For years, cell cultures have made it possible to maintain specific types of cells in the laboratory to study their physiology and the diseases developed when there are abnormalities.
But if we think of the natural state of cells within an organ, where they are organized in three dimensions forming tissues and interacting with other cell types, a monolayer of cells cultured in the laboratory is far from reality.
For this reason, attempts have long been made to cultivate organoids: three-dimentional structures formed thanks to the cells’ capacity for aggregation and self-organization, and which emulate small organs.
Organoids are three-dimensional cellular structures created in the laboratory to emulate organs.
The diversity of miniature organs
There are many types of organoids – as many as organs in our body – but we can roughly distinguish them according to their origin:
- Organoids derived from adult stem cells in tissues that can regenerate. These can be cultivated for a long time under the right culture conditions. Examples of these are the organoids of the intestine or liver.
- Organoids derived from pluripotent cells, which therefore require a differentiation process. These have a limited life in culture and the best known are the brain organoids.
A step forward, but not definitive
Knowing how a given cell behaves when it is in contact with other types of cells and receives information from them, allows us to obtain results closer to those of in vivo studies carried out with patients or model organisms. Therefore, the use of organoids represents a partial alternative to the use of animals for experimentation and shortens the path of translational research.
At the Barcelona Biomedical Research Park (PRBB) there are different groups working with organoids, cultivating miniature brain, eye or lung cells. But in all cases, the life of these organoids is limited by their difficulty to generate vasculature and, therefore, to have a good transport of oxygen and nutrients, as well as to eliminate metabolic waste.
To overcome these limitations, new techniques such as fluidics or tissue culture on chip should be applied. Alternatives that are already being integrated in the experiments carried out in the PRBB, but that we still do not find in the daily routine of the laboratories.