Organoids refer to 3D cultures of different cell types derived from tissue explants, tumors, stem cells, or other progenitor cells that self-organize and differentiate into functional cell types under controlled conditions to obtain information about the complexity, anatomy, and physiology of an organ or body structure.
1. Preservation of organoid characteristics
The main advantages of organoids over standard cell culture methods are the 3D spatial arrangement of cultured cells, mimicking their natural morphology, and the organoids retain the cellular and molecular mechanisms of the cell.
2. Cell-cell and cell-matrix interactions
Organoids allow for interaction between multiple cell types and resemble organ-like complex structures that are not possible with any standard monolayer culture, spheroid, or even co-culture of two or more cell types. Organoids offer the opportunity to study cell-ECM interactions and cell-to-cell interactions at a 3D level.
3. Individual-level modeling
Organoids are generated from individual individuals or patients to provide cellular, morphological, and other scientific data at the individual level.
4. High-throughput and efficient preclinical models
Compared to spheroids or standard cell cultures, organoids are more similar to in vivo systems and can be effectively used to model disease mechanisms and test the efficacy of drug candidates and other disease** interventions.
Drug discovery
Organoids are a fast and reliable method for drug toxicity testing, drug discovery, screening, and validation. Toxicity of 238 marketed drugs in liver organoids, 25 cardioactive drugs in cardiac organoids, cisplatin and gentamicin in renal organoids, 39 commercially available diarrhea-causing drugs in intestinal organoids, and vincristine and rotenone in brain organoids have been tested and reported.
Disease modeling
Human iPSC-based organoids are sensitive to pathogens and provide potential ways to mimic host-pathogen interactions during bacterial or viral infection. Brain and neural organoids have been used to mimic Zika virus infection. Intestinal organoids have successfully mimicked rotavirus pathology, and gastric organoids have been used to mimic bacterial infection with Helicobacter pylori. Lung organoids from human PSC** reveal various aspects of SARS-CoV-2 infection, including cytotropism, how genetic characteristics affect susceptibility to viral infection, the mechanisms by which the virus enters and replicates in the host, host cell responses, and changes in cells and metabolic infection.
Developmental Biology
Organoids can be used to simulate morphogenetic events to provide detailed insight into the development and function of tissues and organs. Organoids composed of mouse and human ESCs undergo self-organization and gastrulation embryogenesis in culture, providing new insights into early mammalian development. In addition, organoids provide a model system to study mechanisms of self-organization under different conditions, increasing our understanding of self-organization and in vitro control of complex multicellular behaviors.
Personalized medicine
Organoids are the best model for studying human-to-human differences in disease pathogenesis, individual responses to disease, and helping to tailor to individual needs. Organoids offer the potential to study a variety of shared or unique mechanisms in organ development and function, disease progression, or infection allergies, which may differ from those involved in immortalized cell lines or animal models.