A
ADME
Absorption, Distribution, Metabolism, and Excretion. The four processes that determine a drug's pharmacokinetics—how the body handles a drug from administration to elimination.
Assembloid
A fusion of two or more organoid types that models organ-organ interactions. Example: cortico-striatal assembloids combine cortical and striatal brain organoids to study neural circuit formation.
B
Body-on-Chip / Human-on-Chip
A multi-organ microphysiological system connecting multiple organ chips (e.g., liver, heart, kidney, lung) to model systemic drug effects and organ-organ interactions.
BBB (Blood-Brain Barrier)
The selective barrier separating circulating blood from brain tissue. BBB-on-chip models are critical for CNS drug development, as 98% of small molecules cannot cross this barrier.
C
CYP450 Enzymes
Cytochrome P450 enzymes responsible for metabolizing most drugs. Key isoforms include CYP3A4 (metabolizes ~50% of drugs), CYP2D6, CYP2C9, and CYP1A2. Liver-on-chip must express these for valid ADME studies.
CiPA (Comprehensive in vitro Proarrhythmia Assay)
FDA initiative to evaluate cardiac safety using human iPSC-derived cardiomyocytes. Part of "Clinical Trials in a Dish" approach to replace animal cardiotoxicity studies.
D
Digital Twin
A virtual representation of a patient's biological system that simulates physiological responses. Can model individual organs, systems, or whole-body physiology for treatment optimization and drug development.
DILI (Drug-Induced Liver Injury)
Liver damage caused by medications. Responsible for ~20% of acute liver failure cases and numerous drug withdrawals. Primary application for liver-on-chip technology.
F
FDA Modernization Act 2.0
Legislation signed December 29, 2022 eliminating the 86-year mandate for animal testing in drug development. Authorizes cell-based assays, organ chips, microphysiological systems, and computer models as valid alternatives.
FDA Modernization Act 3.0
Follow-on legislation (Senate passed December 16, 2025) mandating replacement of "animal" with "nonclinical" throughout Title 21 CFR within one year of enactment.
I
iPSC (Induced Pluripotent Stem Cells)
Adult cells reprogrammed to an embryonic-like pluripotent state, capable of differentiating into any cell type. Enables patient-specific disease modeling and drug testing without embryonic tissue.
ISTAND (Innovative Science and Technology Approaches for New Drugs)
FDA pilot program under 21st Century Cures Act for qualifying novel drug development tools. Emulate's Liver-Chip S1 received first ISTAND acceptance for organ-on-chip (September 2024).
IND (Investigational New Drug)
FDA application required before human clinical trials can begin. Alternative testing data (organoids, organ-on-chip) can now support IND applications under FDA Modernization Act 2.0.
M
MPS (Microphysiological Systems)
Umbrella term for organ-on-chip devices and related microfluidic cell culture platforms that recreate human organ physiology. Often used interchangeably with "organ-on-chip."
Microfluidics
Technology for manipulating small volumes of fluids in channels with dimensions of tens to hundreds of micrometers. The foundation of organ-on-chip devices, enabling controlled cell culture environments.
N
NAMs (New Approach Methodologies)
Any non-animal technology, methodology, approach, or combination thereof that can provide information on chemical hazard and risk assessment. Includes in vitro assays, organ-on-chip, organoids, computational models, and "-omics" technologies.
NCATS (National Center for Advancing Translational Sciences)
NIH institute funding the Tissue Chip for Drug Screening program. Has invested $150M+ since 2012 in microphysiological systems development.
O
Organ-on-Chip (OoC)
A microfluidic cell culture device containing living human cells arranged to simulate tissue- and organ-level physiology. The chip recreates mechanical forces, fluid flow, and tissue interfaces found in the human body.
Organoid
A three-dimensional, self-organizing tissue culture derived from stem cells that recapitulates the architecture and function of a human organ. First developed by Hans Clevers in 2009 (intestinal organoids).
P
Patient Analog
Any technology that simulates human biology for drug development purposes, replacing or augmenting animal testing. The category encompasses organoids, organ-on-chip, digital twins, and AI-powered predictive models.
PBPK (Physiologically Based Pharmacokinetic) Modeling
Computational models that simulate drug absorption, distribution, metabolism, and excretion based on physiological parameters. Established regulatory acceptance for dose optimization.
PDTO (Patient-Derived Tumor Organoid)
Tumor organoid grown from an individual patient's cancer tissue. Maintains genetic and phenotypic features of the original tumor for personalized drug sensitivity testing.
Q
QSP (Quantitative Systems Pharmacology)
Computational modeling approach that integrates drug pharmacology with disease biology. Uses mathematical models to predict drug effects at the systems level.
T
3Rs (Replacement, Reduction, Refinement)
Ethical framework for animal research: Replace animals with alternatives where possible, Reduce the number of animals used, and Refine procedures to minimize suffering. Originated by Russell and Burch (1959).
Tissue Chip
NIH/NCATS term for organ-on-chip devices. The "Tissue Chip for Drug Screening" program has invested $150M+ in MPS development since 2012.