Colorectal Cancer Bioengineered Microtissues as a Model to Replicate Tumor-ECM Crosstalk and Assess Drug Delivery Systems In Vitro

Current 3D cancer models (in vitro) fail to reproduce complex cancer cell extracellular matrices (ECMs) and the interrelationships occurring (in vivo) in the tumor microenvironment (TME). Herein, we propose 3D in vitro colorectal cancer microtissues (3D CRC mu Ts), which reproduce the TME more faithfully in vitro. Normal human fibroblasts were seeded onto porous biodegradable gelatin microbeads (GPMs) and were continuously induced to synthesize and assemble their own ECMs (3D Stroma mu Ts) in a spinner flask bioreactor. Then, human colon cancer cells were dynamically seeded onto the 3D Stroma mu Ts to achieve the 3D CRC mu Ts. Morphological characterization of the 3D CRC mu Ts was performed to assess the presence of different complex macromolecular components that feature in vivo in the ECM. The results showed the 3D CRC mu Ts recapitulated the TME in terms of ECM remodeling, cell growth, and the activation of normal fibroblasts toward an activated phenotype. Then, the microtissues were assessed as a drug screening platform by evaluating the effect of 5-Fluorouracil (5-FU), curcumin-loaded nanoemulsions (CT-NE-Curc), and the combination of the two. When taken together, the results showed that our microtissues are promising in that they can help clarify complex cancer-ECM interactions and evaluate the efficacy of therapies. Moreover, they may be combined with tissue-on-chip technologies aimed at addressing further studies in cancer progression and drug discovery.

Automated summary

In this study, a three-dimensional in vitro colorectal cancer microtissue model was proposed to better replicate the tumor microenvironment. Normal human fibroblasts were cultured on porous gelatin microbeads to generate their own extracellular matrices, followed by seeding of human colon cancer cells to form the microtissues. Morphological characterization confirmed the presence of complex macromolecular components and the recapitulation of the tumor microenvironment. Furthermore, the microtissues were evaluated as a drug screening platform, showing promise in assessing the efficacy of various therapies.