Tiny, lab-grown ‘organoids’ have huge potential
Among the many innovations happening in biomedical research today, one of the most exciting is our ability to study “organs in a dish.” Called organoids, these three-dimensional structures grown in a laboratory culture dish enable a wide array of research studies heretofore impossible.
Organoids are small, sesame seed-size clusters of living cells that resemble tissues and organs when examined under a microscope. They are grown under precise conditions in a laboratory dish containing a nutrient-rich liquid and can be sustained for weeks or months at a time.
About 10 years ago, we began to understand how organoids might be grown. Before that, the crucial scientific knowledge simply was not there. Based on insights from the study of stem cells — the highly specialized cells in our bodies with the unique ability to replicate and give rise to all other cells — scientists began to grow organoids for the first time.
Organoids have now been developed from many types of human cells including brain, liver, intestine, kidney, pancreas, breast and others. Catchy names have been developed like mini-brains, mini-guts, mini-organs and “organs in a dish.”
Based on decades of previous research, the nutrients and conditions to grow each of these are now defined by highly sophisticated and unique recipes. Not surprisingly, the recipe to grow a mini-brain does not work for a mini-gut.
Organoids are enormously powerful tools for understanding human disease. The effects of drugs can be tested on organoids to discover new therapies for diseases such as cystic fibrosis and cancer. Within the past year, our understanding of brain diseases such as autism, epilepsy and Alzheimer’s disease has been advanced based on the study of minibrains. The devastating effects of the Zika virus on brain development is now better understood based on organoid research.
There is also excitement about the potential to use organoids as a treatment for diseases such as Type 1 diabetes and many genetic disorders. Scientists believe stems cells can be isolated from affected patients, grown into organoids, modified by gene-editing techniques, and then returned to the patient as a transplantation procedure. The feasibility of this approach has been proved in animal experiments, but not yet in humans. Many are hopeful the use of organoids can reduce our dependence on animal research in coming years.
The pace of organoid research is escalating dramatically, along with excitement about its potential. A recent commentary on the study of brain diseases using organoids was titled “Psychiatry in a Dish.” This kind of far-fetched thinking shows where the field is leaning.
The technology probably will not be ready for use in clinics or hospitals for many years. In the meantime, we will learn a great deal of basic scientific knowledge. Ultimately, these early days will likely prove to be the pioneering era leading to our ability to grow completely formed human organs for medical purposes.
I also can imagine a future in which unexplained symptoms or a new disease diagnosis prompts development of a bank of personal organoids for use in laboratory testing. These mini-me or mini-you organoids will then be used to establish a diagnosis or to design the best possible treatment, fulfilling the promise of precision medicine.