Biomimetic Three Dimensional Cell Culturing: Colorectal Cancer Micro-Tissue Engineering

Abstract : Background: Spheroid cultures are known to mimic closely the properties of tumor tissue than monolayer cultures with regard to growth kinetics and metabolic rates. The aim of this paper is to confirm that tumor micro-tissue in a 3D biocompatible microenvironment maintain the cells natural behavior when compared to 2D monolayer culturing. Method: In order to validate our 3D culture system, we compared the 3D culture within a cross-linked hydrogel of hyaluronic acid, one of the major components of the extracellular matrix and the conventional 2D culture system. Results: Interestingly within our culture system, cells could be analyzed either after retrieval from the scaffold or even without being extracted in the 3D form rendering the HA hydrogel an ideal tool for biological applications. We observed the difference in the cell cycle, cell proliferation and behavior in both culture systems. Additionally drug testing was carried out using a chemotherapeutic agent (cis-platinium) that is already in clinical use to unequivocally prove the clinical predictive significance of the test strategy as compared with less complex assay systems and more complex in vivo models. We observed the presence of cell cycle heterogeneity very similar to the situation in vivo human tumors. Moreover, we have confirmed that resistance to chemotherapeutic reagents within this 3D culture system is much higher than those used in 2D cultures, since the tight assembly of cells in 3D culture systems render them more resistant requiring chemotherapeutic doses that recapitulate the drug sensitivity of tumor cells in vivo. Additionally we have observed the difference of apoptotic protein expression between 2D and 3D cell culture.