mechanisms of 39 substances, consisting of TCMs, TCM supplements, and crude drug extracts, on DBCOs. Among the TCMs, D3 (also known as Shibe-ria), which is a mixture of chaga (Inonotus obliquus) and notoginseng (Panax notoginseng), significantly diminished the cell viability of DBCOs. The expression of BC stem cell markers, CD44 and SOX2, was reduced considerably in the D3-treated DBCOs. Among the components of D3, chaga exerted an antiproliferative effect on DBCO, whereas notoginseng did not. The administration of D3 also significantly reduced the volume of DBCO xenografted tumors in mice in vivo. Overall, D3 may have benefits as a natural anticancer supplement in veterinary medicine.

Purified adipose tissue-derived extracellular vesicles facilitate adipose organoid vascularization through coordinating adipogenesis and angiogenesis

One of the major challenges in the way of better fabricating vascularized adipose organoids is the destructive effect of adipogenic differentiation on preformed vasculature, which probably stems from the discrepancy between thein vivophysiological microenvironment and thein vitroculture conditions. As an intrinsic component of adipose tissue (AT), adipose tissue-derived extracellular vesicles (AT-EVs) have demonstrated both adipogenic and angiogenic ability in recent studies. However, whether AT-EVs could be employed to coordinate the angiogenesis and adipogenesis in the vascularization of adipose organoids remains largely unexplored. Herein, we present an efficient method for isolating higher-purity AT-EV preparations from lipoaspirates, and verify the superiority of AT-EV preparations' angiogenic and adipogenic capabilities over those from unpurified lipoaspirates. Next, in the spheroid culture model, it was discovered that the addition of AT-EVs could effectively improve the aggregation through enhancing intercellular adhesion of monoculture spheroids composed of human umbilical vascular endothelial cells (HUVECs), and helped produce vascularized adipose organoids with proper lipolysis and glucose uptake ability in the coculture spheroids comprised of adipose-derived stem cells (ADSCs) and HUVECs. Subsequently, it was observed that AT-EVs could exert a retaining effect on the vasculature of prevascularized coculture spheroids cultured in an adipogenic environment, compared to the reduced vascular networks where AT-EVs were absent. Altogether, these results indicate that AT-EVs, by means of releasing bioactive molecules that emulate thein vivomicroenvironment, can modify non-replicativein vitromicroenvironments, coordinatein vitroadipogenesis and angiogenesis, and facilitate the fabrication of vascularized adipose organoids.

Organoid, organ-on-a-chip and traditional Chinese medicine

In the past few years, the emergence of organoids and organ-on-a-chip (OOAC) technologies, which are complementary to animal models and two-dimensional cell culture methods and can better simulate the internal environment of the human body, provides a new platform for traditional Chinese medicine (TCM) studies. Organoids and OOAC techniques have been increasingly applied in the fields of drug screening, drug assessment and development, personalized therapies, and developmental biology, and there have been some application cases in the TCM studies. In this review, we summarized the current status of using organoid and OOAC technologies in TCM research and provide key insights for future study. It is believed that organoid and OOAC technologies will play more and more important roles in research and make greater contributions to the innovative development of TCM.

Hepatobiliary organoid research: the progress and applications

Organoid culture has emerged as a forefront technology in the life sciences field. As "in vitro micro-organs", organoids can faithfully recapitulate the organogenesis process, and conserve the key structure, physiological function and pathological state of the original tissue or organ. Consequently, it is widely used in basic and clinical studies, becoming important preclinical models for studying diseases and developing therapies. Here, we introduced the definition and advantages of organoids and described the development and advances in hepatobiliary organoids research. We focus on applying hepatobiliary organoids in benign and malignant diseases of the liver and biliary tract, drug research, and regenerative medicine to provide valuable reference information for the application of hepatobiliary organoids. Despite advances in research and treatment, hepatobiliary diseases including carcinoma, viral hepatitis, fatty liver and bile duct defects have still been conundrums of the hepatobiliary field. It is necessary and crucial to study disease mechanisms, establish efficient and accurate research models and find effective treatment strategies. The organoid culture technology shed new light on solving these issues. However, the technology is not yet mature, and many hurdles still exist that need to be overcome. The combination with new technologies such as CRISPR-HOT, organ-on-a-chip may inject new vitality into future development.

Tahyna virus: an emerging threat to public health

Tahyna virus (TAHV), a member of the California serogroup of the genus Orthobunyavirus, is an arbovirus that is capable of causing a range of symptoms from mild febrile illnesses to severe neuroinvasive disease. It was first isolated in Europe and has a holarctic distribution, spanning Central Europe, Asia, and Africa. Central Europe has reported the highest reported human seropositivity rate, reaching 30%. Phylogenetic analysis has revealed a close relationship between TAHV and Lumbo virus (LUMV), with 94% amino acid sequence identity in their N proteins. TAHV is mainly transmitted by Aedes mosquitoes, and its vertebrate hosts include hares, rabbits, hedgehogs, and rodents. Flooding during the summer months due to climate change may be a catalyst for the spread of the virus. Despite the enormous potential threat of TAHV and its potential to cause meningitis, there is a notable dearth of information regarding its actual prevalence, the number of symptomatic cases, and its clinical manifestations in humans and animals. To date, no deaths have been attributed to TAHV, which might contribute to an underestimation of its public health significance. Given the anticipated future changes in climatic conditions, TAHV could pose a health threat in Europe and elsewhere. In this review, we summarize recent advancements in TAHV research, highlighting the need for enhanced research and resource allocation for its prevention and control.

Biomaterial-assisted organoid technology for disease modeling and drug screening

Developing disease models and screening for effective drugs are key areas of modern medical research. Traditional methodologies frequently fall short in precisely replicating the intricate architecture of bodily tissues and organs. Nevertheless, recent advancements in biomaterial-assisted organoid technology have ushered in a paradigm shift in biomedical research. This innovative approach enables the cultivation of three-dimensional cellular structures in vitro that closely emulate the structural and functional attributes of organs, offering physiologically superior models compared to conventional techniques. The evolution of biomaterials plays a pivotal role in supporting the culture and development of organ tissues, thereby facilitating more accurate disease state modeling and the rigorous evaluation of drug efficacy and safety profiles. In this review, we will explore the roles that various biomaterials play in organoid development, examine the fundamental principles and advantages of utilizing these technologies in constructing disease models, and highlight recent advances and practical applications in drug screening using disease-specific organoid models. Additionally, the challenges and future directions of organoid technology are discussed. Through continued research and innovation, we aim to make remarkable strides in disease treatment and drug development, ultimately enhancing patient quality of life.

Lung regeneration and lung bioengineering

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease affects more than 65 million people worldwide. Lung transplantation is the only definitive treatment. However, donor availability is limited in meeting the demand.

RECENT FINDINGS

Lung regeneration is a new therapeutic strategy that uses the patient's stem cells to replace dysfunctional tissue and restore functional lung tissue rather than alleviate symptoms. Organoids are a new promising target for human lung regeneration. The AEP cells are isolated from human lung tissue for growth. The 3D organ-like structures conserve the alveolar progenitor's capacity to proliferate and differentiate into various epithelial cell types.Bioengineered organs, from a patient's cells, allow for customized biocompatible organs-on-demand without the need for immunosuppressive therapy. The concept involves the creation of a form of 3D tissue scaffold, to be populated by cells of the desired tissue to be transplanted into the patient, allowing for function as closely to the native organ as possible.

SUMMARY

The lung's ability to regenerate extensively after injury suggests that this capability could be promoted in diseases in which loss of lung tissue occurs. Lung bioengineering offers the potential to drastically extend life expectancy in patients with end-stage lung disease. If lung reengineering were successful, it would revolutionize the world of transplantation.

A systematic review on the culture methods and applications of 3D tumoroids for cancer research and personalized medicine

Cancer is a highly heterogeneous disease, and thus treatment responses vary greatly between patients. To improve therapy efficacy and outcome for cancer patients, more representative and patient-specific preclinical models are needed. Organoids and tumoroids are 3D cell culture models that typically retain the genetic and epigenetic characteristics, as well as the morphology, of their tissue of origin. Thus, they can be used to understand the underlying mechanisms of cancer initiation, progression, and metastasis in a more physiological setting. Additionally, co-culture methods of tumoroids and cancer-associated cells can help to understand the interplay between a tumor and its tumor microenvironment. In recent years, tumoroids have already helped to refine treatments and to identify new targets for cancer therapy. Advanced culturing systems such as chip-based fluidic devices and bioprinting methods in combination with tumoroids have been used for high-throughput applications for personalized medicine. Even though organoid and tumoroid models are complex in vitro systems, validation of results in vivo is still the common practice. Here, we describe how both animal- and human-derived tumoroids have helped to identify novel vulnerabilities for cancer treatment in recent years, and how they are currently used for precision medicine.

Development and application of 3D cardiac tissues derived from human pluripotent stem cells

Recently human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have become an attractive platform to evaluate drug responses for cardiotoxicity testing and disease modeling. Moreover, three-dimensional (3D) cardiac models, such as engineered heart tissues (EHTs) developed by bioengineering approaches, and cardiac spheroids (CSs) formed by spherical aggregation of hPSC-CMs, have been established as useful tools for drug discovery and transplantation. These 3D models overcome many of the shortcomings of conventional 2D hPSC-CMs, such as immaturity of the cells. Cardiac organoids (COs), like other organs, have also been studied to reproduce structures that resemble a heart in vivo more closely and optimize various culture conditions. Heart-on-a-chip (HoC) developed by a microfluidic chip-based technology that enables real-time monitoring of contraction and electrical activity, provides multifaceted information that is essential for capturing natural tissue development in vivo. Recently, 3D experimental systems have been developed to study organ interactions in vitro. This review aims to discuss the developments and advancements of hPSC-CMs and 3D cardiac tissues.

Human Induced Pluripotent Stem Cells: Directed Differentiation Methods and Applications in Brain Diseases

Human induced pluripotent stem cells (hiPSCs), similar to embryonic stem cells, are a class of pluripotent stem cells with the potential to differentiate into various kinds of cells. Because the application of hiPSCs obtained by reprogramming patients' somatic cells in the treatment of brain diseases bypasses the ethical constraints on the use of embryonic stem cells and mitigates immune rejection, hiPSCs have profound clinical application prospects. In this review, we first summarized the differentiation methods of hiPSCs into different kinds of neurons, and secondly discussed the application of hiPSCs in several brain disease models, so as to provide a reference for the future application of hiPSCs in the studies and treatment of brain diseases.

Micro-physiological system of human lung: The current status and application to drug discovery

Various attempts have been made to elucidate the mechanisms of human lung development, its physiological functions, and diseases, in the hope of new drug discovery. Recent technological advancements in experimental animals, cell culture, gene editing, and analytical methods have provided new insights and therapeutic strategies. However, the results obtained from animal experiments are often inconsistent with those obtained from human data because of reproducibility issues caused by structural and physiological differences between mice and humans. In addition, it is not possible to accurately reproduce the internal environment of the human lung structure using conventional two-dimensional (2D) or three-dimensional (3D) cell culture methods. As a result, the micro-physiological system (MPS) technology, such as "lung-on-a-chip" that can culture human cells in a state close to human body environment have been developed, and its applications to disease models, toxicological studies, and drug discovery are accelerated worldwide. Here, we focus on the mimetics of the lung, including "lung-on-a-chip" technology, and review their recent progress, achievements and challenges. Finally, we discuss the role of these chips in drug discovery for refractory lung diseases.

Matrix Viscoelasticity Controls Differentiation of Human Blood Vessel Organoids into Arterioles and Promotes Neovascularization in Myocardial Infarction

Stem cell-derived blood vessel organoids are embedded in extracellular matrices to stimulate vessel sprouting. Although vascular organoids in 3D collagen I-Matrigel gels are currently available, they are primarily capillaries composed of endothelial cells (ECs), pericytes, and mesenchymal stem-like cells, which necessitate mature arteriole differentiation for neovascularization. In this context, the hypothesis that matrix viscoelasticity regulates vascular development is investigated in 3D cultures by encapsulating blood vessel organoids within viscoelastic gelatin/β-CD assembly dynamic hydrogels or methacryloyl gelatin non-dynamic hydrogels. The vascular organoids within the dynamic hydrogel demonstrate enhanced angiogenesis and differentiation into arterioles containing smooth muscle cells. The dynamic hydrogel mechanical microenvironment promotes vascular patterning and arteriolar differentiation by elevating notch receptor 3 signaling in mesenchymal stem cells and downregulating platelet-derived growth factor B expression in ECs. Transplantation of vascular organoids in vivo, along with the dynamic hydrogel, leads to the reassembly of arterioles and restoration of cardiac function in infarcted hearts. These findings indicate that the viscoelastic properties of the matrix play a crucial role in controlling the vascular organization and differentiation processes, suggesting an exciting potential for its application in regenerative medicine.

Dysregulation of mTOR signalling is a converging mechanism in lissencephaly

Cerebral cortex development in humans is a highly complex and orchestrated process that is under tight genetic regulation. Rare mutations that alter gene expression or function can disrupt the structure of the cerebral cortex, resulting in a range of neurological conditions1. Lissencephaly ('smooth brain') spectrum disorders comprise a group of rare, genetically heterogeneous congenital brain malformations commonly associated with epilepsy and intellectual disability2. However, the molecular mechanisms underlying disease pathogenesis remain unknown. Here we establish hypoactivity of the mTOR pathway as a clinically relevant molecular mechanism in lissencephaly spectrum disorders. We characterized two types of cerebral organoid derived from individuals with genetically distinct lissencephalies with a recessive mutation in p53-induced death domain protein 1 (PIDD1) or a heterozygous chromosome 17p13.3 microdeletion leading to Miller-Dieker lissencephaly syndrome (MDLS). PIDD1-mutant organoids and MDLS organoids recapitulated the thickened cortex typical of human lissencephaly and demonstrated dysregulation of protein translation, metabolism and the mTOR pathway. A brain-selective activator of mTOR complex 1 prevented and reversed cellular and molecular defects in the lissencephaly organoids. Our findings show that a converging molecular mechanism contributes to two genetically distinct lissencephaly spectrum disorders.

Advances in lacrimal gland organoid development: Techniques and therapeutic applications

The human lacrimal gland (LG), located above the outer orbital region within the frontal bone socket, is essential in maintaining eye surface health and lubrication. It is firmly anchored to the orbital periosteum by the connective tissue, and it is vital for protecting and lubricating the eye by secreting lacrimal fluid. Disruption in the production, composition, or secretion of lacrimal fluid can lead to dry eye syndrome, a condition characterized by ocular discomfort and potential eye surface damage. This review explores the recent advancements in LG organoid generation using tissues and stem cells, highlighting cutting-edge techniques in biomaterial-based and scaffold-free technologies. Additionally, we shed light on the complex pathophysiology of LG dysfunction, providing insights into the LG physiological roles while identifying strategies for generating LG organoids and exploring their potential clinical applications. Alterations in LG morphology or secretory function can affect the tear film stability and quality, leading to various ocular pathological conditions. This comprehensive review underlines the critical crosslink of LG organoid development with disease modeling and drug screening, underscoring their potential for advancing therapeutic applications.

Advancements in Microphysiological systems: Exploring organoids and organ-on-a-chip technologies in drug development -focus on pharmacokinetics related organs

This study explored the evolving landscape of Microphysiological Systems (MPS), with a focus on organoids and organ-on-a-chip (OoC) technologies, which are promising alternatives to animal testing in drug discovery. MPS technology offers in vitro models with high physiological relevance, simulating organ function for pharmacokinetic studies. Organoids composed of 3D cell aggregates and OoCs mimicking in vivo environments based on microfluidic platforms represent the forefront of MPS. This paper provides a comprehensive overview of their application in studying the gut, liver, and kidney and their challenges in becoming reliable alternatives to in vivo models. Although MPS technology is not yet fully comparable to in vivo systems, its continued development, aided by in silico, automation, and AI approaches, is anticipated to bring about further advancements. Collaboration across multiple disciplines and ongoing regulatory discussions will be crucial in driving MPS toward practical and ethical applications in biomedical research and drug development.

Liver organoids: Current advances and future applications for hepatology

The creation of self-organizing liver organoids represents a significant, although modest, step toward addressing the ongoing organ shortage crisis in allogeneic liver transplantation. However, researchers have recognized that achieving a fully functional whole liver remains a distant goal, and the original ambition of organoid-based liver generation has been temporarily put on hold. Instead, liver organoids have revolutionized the field of hepatology, extending their influence into various domains of precision and molecular medicine. These 3D cultures, capable of replicating key features of human liver function and pathology, have opened new avenues for human-relevant disease modeling, CRISPR gene editing, and high-throughput drug screening that animal models cannot accomplish. Moreover, advancements in creating more complex systems have led to the development of multicellular assembloids, dynamic organoid-on-chip systems, and 3D bioprinting technologies. These innovations enable detailed modeling of liver microenvironments and complex tissue interactions. Progress in regenerative medicine and transplantation applications continues to evolve and strives to overcome the obstacles of biocompatibility and tumorigenecity. In this review, we examine the current state of liver organoid research by offering insights into where the field currently stands, and the pivotal developments that are shaping its future.

The importance of preclinical models in cholangiocarcinoma

Cholangiocarcinoma (CCA) is an adenocarcinoma of the hepatobiliary system with a grim prognosis. Incidence is rising globally and surgery is currently the only curative treatment, but is only available for patients who are fit and diagnosed in an early-stage of disease progression. Great importance has been placed on developing preclinical models to help further our understanding of CCA and potential treatments to improve therapeutic outcomes. Preclinical models of varying complexity and cost have been established, ranging from more simplistic in vitro 2D CCA cell lines in culture, to more complex in vivo genetically engineered mouse models. Currently there is no single model that faithfully recaptures the complexities of human CCA and the in vivo tumour microenvironment. Instead a multi-model approach should be used when designing preclinical trials to study CCA and potential therapies.

Senolytics rejuvenate aging cardiomyopathy in human cardiac organoids

BACKGROUND

Human cardiac organoids closely replicate the architecture and function of the human heart, offering a potential accurate platform for studying cellular and molecular features of aging cardiomyopathy. Senolytics have shown potential in addressing age-related pathologies but their potential to reverse aging-related human cardiomyopathy remains largely unexplored.

METHODS

We employed human iPSC-derived cardiac organoids (hCOs/hCardioids) to model doxorubicin(DOXO)-induced cardiomyopathy in an aged context. hCardioids were treated with DOXO and subsequently with a combination of two senolytics: dasatinib (D) and quercetin (Q).

RESULTS

DOXO-treated hCardioids exhibited significantly increased oxidative stress, DNA damage (pH2AX), cellular senescence (p16INK4A) and decreased cell proliferation associated with a senescence-associated secretory phenotype (SASP). DOXO-treated hCardioids were considerably deprived of cardiac progenitors and displayed reduced cardiomyocyte proliferation as well as contractility. These distinctive aging-associated characteristics were confirmed by global RNA-sequencing analysis. Treatment with D+Q reversed these effects, reducing oxidative stress and senescence markers, alleviating SASP, and restoring hCardioids viability and function. Additionally, senolytics replenished cardiac progenitors and reversed the cardiomyocyte proliferation deficit.

CONCLUSIONS

Doxorubicin triggers an age-associated phenotype in hCardioids reliably modelling the main cellular and molecular features of aging cardiomyopathy. Senescence is a key mechanism of the aged-hCOs phenotype as senolytics rejuvenated aged-hCardioids restoring their structure and function while reverting the age-associated regenerative deficit.

The Use of Gut Organoids: To Study the Physiology and Disease of the Gut Microbiota

The intestinal flora has attracted much attention in recent years. An imbalance in the intestinal flora can cause not only intestinal diseases but also cause a variety of parenteral diseases, such as endocrine diseases, nervous system diseases and cardiovascular diseases. Research on the mechanism of disease is likely to be hampered by sample accessibility, ethical issues, and differences between cellular animal and physiological studies. However, advances in stem cell culture have made it possible to reproduce 3D human tissues in vitro that mimic the cellular, anatomical and functional characteristics of real organs. Recent studies have shown that organoids can be used to simulate the development and disease of the gut and intestinal flora and have a wide range of applications in intestinal flora physiology and disease. Intestinal organoids provide a preeminent in vitro model system for cultivating microbiota that influence GI physiology, as well as for understanding how they encounter intestinal epithelial cells and cause disease. The mechanistic details obtained from such modelling may provide new avenues for the prevention and treatment of many gastrointestinal (GI) disorders. Researchers are now starting to take inspiration from other fields, such as bioengineering, and the rise of interdisciplinary approaches, including organoid chip technology and microfluidics, has greatly accelerated the development of organoids to generate intestinal organoids that are more physiologically relevant and suitable for gut microbiota studies. Here, we describe the development of organoid models of gut biology and the application of organoids to study the pathophysiology of diseases caused by intestinal dysbiosis.

In vitro cellular model systems provide a promising alternative to animal experiments for studying the intestine-organ axis

Limiting animal experiments is essential for ethical issues and also because scientific evidence highlights the discrepancies between human and animal metabolism. This review aims to provide a critical discussion of the strengths and limitations of the most appropriate in vitro intestine model to answer complex research questions in pharmaceutical and nutraceutical fields. This review describes the components contributing to the definition of the gut barrier structure, from the outer mucus layer to the inner part of lamina propria, including endothelial and neuronal networks. We conclude that the main advantage of these co-culture models is their versatility since they are modulable systems in which each component can be added, changed, or removed to reproduce a specific physiological condition each time. Additionally, we compare intestinal organoid models and microfluidic systems with well-established co-culture models.

High-throughput solutions in tumor organoids: from culture to drug screening

Tumor organoids have emerged as an ideal in vitro model for patient-derived tissues, as they recapitulate the characteristics of the source tumor tissue to a certain extent, offering the potential for personalized tumor therapy and demonstrating significant promise in pharmaceutical research and development. However, establishing and applying this model involves multiple labor-intensive and time-consuming experimental steps and lacks standardized protocols and uniform identification criteria. Thus, high-throughput solutions are essential for the widespread adoption of tumor organoid models. This review provides a comprehensive overview of current high-throughput solutions across the entire workflow of tumor organoids, from sampling and culture to drug screening. Furthermore, we explore various technologies that can control and optimize single-cell preparation, organoid culture, and drug screening with the ultimate goal of ensuring the automation and high efficiency of the culture system and identifying more effective tumor therapeutics.

Engineering the 3D structure of organoids

Organoids form through the sel f-organizing capabilities of stem cells to produce a variety of differentiated cell and tissue types. Most organoid models, however, are limited in terms of the structure and function of the tissues that form, in part because it is difficult to regulate the cell type, arrangement, and cell-cell/cell-matrix interactions within these systems. In this article, we will discuss the engineering approaches to generate more complex organoids with improved function and translational relevance, as well as their advantages and disadvantages. Additionally, we will explore how biofabrication strategies can manipulate the cell composition, 3D organization, and scale-up of organoids, thus improving their utility for disease modeling, drug screening, and regenerative medicine applications.

Current Treatment Regimens and Promising Molecular Therapies for Chronic Hepatobiliary Diseases

Chronic hepatobiliary damage progressively leads to fibrosis, which may evolve into cirrhosis and/or hepatocellular carcinoma. The fight against the increasing incidence of liver-related morbidity and mortality is challenged by a lack of clinically validated early-stage biomarkers and the limited availability of effective anti-fibrotic therapies. Current research is focused on uncovering the pathogenetic mechanisms that drive liver fibrosis. Drugs targeting molecular pathways involved in chronic hepatobiliary diseases, such as inflammation, hepatic stellate cell activation and proliferation, and extracellular matrix production, are being developed. Etiology-specific treatments, such as those for hepatitis B and C viruses, are already in clinical use, and efforts to develop new, targeted therapies for other chronic hepatobiliary diseases are ongoing. In this review, we highlight the major molecular changes occurring in patients affected by metabolic dysfunction-associated steatotic liver disease, viral hepatitis (Delta virus), and autoimmune chronic liver diseases (autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis). Further, we describe how this knowledge is linked to current molecular therapies as well as ongoing preclinical and clinical research on novel targeting strategies, including nucleic acid-, mesenchymal stromal/stem cell-, and extracellular vesicle-based options. Much clinical development is obviously still missing, but the plethora of promising potential treatment strategies in chronic hepatobiliary diseases holds promise for a future reversal of the current increase in morbidity and mortality in this group of patients.

Human iPSC-derived microglial cells protect neurons from neurodegeneration in long-term cultured adhesion brain organoids

Brain organoid models have greatly facilitated our understanding of human brain development and disease. However, key brain cell types, such as microglia, are lacking in most brain organoid models. Because microglia have been shown to play important roles in brain development and pathologies, attempts have been made to add microglia to brain organoids through co-culture. However, only short-term microglia-organoid co-cultures can be established, and it remains challenging to have long-lasting survival of microglia in organoids to mimic long-term residency of microglia in the brain. In this study, we developed an adhesion brain organoid (ABO) platform that allows prolonged culture of brain organoids (greater than a year). Moreover, the long-term (LT)-ABO system contains abundant astrocytes and can support prolonged survival and ramification of microglia. Furthermore, we showed that microglia in the LT-ABO could protect neurons from neurodegeneration by increasing synaptic density and reducing p-Tau level and cell death in the LT-ABO. Therefore, the microglia-containing LT-ABO platform generated in this study provides a promising human cellular model for studying neuron-glia and glia-glia interactions in brain development and the pathogenesis of neurodegenerative diseases such as Alzheimer's disease.

3D Cell Culture Models as a Platform for Studying Tumor Progression, Testing Treatment Responses, and Discovering Biomarkers

In this chapter, we present a detailed protocol for establishing a three-dimensional (3D) multicellular tumor spheroids (MCTSs) model to simulate the tumor microenvironment (ME) associated with metabolic dysfunction-associated steatotic liver disease (MASLD) for the study of hepatocellular carcinoma (HCC) and colorectal cancer (CRC) cell aggressiveness, growth, and metastasis potential. The MASLD microenvironment (MASLD-ME) is recreated by embedding hepatic stellate cells in a collagen I matrix within a Boyden chamber system. The metabolic medium mimics MASLD conditions, enriched with high glucose, fructose, insulin, and fatty acids, to simulate metabolic stresses associated with the disease.In the protocol, cancer cells are loaded in the upper compartment to analyze their migration toward the MASLD-ME, thereby facilitating studies on cancer cell invasiveness and metastatic capacity. This method offers an adaptable, reproducible model to research disease progression and investigate therapeutic interventions, contributing to preclinical research on MASLD-related liver cancer pathophysiology and potential drug responses.

Modeling the Effect of Cannabinoid Exposure During Human Neurodevelopment Using Bidimensional and Tridimensional Cultures

Our knowledge about the consumption of cannabinoids during pregnancy lacks consistent evidence to determine whether it compromises neurodevelopment. Addressing this task is challenging and complex since pregnant women display multiple confounding factors that make it difficult to identify the real effect of cannabinoids' consumption. Recent studies shed light on this issue by using pluripotent stem cells of human origin, which can recapitulate human neurodevelopment. These revolutionary platforms allow studying how exogenous cannabinoids could alter human neurodevelopment without ethical concerns and confounding factors. Here, we review the information to date on the clinical studies about the impact of exogenous cannabinoid consumption on human brain development and how exogenous cannabinoids alter nervous system development in humans using cultured pluripotent stem cells as 2D and 3D platforms to recapitulate brain development.

Generation of self-organized neuromusculoskeletal tri-tissue organoids from human pluripotent stem cells

The human body function requires crosstalk between different tissues. An essential crosstalk is in the neuromusculoskeletal (NMS) axis involving neural, muscular, and skeletal tissues, which is challenging to model using human cells. Here, we describe the generation of three-dimensional, NMS tri-tissue organoids (hNMSOs) from human pluripotent stem cells through a co-development strategy. Staining, single-nucleus RNA sequencing, and spatial transcriptome profiling revealed the co-emergence and self-organization of neural, muscular, and skeletal lineages within individual organoids, and the neural domains of hNMSOs obtained a ventral-specific identity and produced motor neurons innervating skeletal muscles. The neural, muscular, and skeletal regions of hNMSOs exhibited maturation and established functional connections during development. Notably, structural, functional, and transcriptomic analyses revealed that skeletal support in hNMSOs benefited human muscular development. Modeling with hNMSOs also unveiled the neuromuscular alterations following pathological skeletal degeneration. Together, our study provides an accessible experimental model for future studies of human NMS crosstalk and abnormality.