For a long time, scientists have relied on flat 2D cell cultures grown on a plate to study cellular and disease mechanisms. 2D cell models are simple and cost-effective to culture and process. Within the last decade, however, 3D cell cultures have become increasing popular because they are more physiologically relevant and better represent in vivo tissue. If you think about it, no cell types within our body grow as a monolayer independent of other cells or tissue. Instead, most cells naturally exist in complex 3D structures including different cell types within an extracellular matrix. The numerous cell-cell and cell-matrix interactions all have a profound effect on their behavior. In addition, 2D monolayers have uniform access to nutrients and oxygen, which is not the case in cell masses, such as tumors. 3D tumor spheroids are much more representative of in vivo tumors in which inner cells have less access to nutrients and oxygen compared to the outer layer, forming a natural gradient.
Here are some reasons to use 3D cell cultures:
- 3D cultures better mimic tissue-like structures
- Able to exhibit differentiated cellular function
- Possible to co-culture two or more different cell types
- Can simulate microenvironment conditions such as hypoxia and nutrient gradients
- Better predict in vivo responses to drug treatment