Organoids: a revolution in in vitro mammalian cell culture
In this post, learn more about the challenges in developing organoids and resources available to overcome them.
The development of organoid culture systems for a variety of tissues has been one of the most exciting advances in stem cell research of the past decade. Following the landmark studies on intestinal epithelial organoid culture(1), multiple protocols have been developed to derive organoids across a wide range of species and tissues from both adult tissue and pluripotent stem cells(2–5). While each system is distinct, generally these 3D culture systems feature a self-renewing stem cell population that differentiates into multiple, organ-specific cell types. The ability to culture these organoids in vitro provides specific benefits such as greater physiological relevance when compared to primary cell lines and removal of confounding factors inherent in animal models.
The continued development of organoid methodologies is proving transformative to the stem cell research landscape. The refinement of organoid culture techniques has made possible the ex vivo maintenance and expansion of genetically normal adult stem cell populations specific to unique organs. Due to subtle differences in culture techniques, the characteristics of organoid cultures can vary according to the organ of origin and the specific culture method.
However, in general organoid cultures retain key features of the associated tissue as well as of the individual animal, tissue state and disease phenotype of the originating sample. These functionalities make organoid cultures a valuable research platform for a diverse range of researchers with equally diverse research aims and challenges.
The Present and the Promise of Organoid Use
Organoid cultures have seen quick and widespread adoption in a variety of applications from basic research to more clinical applications. The adoption of organoid methodologies has complimented and advanced studies previously performed using model animals in the laboratories of many cell biologists, opening new avenues of experimental inquiry. In addition, organoids are being utilized to determine patient-specific drug responses to cystic fibrosis therapies in a government-supported screening program(6). Likewise, the concentration of studies surrounding the 2015 outbreak of the Zika virus saw sweeping application of the cerebral organoid methodology to study virus-associated microcephaly(7).
The avenues of expanded or accelerated discovery that have been opened by the development of organoid culture protocols are also subject to many remaining challenges and limitations within the fields adopting these cutting-edge techniques. Despite the promise provided, organoid culture protocols still face a number of obstacles for widespread adoption, including the standardization of tools and techniques used in their manipulation.
At its core, this process entails publication of proof-of-concept studies and pilot applications of organoid cultures in a specific scientific context leading to wider adoption of organoid technologies by other researchers in the same field. Such studies also serve to inform the experimental design of research performed using these organoids in order to further refine the experimental conditions for the application of organoids within that context. Practical considerations for mass adoption of organoid culture systems also remain(8). Challenges ranging from inconsistencies in nomenclature to variation in the specific methodologies and medium compositions used across different institutions, or even individual labs within an institution, complicate the widespread adoption of organoid techniques.
By virtue of the nature of their spontaneous cellular organization and differentiation, organoid cultures exhibit significant inherent variability. When compounded with even modest modifications to culture protocols and growth factor identities or concentrations in the cell culture media, this variability can make direct data comparison between groups challenging.
Organoid Tools and Resources
Incorporating organoid cultures within a given research program can be a valuable way to expand the types of specific research questions that can be effectively answered within that lab. Greater standardization of organoid techniques within an individual field could significantly increase the rate of discovery within that field, but only if labs can collaborate effectively by generating compatible data. One important variable supporting greater collaboration is the availability of standardized and rigorously quality-controlled cell culture medium for organoid cultures.
Through exclusive partnerships with the Institute of Molecular Biotechnology (Vienna, Austria) and the Foundation Hubrecht Organoid Technology (the Netherlands), STEMCELL Technologies Inc. (BC, Canada) has committed to providing researchers in widely disparate fields with the tools they need to seamlessly integrate organoid cultures into their experimental repertoires. To support this effort, STEMCELL has also assembled collections of informational resources for organoid cultures including publications categorized by research field, researcher interviews and profiles, and technical documentation. The development of robust products for organoid culture, including optimized media and protocols, and the increasing dissemination of organoid knowledge serves to drive the standardization of organoid techniques.
STEMCELL has a growing portfolio of complete media with accompanying step-by-step protocols to make adopting or streamlining organoid cultures a straight-forward proposition. IntestiCult™ Organoid Growth Medium for either mouse or human support establishment and long-term passaging of intestinal epithelial organoid cultures from fresh biological samples or previously frozen organoid lines.
The STEMdiff™ Cerebral Organoid Kit provides the necessary reagents and protocols for generating human cerebral organoids from pluripotent stem cells that can be matured over weeks or months in culture. HepatiCult™ Organoid Growth Medium (Mouse)and PancreaCult™ Organoid Growth Medium (Mouse) enable establishment and rapid expansion of mouse hepatic progenitor organoids and pancreatic exocrine organoids, respectively. This group of available tools will continue to grow with the introduction of optimized media for both pluripotent and adult stem cell-derived organoids spanning tissue types and applications.
- Sato T, Vries RG, Snippert HJ et al. Single Lgr5 stem cells build crypt-villus structures in vitro without a mesenchymal niche. Nature. 459(7244): 262–5 (2009)
- Lancaster MA, Knoblich JA. Organogenesis in a dish: Modeling development and disease using organoid technologies. Science. 345(6194): 1247125 (2014)
- Huch M, Koo B-K. Modeling mouse and human development using organoid cultures. Development. 142(18): 3113–25 (2015)
- Kretzschmar K, Clevers H. Organoids: Modeling development and the stem cell niche in a dish. Dev. Cell. 38(6): 590–600 (2016).
- Clevers H. Modeling development and disease with organoids. Cell. 165(7): 1586–97 (2016)
- Hagemeijer MG, Siegwart DJ, Strug LJ et al. Translational research to enable personalized treatment of cystic fibrosis. J Cyst Fibros. Dec 21 (2017)
- Lancaster MA, Renner M, Martin C-A et al. Cerebral organoids model human brain development and microcephaly. Nature. 501(7467): 373-9 (2013)
- Spence JR. Taming the Wild West of Organoids, Enteroids, and Mini-Guts. Cell Mol Gastroenterol Hepatol. 5(2)5:159–160 (2018)