Tool For Drug Screening Research Articles

Drug Discovery and Screening Tool Development for Tauopathies by Focusing on Pathogenic Tau Repeat 3 Oligomers.

Comprehending early amyloidogenesis is essential for the development of effective therapeutic strategies. In tauopathies like Alzheimer's disease (AD), the abnormal accumulation of tau protein is initiated by pathological tau seeds. Mounting evidence implies that the microtubule binding domain, consisting of three to four repeats, plays a pivotal role in this process, yet the exact region driving the formation of pathogenic species needs to be further scrutinized. Here, we chemically synthesized individual tau repeats to identify those exhibiting pathogenic prion-like characteristics. Notably, repeat 3 (R3) displayed a remarkable propensity to polymerize, form toxic filaments, and induce cognitive impairment, even in the absence of an aggregation-promoting inducer, highlighting its physiological relevance. Additionally, oligomeric R3 was identified as a particularly pathological form, prompting the establishment of a screening platform. Through screening, tolcapone was found to possess therapeutic efficacy against pathological tau aggregates in PS19 transgenic mice. This screening platform provides a valuable avenue for identifying compounds that selectively interact with peptides implicated in the progression of tauopathies.

Expression and purification of SARS-CoV-2 receptor binding domain in Escherichia coli for diagnostic and therapeutic purposes

Background and purpose: SARS-CoV-2 causes a severe respiratory disease known as COVID-19 and is responsible for a global viral pandemic. The SARS-CoV-2 receptor binding domain (RBD) is located on the spike protein, which identifies and binds to the angiotensin-converting enzyme 2 (ACE2) receptor. The RBD is an important target for developing virus-neutralizing antibodies, vaccines, and inhibitors. Experimental approach: In this study, recombinant SARS-CoV-2 RBD was expressed in E. coli BL21 (DE3) and purified and its binding activity was determined. Purification was conducted using the Ni-NTA column. ELISA. flow cytometry assays were set to evaluate the binding ability of recombinant RBD to different anti-RBD antibodies and native ACE2 receptors on HEK293A cells, respectively. Findings/Results: The SDS-PAGE analysis revealed the corresponding band at 27 kDa in the culture after induction with 0.7 mM IPTG, while the corresponding band was not observed in the culture without IPTG induction. ELISA results showed that antibodies produced in the human sera could bind to the recombinant RBD protein and the commercial anti-RBD antibody. Also, flow cytometry analysis revealed that the recombinant RBD could bind to human ACE2 on the surface of HEK293A cells. Conclusion and implication: Our outcomes displayed that the recombinant RBD expressed in the E. coli strain has biological activity and can be used as an antigen for the development of diagnosis kits and vaccines as well as a tool for screening drugs against SASR-CoV-2.

Single-pericyte nanomechanics measured by contraction cytometry.

Pericytes line the microvasculature throughout the body and play a key role in regulating blood flow by constricting and dilating vessels. However, the biophysical mechanisms through which pericytes transduce microenvironmental chemical and mechanical cues to mediate vessel diameter, thereby impacting oxygen and nutrient delivery, remain largely unknown. This knowledge gap is clinically relevant as numerous diseases are associated with the aberrant contraction of pericytes, which are unusually susceptible to injury. Here, we report the development of a high-throughput hydrogel-based pericyte contraction cytometer that quantifies single-cell contraction forces from murine and human pericytes in different microvascular microenvironments and in the presence of competing vasoconstricting and vasodilating stimuli. We further show that murine pericyte survival in hypoxia is mediated by the mechanical microenvironment and that, paradoxically, pre-treating pericytes to reduce contraction increases hypoxic cell death. Moreover, using the contraction cytometer as a drug-screening tool, we found that cofilin-1 could be applied extracellularly to release murine pericytes from hypoxia-induced contractile rigor mortis and, therefore, may represent a novel approach for mitigating the long-lasting decrease in blood flow that occurs after hypoxic injury.

Drug evaluation platform based on non-destructive and real-time in situ organoid fate state monitoring by graphene field-effect transistor

3D organoid models have been widely used in drug evaluation because they effectively mimic physiological conditions and cell–cell interactions. However, current organoid-based drug evaluation heavily relies on invasive methods like qRT-PCR and immunofluorescence quantification, which disrupts the organoid’s structure and physiological function during the evaluation process. Therefore, it is urgent to develop a non-destructive drug evaluation platform to continuously monitor organoid fate. Here, a non-destructive and real-time in situ platform based on field effect transistor sensor (NDRS-FET) was developed to monitor organoid fate and obtained accurate drug evaluation by conducting the dynamic models. Using liver organoid as the model, the transition kinetics of liver organoid fate in response to candidate drug compounds were recorded by the NDRS-FET platform. OSM, FH1 and BG45 were successfully identified as effective regulators of liver organoid fate. Compared to traditional methods, the NDRS-FET platform could not only accurately capture the drug effect on organoid in real time, but also reduce the intergroup deviation among samples, providing more accurate and reliable tool for drug development and screening.

Comprehensive insight into 3D bioprinting technology for brain tumor modeling

Glioblastoma is one of the most common primary malignant brain tumors with a poor prognosis and high mortality rate. Because only small lipophilic molecules can penetrate the blood-brain barrier, chemotherapy and immunotherapy are limited in their ability to effectively treat brain tumor. Three-dimensional (3D) bioprinting has the potential to model the 3D environment of human pathology and diseases directly. In many cancers, 3D bioprinting technology closely mimics the tumor microenvironment, making it a promising tool for drug screening and uncovering the mechanisms of cancer initiation and progression. Recent 3D bioprinting technologies have been developed to recreate the dynamic interactions between the tumor and endothelial cells. Brain tumor models using 3D bioprinting technology can reconstruct the biophysical heterogeneity and immune interactions in the brain. These advanced models regulate the organization of tumor structures for preclinical drug testing and reveal the immunological pathways involved in brain tumor. Here, we highlight 3D bioprinting technologies that can replace conventional in vitro models for brain tumor treatment.

Unveiling Cellular Microenvironments with a Near-Infrared Fluorescent Sensor: A Dual-Edge Tool for Cancer Detection and Drug Screening.

Mitochondria and lysosomes are pivotal intracellular organelles, and the injury or dysfunction of these organelles can trigger a range of pathological processes. Early diagnosis and treatment of cancer are of paramount importance due to cancer's status as a leading health threat. This study introduces a novel fluorescent probe, BDHV, for detecting mitochondrial and lysosomal viscosity and pH abnormalities in tumors, facilitating early cancer detection and screening of anticancer drugs. Under acidic conditions, the red fluorescence of the probe gradually increases with increasing viscosity. Conversely, in alkaline environments, an increase in viscosity leads to a decrease in green fluorescence and an increase in red fluorescence. The inclusion of a benzothiazole group endows BDHV with strong dual-targeting capability for mitochondria and lysosomes and without being affected by the mitochondrial membrane potential. Most notably, BDHV has potential applications for early cancer diagnosis and in effectively assessing the efficacy of various anticancer drugs.

Predicting Clinical Outcomes of SARS-CoV-2 Drug Efficacy with a High-Throughput Human Airway Microphysiological System.

The average cost to bring a new drug from its initial discovery to a patient's bedside is estimated to surpass $2 billion and requires over a decade of research and development. There is a need for new drug screening technologies that can parse drug candidates with increased likelihood of clinical utility early in development in order to increase the cost-effectiveness of this pipeline. For example, during the COVID-19 pandemic, resources were rapidly mobilized to identify effective therapeutic treatments but many lead antiviral compounds failed to demonstrate efficacy when progressed to human trials. To address the lack of predictive preclinical drug screening tools, PREDICT96-ALI, a high-throughput (n = 96) microphysiological system (MPS) that recapitulates primary human tracheobronchial tissue,is adapted for the evaluation of differential antiviral efficacy of native SARS-CoV-2 variants of concern. Here, PREDICT96-ALI resolves both the differential viral kinetics between variants and the efficacy of antiviral compounds over a range of drug doses. PREDICT96-ALI is able to distinguish clinically efficacious antiviral therapies like remdesivir and nirmatrelvir from promising lead compounds that do not show clinical efficacy. Importantly, results from this proof-of-concept study track with known clinical outcomes, demonstrate the feasibility of this technology as a prognostic drug discovery tool.

Multi-omics and pharmacological characterization of patient-derived glioma cell lines

Glioblastoma (GBM) is the most common brain tumor and remains incurable. Primary GBM cultures are widely used tools for drug screening, but there is a lack of genomic and pharmacological characterization for these primary GBM cultures. Here, we collect 50 patient-derived glioma cell (PDGC) lines and characterize them by whole genome sequencing, RNA sequencing, and drug response screening. We identify three molecular subtypes among PDGCs: mesenchymal (MES), proneural (PN), and oxidative phosphorylation (OXPHOS). Drug response profiling reveals that PN subtype PDGCs are sensitive to tyrosine kinase inhibitors, whereas OXPHOS subtype PDGCs are sensitive to histone deacetylase inhibitors, oxidative phosphorylation inhibitors, and HMG-CoA reductase inhibitors. PN and OXPHOS subtype PDGCs stably form tumors in vivo upon intracranial transplantation into immunodeficient mice, whereas most MES subtype PDGCs fail to form tumors in vivo. In addition, PDGCs cultured by serum-free medium, especially long-passage PDGCs, carry MYC/MYCN amplification, which is rare in GBM patients. Our study provides a valuable resource for understanding primary glioma cell cultures and clinical translation and highlights the problems of serum-free PDGC culture systems that cannot be ignored.

PHCDTI: A multichannel parallel high-order feature crossover model for DTIs prediction

The exploration of non-covalent interactions between drugs and proteins (NCIs) has significantly improved the performance of drug–target interactions (DTIs) prediction models. However, existing methods for simulating NCIs are limited to single or multiple interactions, ignoring the combinatorial effects (i.e., high-order crossover between drugs and proteins (HOC-D&P)) that can arise when multiple NCIs coexist. To overcome this limitation, a multi-channel parallel high-order prediction model (PHCDTI) is proposed, aiming to simulate the complex interactions between drugs and proteins, thereby modeling HOC-D&P. Firstly, a tri-channel parallel model structure is constructed, allowing each channel to independently learn the interaction patterns between drug molecules and amino acid groups. Secondly, the three channels are designed from low-order to high-order, incorporating linear, inner-product, and pair-interaction feature crossover methods to simulate the complex interactions between drug molecules and amino acid groups. The stacking of residual connections enables the model to effectively model HOC-D&P. Additionally, by utilizing multi-head attention mechanisms for inner product and squeeze-excitation networks (SENET) for pair-interaction, the interpretability of the NCIs modeling process and the specific representation of drug molecules or amino acid groups are achieved. PHCDTI was evaluated on three benchmark datasets in four experimental settings, and the results indicated that it outperformed the most recent baseline model. In all cases, the average accuracy, precision, recall, AUC, and AUPR of PHCDTI are improved over the best baseline model by 3.56%, 6.06%, 3.99%, 2.50%, and 8.11%, respectively. Moreover, strong information filtering capabilities were exhibited by PHCDTI, with the effectiveness of the three-channel design confirmed by ablation studies. Finally, a case study on the human γ-aminobutyric acid receptors (GABARs) demonstrated that PHCDTI can serve as a powerful tool for real-world drug screening and design.

Advancements in Research and Treatment Applications of Patient-Derived Tumor Organoids in Colorectal Cancer.

Colorectal cancer (CRC) remains a significant health burden globally, being the second leading cause of cancer-related mortality. Despite significant therapeutic advancements, resistance to systemic antineoplastic agents remains an important obstacle, highlighting the need for innovative screening tools to tailor patient-specific treatment. This review explores the application of patient-derived tumor organoids (PDTOs), three-dimensional, self-organizing models derived from patient tumor samples, as screening tools for drug resistance in CRC. PDTOs offer unique advantages over traditional models by recapitulating the tumor architecture, cellular heterogeneity, and genomic landscape and are a valuable ex vivo predictive drug screening tool. This review provides an overview of the current literature surrounding the use of PDTOs as an instrument for predicting therapy responses in CRC. We also explore more complex models, such as co-cultures with important stromal cells, such as cancer-associated fibroblasts, and organ-on-a-chip models. Furthermore, we discuss the use of PDTOs for drug repurposing, offering a new approach to identify the existing drugs effective against drug-resistant CRC. Additionally, we explore how PDTOs serve as models to gain insights into drug resistance mechanisms, using newer techniques, such as single-cell RNA sequencing and CRISPR-Cas9 genome editing. Through this review, we aim to highlight the potential of PDTOs in advancing our understanding of predicting therapy responses, drug resistance, and biomarker identification in CRC management.

Advances in artificial cells based on microfluidic chips

One of the main goals of synthetic biology is to build artificial cells in a bottom-up manner, which not only facilitates the deep understanding of the origin of life and cell function but also plays a critical role in the research fields such as the development of artificial cell chassis, tissue models, engineering drug delivery systems, and drug screening tools. However, achieving this goal is extremely challenging. The complexity of cell structures and the miniaturization and diversity of basic modules pose high requirements for the construction methods. The microfluidic chip, as an advanced microanalysis system, serves as an effective tool for building artificial cells. It can accurately control the structure and local microenvironment of artificial cells, becoming the preferred approach for the current research on synthetic life. This article reviewed the methods of constructing, manipulating, and analyzed artificial cells based on microfluidic chips, emphasized the importance of the microenvironment for life systems and artificial self-sustaining systems. In addition, this article demonstrated the wide applications of artificial cells in multiple critical biomedical fields. Exploring the advantages, disadvantages, and application performance of different microfluidic methods can enrich our knowledge about artificial cell research. Finally, we made an outlook on the development of artificial cell research based on microfluidics, expecting that this field can achieve greater breakthroughs and progress.

Development and validation of Mayaro virus with luciferase reporter genes as a tool for antiviral assays

Arboviruses are etiological agents in an extensive group of emerging diseases with great clinical relevance in Brazil, due to the wide distribution of their vectors and the favorable environmental conditions. Among them, the Mayaro virus (MAYV) has drawn attention since its emergence as the etiologic agent of Mayaro fever, a highly debilitating disease. To study viral replication and identify new drug candidates, traditional antiviral assays based on viral antigens and/or plaque assays have been demonstrating low throughput, making it difficult to carry out larger-scale assays. Therefore, we developed and characterized two DNA-launched infectious clones reporter viruses based on the MAYV strain BeAr 20290 containing the reporter genes of firefly luciferase (FLuc) and nanoluciferase (NLuc), designated as MAYV-firefly and MAYV-nanoluc, respectively. The viruses replicated efficiently with similar properties to the parental wild-type MAYV, and luminescence expression levels reflected viral replication. Reporter genes were also preserved during passage in cell culture, remaining stably expressed for one round of passage for MAYV-firefly and three rounds for MAYV-nanoluc. Employing the infectious clone, we described the effect of Rimantadine, an FDA-approved Alzheimer's drug, as a repurposing agent for MAYV but with a broad-spectrum activity against Zika virus infection. Additionally, we validated MAYV-nanoluc as a tool for antiviral drug screening using the compound EIDD-2749 (4′-Fluorouridine), which acts as an inhibitor of alphavirus RNA-dependent RNA polymerase.

Physical parametric study of bacterial biofilm disruption and removal by jet impingement: A CFD investigation

Bacterial biofilm formation is one of the most critical challenges in industrial and health systems. It is the leading cause of nearly 80 % of clinical infections. Biofilms are usually evaluated from the physiological point of view as microbial cells enclosed in an extracellular polymer and represent a complex, dynamic bacterial community. Cohesive mechanical forces hold the bacteria within the biofilm together. These forces contribute to the biofilm's mechanical and structural stability, resulting in its viscoelastic properties. Studying the biofilm's mechanical properties as a viscoelastic matter can provide a better understanding of the biofilm's characteristics and the survival strategies of bacteria in the biofilm state of life. In the present study, a 2D-axisymmetric RANS-CFD simulation model using the Volume Of Fluid (VOF) method was developed to track changes in biofilm surface and ripple formation across six biofilm thicknesses ranging from 15 μm to 115 μm, two substrate geometries including flat and curved, and two substrate roughnesses of 0.4 μm and 0.9 μm height. A modified Herschel-Bulkley model was employed to capture the biofilm's non-Newtonian shear-thinning behavior under high-velocity gas jet impingement. The results revealed the importance of biofilm thickness, substrate geometries, and properties like roughness in biofilm's mechanical behavior. Higher thickness of biofilm resulted in smaller jet-impingement region and more significant ripples formation. Biofilm on curved substrates decreased in thickness more rapidly than those on flat substrates. The substrate's geometry impacted biofilm folding patterns, removal, and mechanical behavior. Selected substrate roughnesses did not create any resistance against the mechanical removal of biofilms. Here, we successfully captured biofilms' non-Newtonian and shear-thinning behavior with numerical simulations consistent with previously reported experimental results. This could benefit industrial and health systems by tackling biofilm-related challenges and developing more accurate and detailed models of biofilms to optimize tools for drug testing or screening and enhance the models for in-vitro and in-vivo analysis.

Rational construction of a novel fluorescent probe for imaging peroxynitrite in the endoplasmic reticulum during drug-induced liver injury

Drug-induced liver injury (DILI) not only poses a serious health threat to patients, but is also a major obstacle to the development of new drugs. The liver toxicity of many drugs is not detected until late in the development process or even after marketing, which significantly increases the cost of new drug development. This may be limited by the lack of tools to detect DILI. Studies have shown that abnormal changes in peroxynitrite (ONOO-) levels in the endoplasmic reticulum of liver cells may be an early manifestation of DILI. Therefore, the development of fluorescent probes to detect ONOO- in the endoplasmic reticulum may provide assistance in the detection of DILI and the screening of new drugs. Herein, we report a fluorescent probe, ER-N, capable of detecting ONOO- in the endoplasmic reticulum with high selectivity and sensitivity. The probe selects di(trifluoromethyl)benzene as the targeting group of the endoplasmic reticulum, which possesses excellent targeting to the endoplasmic reticulum, and provides a new design method for the establishment of other endoplasmic reticulum-targeting probes. In addition, the probe ER-N successfully realized the detection of endogenous and exogenous ONOO- in cells and zebrafish. More importantly, the probe ER-N was able to be used for tracing changes in the levels of ONOO- in the endoplasmic reticulum of cells and tissues under drug stimulation. Together, these results suggest that the probe ER-N has the potential to be a tool for DILI detection and new drug screening.

Novel organoid platform for drug screening of patients with breast cancer.

e13125 Background: Marketed methods are available for in vitro organoid growth for the purpose of translational science, evaluation of drug efficacy and patient treatment predictivity, but require needle biopsy of the tumor which is invasive to the patient. Non-invasive methods exist for isolating circulating tumor cells (CTC) from blood but require large volumes due to their low frequency (<1 in 105-106 PBMCs). Low CTC recovery limits the number of downstream analyses. To overcome these obstacles, Cellentia is introducing a novel in vitro system called R3CE (Rapid, Reproducible, Rare Cell Expansion), developed by AcroCyte Therapeutics Inc. (Taiwan), to the US market. The advantage of R3CE is that blood is used to generate viable representative cells of the patient’s tumor which can be expanded and banked, thus the number of characterization assays is flexible. The R3CE method allows for extensive drug screening within a rapid timeframe to inform patient treatment. This poster will show drug screening results on organoids derived from blood of breast cancer patients, and R3CE method transfer to Cellentia. Methods: For patient drug screening, 0.5 mL of peripheral blood was drawn from stage IV breast cancer patients. Cells were seeded onto proprietary plates, cultured for several days, passaged and screened for drug resistance or susceptibility to Cisplatin, Paclitaxel, 5-FU, Vinorelbine, and Gemcitabine by assessing the relative viability from luminescent measurements of drug treated organoids normalized to a mock control. For R3CE method transfer, frozen breast cancer organoids were thawed and seeded onto proprietary plates, grown for several days and used in the drug screen as described above. Results: Blood from five breast cancer patients (Patients A-E) were grown into organoids and used for screening drugs listed (Table). Relative viabilities were calculated. A threshold was set at 10% where relative viabilities above or below 10% showed the organoids were resistant (R) or susceptible (S) to killing by the drug candidate, respectively. The results of the R3CE drug test were compared to the clinical (Clin) outcome for each patient (clinical outcome is unknown (U) in some instances) and shown (Table). The drug test and the clinical outcome showed 100% concordance. Cellentia executed drug screening with the same drug panel utilizing frozen breast cancer organoids in the R3CE platform and demonstrated susceptibility in the drug screening. Conclusions: R3CE platform showed promising results as a personalized drug screening tool for breast cancer patients. Frozen breast cancer organoids for drug screening demonstrated successful method transfer to Cellentia. [Table: see text]

From land to water: “Sunken” T-maze for associated learning in cichlid fish

The study introduced and evaluated learning paradigms for Maylandia callainos cichlids using a modified version of the rodent T-maze, filled with tank water (the "sunken" modification). Both male and female fish underwent training in two distinct conditioning paradigms. Firstly, simple operant conditioning involved placing a food reward in either the right or left compartment. Cichlids demonstrated the ability to purposefully find the bait within 6 days of training, with a persistent place preference lasting up to 6 days. Additionally, the learning dynamics varied with sex: female cichlids exhibited reduction in latency to visit the target compartment and consume the bait, along with a decrease in the number of errors 3 and 4 days earlier than males, respectively. Secondly, visually-cued operant conditioning was conducted, with a food reward exclusively placed in the yellow compartment, randomly positioned on the left or right side of the maze during each training session. Visual learning persisted for 10 days until reaction time improvement plateaued. Color preference disappeared after 4 consecutive check-ups, with no sex-related interference. For further validation of visually-cued operant conditioning paradigm, drugs MK-801 (dizocilpine) and caffeine, known to affect performance in learning tasks, were administered intraperitoneally. Chronic MK-801 (0.17 mg/kg) impaired maze learning, resulting in no color preference development. Conversely, caffeine administration enhanced test performance, increasing precision in fish. This developed paradigm offers a viable approach for studying learning and memory and presents an effective alternative to rodent-based drug screening tools, exhibiting good face and predictive validity.

Generation of Alzheimer's Disease Model Derived from Induced Pluripotent Stem Cells with APP Gene Mutation.

Alzheimer's disease (AD), the most common cause of dementia, is characterized by disruptions in memory, cognition, and personality, significantly impacting morbidity and mortality rates among older adults. However, the exact pathophysiological mechanism of AD remains unknown, and effective treatment options for AD are still lacking. Human induced pluripotent stem cells (iPSC) are emerging as promising platforms for disease research, offering the ability to model the genetic mutations associated with various conditions. Patient-derived iPSCs are useful for modeling neurodegenerative and neurodevelopmental disorders. In this study, we generated AD iPSCs from peripheral blood mononuclear cells obtained from a 65-year-old patient with AD carrying the E682K mutation in the gene encoding the amyloid precursor protein. Cerebral organoids derived from AD iPSCs recapitulated the AD phenotype, exhibiting significantly increased levels of tau protein. Our analysis revealed that an iPSC disease model of AD is a valuable assessment tool for pathophysiological research and drug screening.

AlveoMPU: Bridging the Gap in Lung Model Interactions Using a Novel Alveolar Bilayer Film.

The alveoli, critical sites for gas exchange in the lungs, comprise alveolar epithelial cells and pulmonary capillary endothelial cells. Traditional experimental models rely on porous polyethylene terephthalate or polycarbonate membranes, which restrict direct cell-to-cell contact. To address this limitation, we developed AlveoMPU, a new foam-based mortar-like polyurethane-formed alveolar model that facilitates direct cell-cell interactions. AlveoMPU features a unique anisotropic mortar-shaped configuration with larger pores at the top and smaller pores at the bottom, allowing the alveolar epithelial cells to gradually extend toward the bottom. The underside of the film is remarkably thin, enabling seeded pulmonary microvascular endothelial cells to interact with alveolar epithelial cells. Using AlveoMPU, it is possible to construct a bilayer structure mimicking the alveoli, potentially serving as a model that accurately simulates the actual alveoli. This innovative model can be utilized as a drug-screening tool for measuring transepithelial electrical resistance, assessing substance permeability, observing cytokine secretion during inflammation, and evaluating drug efficacy and pharmacokinetics.

In Situ Self-Assembling Liver Spheroids with Synthetic Nanoscaffolds for Preclinical Drug Screening Applications.

Drug-induced liver injury (DILI) is one of the most common reasons for acute liver failure and a major reason for the withdrawal of medications from the market. There is a growing need for advanced in vitro liver models that can effectively recapitulate hepatic function, offering a robust platform for preclinical drug screening applications. Here, we explore the potential of self-assembling liver spheroids in the presence of electrospun and cryomilled poly(caprolactone) (PCL) nanoscaffolds for use as a new preclinical drug screening tool. This study investigated the extent to which nanoscaffold concentration may have on spheroid size and viability and liver-specific biofunctionality. The efficacy of our model was further validated using a comprehensive dose-dependent acetaminophen toxicity protocol. Our findings show the strong potential of PCL-based nanoscaffolds to facilitate in situ self-assembly of liver spheroids with sizes under 350 μm. The presence of the PCL-based nanoscaffolds (0.005 and 0.01% w/v) improved spheroid viability and the secretion of critical liver-specific biomarkers, namely, albumin and urea. Liver spheroids with nanoscaffolds showed improved drug-metabolizing enzyme activity and greater sensitivity to acetaminophen compared to two-dimensional monolayer cultures and scaffold-free liver spheroids. These promising findings highlight the potential of our nanoscaffold-based liver spheroids as an in vitro liver model for drug-induced hepatotoxicity and drug screening.

Organoids as a new approach for improving pediatric cancer research.

A key challenge in cancer research is the meticulous development of models that faithfully emulates the intricacies of the patient scenario, with emphasis on preserving intra-tumoral heterogeneity and the dynamic milieu of the tumor microenvironment (TME). Organoids emerge as promising tool in new drug development, drug screening and precision medicine. Despite advances in the diagnoses and treatment of pediatric cancers, certain tumor subtypes persist in yielding unfavorable prognoses. Moreover, the prognosis for a significant portion of children experiencing disease relapse is dismal. To improve pediatric outcome many groups are focusing on the development of precision medicine approach. In this review, we summarize the current knowledge about using organoid system as model in preclinical and clinical solid-pediatric cancer. Since organoids retain the pivotal characteristics of primary parent tumors, they exert great potential in discovering novel tumor biomarkers, exploring drug-resistance mechanism and predicting tumor responses to chemotherapy, targeted therapy and immunotherapies. We also examine both the potential opportunities and existing challenges inherent organoids, hoping to point out the direction for future organoid development.