The liver plays a central role throughout drug discovery, nonclinical development, and clinical translation. Its importance extends far beyond toxicity. As a major site of drug metabolism and bioactivation, the liver can contribute to influence drug efficacy and safety through metabolism-dependent effects, contribute to species-specific responses, and shape the exposure of other organs to parent compounds and their metabolites.
Access to a physiologically relevant in vitro liver model can therefore help researchers better recapitulate key aspects of liver biology, interpret nonclinical findings, and make more informed decisions when selecting candidates for clinical development. 3D InSight™ Liver Microtissues combine primary, species-specific hepatocytes with non-parenchymal cells in a defined 3D co-culture. Available in Assay-Ready formats, they allow researchers to introduce a standardized, quality-controlled liver model directly into existing workflows without having to establish, optimize, and qualify the model internally.
From early safety signals to deeper mechanistic insights
Identifying liver toxicity is important, but understanding why it occurs can be even more valuable for compound progression and decision-making. This requires a model that not only detects hepatocyte damage, but also maintains the relevant biological functions needed to investigate underlying mechanisms of adverse effects.
3D InSight™ Liver Microtissues remain viable and functional for up to 28 days, maintaining key liver characteristics including albumin production, metabolic competence, hepatocyte polarization, and bile canaliculi formation. 3D InSight™ Human Liver Microtissues are generated using primary human hepatocytes from a 10-donor pool, incorporating inter-donor biological diversity within a standardized experimental model. The inclusion of non-parenchymal cells further extends the biological relevance of the system. Kupffer cells, for example, enable researchers to investigate the contribution of immune-mediated mechanisms to drug-induced liver injury.
Together, these characteristics support both repeated-exposure studies and deeper mechanistic investigation. Biochemical and transcriptomic endpoints can be used to investigate pathways associated with reactive metabolite formation, oxidative stress, steatosis, hepatocellular injury, cholestasis, mitochondrial dysfunction, and innate immune activation.
At the same time, availability in 96- and 384-well formats allows the model to be applied across workflows from compound screening through lead optimization. Standardized production, regular availability, and consistent primary cell lots further support reproducibility across plates, production runs, and longer-term discovery programs.
Bridging species: putting preclinical findings into human context
Animal studies remain an important component of nonclinical development, providing information on target-organ toxicity, dose response, reversibility, and safety margins. However, differences in drug metabolism, transport, and molecular targets between species can make it difficult to determine whether an animal safety signal is relevant to humans.
3D InSight™ Species-specific 3D Liver Microtissues provide a physiologically relevant platform to investigate these differences under controlled and comparable experimental conditions, contributing to mechanistic and human-relevance assessment. This cross-species approach can also support the transition toward greater use of New Approach Methodologies (NAMs) in nonclinical development. In line with the FDA Modernization Act 2.0 and subsequent FDA initiatives to reduce reliance on animal testing, robust and reproducible in vitro models can contribute to the 3Rs – Replacement, Reduction, and Refinement. Animal-derived NAMs can provide an important bridge in this transition: comparison of in vitro responses with existing in vivo findings from the same species can help establish confidence in model performance before extending the approach to human-relevance assessment.
By performing aligned studies in human and preclinical species, researchers can address an important translational question: Is an observed toxicity driven by a species-specific mechanism, or does the underlying mechanism appear relevant to humans?
The development of amcenestrant provides one example. Cholestatic liver injury observed in dogs, but not rats, raised questions about potential human relevance. Comparative studies using rat, dog, and human liver microtissues supported a dog-specific mechanism involving antagonism of the Farnesoid X Receptor (FXR) by amcenestrant and its M5 metabolite. The same response was not observed in rat or human microtissues, helping place the in vivo dog finding into mechanistic and human-relevant context.
Assay-Ready 3D InSightTM Species-Specific Liver Microtissues are available from C57BL/6 mouse, and Beagle dog, enabling cross-species screening and mechanistic studies using closely aligned experimental conditions. Sprague Dawley rat and Cynomolgus monkey liver microtissues are also available through InSphero’s Translational Toxicology Services, further expanding the range of preclinical species that can be compared with human models.
Read our white paper here: https://insphero.com/resource/utilizing-cross-species-in-vitro-models/
Watch the webinar: https://insphero.com/service/translational-toxicology-service/
Extend liver studies to multi-organ biology
A parent drug may be well tolerated by another organ while a metabolite generated by the liver introduces toxicity. Conversely, hepatic metabolism may reduce toxicity, modify exposure, or change the efficacy of the parent compound. When multiple drugs are administered together, drug–drug interactions can further alter metabolism and downstream responses.
Understanding these relationships can therefore be important when evaluating drug safety and efficacy.
Because 3D InSight™ Liver Microtissues maintain metabolic competence over extended culture periods, they can be combined with other organ models or incorporated as the metabolically active component of multi-organ systems. Published applications include liver–brain models investigating metabolism-dependent neurotoxicity and multi-tissue systems studying metabolism-related drug–drug interactions.
The same principle could be applied to other questions, for example by combining liver and cardiac models to investigate whether liver-generated metabolites introduce cardiotoxicity that would not be detected when testing the parent compound on cardiac tissue alone.
Multi-organ approaches can also address efficacy questions—for example, by determining whether hepatic metabolism activates or inactivates a therapeutic before it reaches the target tissue.
Go Beyond Conventional Liver Safety
The physiological relevance, long-term stability, and scalability of 3D InSight™ Liver Microtissues make them useful for applications extending beyond conventional drug-induced liver injury assessment.
In infectious disease research and antiviral drug testing, 3D InSight™ Liver Microtissues can support investigation of viral replication, virus-induced cytopathology, and therapeutic efficacy. In environmental toxicology, they provide a human-relevant system for investigating contaminants such as PFAS, supporting potency ranking, mode-of-action studies, and transcriptomic characterization.
3D InSight™ Liver Microtissues are also being applied in regenerative medicine and cell therapy research, where they can provide a physiologically relevant tissue environment for studying therapeutic-cell interactions, adhesion, and engraftment. Their metabolic competence can additionally support efficacy and safety assessment of new therapeutic modalities in oncology research.
Together, these applications demonstrate how a well-characterized 3D liver model can serve as a versatile experimental platform for multiple questions across drug discovery and translational research.
Bring Advanced Liver Biology Into Your Lab
Physiologically relevant 3D in vitro models can provide valuable biological insight, but establishing them internally requires time, specialist expertise, and resources for cell sourcing, aggregation, optimization, validation, and quality control.
Assay-ready 3D InSight™ Liver Microtissues reduce this operational burden by providing pre-aggregated, quality-controlled microtissues directly in automation-compatible Akura™ 96- or 384-well Spheroid Microplates.
Standardized production supports consistency in microtissue size, viability, functionality, and performance across wells, plates, and production batches. This is particularly important for compound screening, repeated-dose experiments, and longer-term studies in which consistent comparison across experiments is essential.
For research teams, assay readiness is therefore more than convenience. It provides a practical way to introduce advanced liver biology into established workflows while reducing model-development complexity.
Researchers can spend less time building and qualifying the model – and more time designing studies, testing compounds, analyzing data, and making drug discovery decisions.
