3D cultures grow cells into aggregates/spheroids using matrix-based or matrix free techniques
Morphology of a 3D aggregate
A hallmark advancement in cell culture techniques has been the establishment of three-dimensional (3D) culture systems. They are some of the fast-growing experimental approaches in life sciences. The fundamental advantage of this culture technique is that it helps in enabling practical analysis by relating its structure to in vivo function. 3D cultures grow cells into aggregates/spheroids using matrix-based or matrix free techniques. With each of these methods, aggregates are generated in a 3D environment by allowing the cells to interact with each other, the extra cellular matrix (ECM) and their microenvironment. These interactions established in 3D cultures resemble the microenvironment found in vivo and hence the 3D aggregate morphology closely imitate its native shape in the body. The cell-cell and cell-ECM interactions in such 3D spatial arrangement affect the cellular functions such as morphology, cell proliferation, differentiation, protein and gene expression and cellular responses to external factors.
3D aggregates generally have a diameter of 200 micrometres or more with a spherical shape. They consist of cells in various stages such as proliferating, non-proliferating and necrotic cells. The outer layer of the aggregate consists of proliferating cells because they are highly exposed to the medium. The cells in the middle and the inner layers receive less oxygen, growth factors and nutrients from the medium and hence consist of non-proliferating and necrotic cells. Such cellular heterogeneity is closely similar to in vivo environment. One of the primary features as induced by the 3D culture systems is the spontaneous formation of distinct morphology of the cells. The morphological appearance is usually cell-line dependant. The aggregates form round, mass, grape-like or stellate structures depending on the type of 3D model utilized. Since the morphology and the interactions established in 3D cultures resemble in vivo, the cellular processes of the cells also mimic the in vivo conditions. 3D culture systems aid in providing outstanding in vitro models to understand and study the cellular responses of the spheroids that closely reflects in vivo environment in an in vitro setting. Thus, 3D culture systems are excellent relevance to biological system and play invaluable role as excellent in vitro research models.
Author details: Ms. Arokia Femina is pursuing her MSc in Human Genetics at the Department of Human Genetics, Faculty of Biomedical Science, Sri Ramachandra Institute of Higher Education and Research, Chennai – 600116, India. E-Mail ID: firstname.lastname@example.org