Fig. 2
From: Modeling neoplastic disease with spheroids and organoids
Spheroid model. a Schematic representation of spheroid variation in shape and size over time. b Main characteristics of spheroid model. The spheroid is composed of several functionally differentiated areas and layers resulting from the impaired distribution of nutrients and oxygen. Tumor cells composing the spheroids interact with each other, developing a well-organized spatial architecture characterized by differences in phenotypic, functional, and metabolic status.