3D cancer spheroids and microtissues

The biomaterials-based three-dimensional (3D) cancer models enhance the investigation of the mechanisms underpinning the cancer progression and metastasis. In vitro 3D tumor models could substitute the use of two-dimensional cell culture and reduce the number of animals recruited for the preclinical trials of anticancer drug. Moreover, pharmaceutical companies are adopting 3D cancer models as platform for anticancer drug testing platforms. The spheroid is the gold standard for the drug screening 3D platform due to its easy handling and low cost. However, spheroids composed only with cancer cells, are not able to copy entirely the complexity of the tumor microenvironment (TME) due to the lack of expression of the extracellular matrix (ECM) proteins. On the other hand, tumor models based on microcarriers exhibit physiologically relevant cell-cell and cell-matrix interactions. In this perspective, biomaterials can be used as ECM substitute to mimic the cell-ECM interaction and structural complexity in order to reflect in vivo tumors. In this chapter, we focus on the different players of the TME such as cancer cells, fibroblasts, endothelial, and immune system cells. For each paragraph, the most interesting 3D tumor models (both spheroids- and microcarriers-based cancer models) are described in order to give an updated state-of-the-art overview of the field.