From:  Engineering the microenvironment: advanced biomaterials for humanized in vitro immunotoxicology and carcinogenicity assessment

 Comparative analysis of models for toxicology and carcinogenicity assessment.

FeatureTraditional 2D culturesAnimal modelsAdvanced 3D biomaterial-based humanized models
Physiological relevanceLow: lacks tissue architecture, ECM, gradients, and complex cell-cell interactions.Moderate: has systemic physiology but suffers from critical species-specific differences.High: precisely engineered ECM, 3D architecture, co-cultures, and physiological gradients mimic human tissue niches.
Predictive power for human responsePoor: high false positive/negative rates due to altered cell states.Variable: often poor, as evidenced by > 90% clinical attrition rate for drugs safe in animals.Superior: human-derived cells in a human-like microenvironment yield more clinically translatable data on efficacy and toxicity.
Immunological relevanceLimited: cannot model complex human immune responses (e.g., TDAR).Limited: fundamental differences in immune system function and antigen presentation.High: enables co-culture of human immune and tissue-specific cells to model immunotoxicity, cytokine release, and immunotherapy efficacy.
Throughput & costHigh: cheap, scalable, amenable to HTS.Very low: extremely costly, time-consuming, low-throughput.Moderate-improving: higher cost than 2D, but throughput is increasing with automation and standardized biomaterial platforms.
Ethical considerationsLow concern.Major concern: significant ethical burden and regulatory push for reduction (3Rs).Low concern: human-centric, reduces reliance on animal testing.
Personalization potentialLimited: primarily uses immortalized cell lines.None: Uses genetically homogeneous animal cohorts.High: patient-derived cells [e.g., patient-derived organoids (PDOs)] can be used to create personalized avatars for drug screening.
Key limitationOver-simplification leads to poor predictability.Species differences lead to poor predictability and ethical issues.Standardization, characterization, and integration into regulatory workflows are ongoing challenges.