2D cell culture has been around since the early 20th century and has been recognised traditionally as a successful method for growing simple cells. However, 3D printing and the advances this has brought over recent years to progress 3D cell culture capabilities is attracting far more attention from scientists.
Do they both have an essential part to play? With the help of providers of 2D and 3D peptide hydrogels and bioinks used in cell culture and 3D bioprinting, we look at the difference between 2D and 3D cell culture. We examine how they are different and why they are forging ahead, supporting the development of 3D cell culture systems.
2D cell culture
Most cell culture research using 2D cell cultures is easy to set up and analyse, so it is seen as a proven approach for most current routine assays. 2D cell cultures consist of cells grown in flat plastic dishes. Economies of scale mean they are relatively low cost, allowing for high scale testing. The plentiful availability of literature enables scientists to quickly and readily compare results. The tests have been in use for so long there is a long and valuable history. It is also a method familiar to anyone involved in cell culture, which is universally understood and widely used. For some culture tests, results are more clearly observed and analysed than some 3D cell culture systems.
Reading above makes you wonder what place 3D cell culture has or why it is needed if all is well within the existing 2D cell culture test capability. So we now look at the disadvantages of 2D cell culture to see why 3D cell culture is gaining hugely in popularity in recent years.
The extensive use of 2D cell culture has identified some apparent shortfalls in its suitability in some areas. It is not representative of the in vivo environment, making reliable predictions for human clinical trials impossible. It involves cells growing on a flat surface as a monolayer, making it difficult to understand the behaviour of cells and their function surrounded by three-dimensional cells in a human body. They produce a volume of waste, dead cells and can damage the environment the cells are in. These limitations make 2D cell culture less able to predict outcomes, meaning a failure rate and cost for clinical trials and drug discovery that causes losses for pharmaceutical companies on failed drugs.
3D cell culture may better represent tissue outside the human body
3D cell cultures are more physiologically relevant and predictive. They retain homeostasis longer, better representing structural cell complexity. 3D cells can interact by creating linked complex systems to model better how different cell types interact. Cells need to integrate fluid flow, something crucial for tissue function, which is achievable through metabolic 3D cell culture adaptation.
3D cell culture better simulates the conditions of a living human organ. The ability to mimic diseased tissue has led to advances in understanding the mechanism of cancer tumours as 3D cell culture systems will grow similarly and allow treatment pattern predictions. This has reduced the need for animal testing, helping drug discovery and testing meet the demands to reduce the number of animals used to bring a drug or medical procedure to the market.
Scaffold and scaffold-free systems are available. However, the most focus remains on systems requiring a 3D hydrogel scaffold for cells to grow in three dimensions to provide the extracellular matrix (ECM) for the cells to survive and proliferate.
Conclusion
It’s clear that 3D cell culture systems have a significant and growing contribution to make to the future of testing without using animals, the ability to link 3D bioprinting to replicate and reproduce human tissue and organs for regenerative and predictive medicine.
We may well see an end to 2D culture as we learn and achieve more using 3D cell culture systems.