Table 2.

Comparison between 2D versus 3D cell cultures: Advantages and disadvantages.

Type of System	Description	Advantages	Disadvantages
2D cell cultures	Cells grow on flat dishes, regularly made of plastic, where they adhere and spread until they reach confluence.	Inexpensive Ease of observing cells for interpretation Cells can be easily extracted from the medium and used for further experiments Most frequently used method in laboratories	Are not representative of real cellular environments Consist of individual dispersed cells Loss of the original tissue’s heterogeneity Lack of nutrients and oxygen gradients Homogeneous exposition to nutrients and to drugs Lack of ECM–cell interactions and signaling activated by the substrate
3D cell cultures
Spheroids	Spheroids grow over plastic surfaces forming floating 3D structures in which the cells form various layers which mimic some of the physical and biochemical features of solid tumor masses.	Can better to mimic a tumor mass Better at recreating the cell–cell interactions in different types of tumor cells Establishment of barriers between tissues Formation of nutrients and oxygen nutrients	More expensive and time- consuming Few commercially available Lack of nutrients at the core of spheroids affecting cell viability Lack of ECM–cell interactions and signaling activated by the substrate’s compounds
Organotypic cell cultures in scaffolds	A 3D scaffold provides a way for cells to grow in three dimensions on a 3D plate. It has the ability to mimic the microenvironment in vivo more closely. These are typically provided through biomaterials of animal or vegetable origin called “hydrogels” as an ECM in which cells can survive, grow, and proliferate.	Can be accurately grown and measured An ideal environment for drug discovery and development The high levels of viability in cells can promote cell–cell and cell–ECM interactions and further affect the cells’ shape, metabolism, function, migration, proliferation, differentiation, and adhesion	Natural ECM has poor mechanical properties High sensitivity to enzymes, which limits its potential for application Scaffolds and the topography of cell distribution may cause various behaviors of the cell Microscopic cell observations and cell extraction are restricted for some analyses
Organoids	The reason for growth in 3D organoid cell cultures is that it is simply a better way of representing human tissues outside the body.	Organoids are a more realistic way to grow and treat cells, imitating the architecture of the parental tissues They are suitable for gene editing and used for simulating host–microbe interactions They can self-renew and maintain the physiological structure and function of tissues Creation of organoid biobanks becomes possible and, in this way, reduces the use of animal models	More time-consuming and very expensive Lack of high-fidelity cell types The limited maturation, atypical physiology, and lack of realization are features that may limit their reliability for certain applications