Multicellular tumor spheroid on a chip with functional vessel perfusion

Abstract

Cancer is one of the brutal cause of death worldwide. Fortunately, the rise of the microfluidic system sheds light on the in-vitro platform recapitulating the in-vivo microenvironment. Here, we present an on-chip vascularized multicellular tumor spheroid(MCTS) model composed of tumor cells, stromal cells, and vascular endothelial cells that are constructed for mimicking pathophysiological relevant in-vitro 3D microtumor model. Three different cell types including human liver cancer cell (HepG2), human umbilical vascular endothelial cell (HUVEC), human fibroblast (IMR90) are assembled together forming MCTS within 24 hours. The cellular ratio in the MCTS is assessed by uorescent imaging as each cell types are pre-labeled with different colors. The PDMS microfluidic device is obtained from 3D printed PC-like mold. The MCTSs are introduced to microfluidic channel along with endothelial cells and co-cultured for 4 days. Vascular endothelial cells anastomosed and formed a vascular network together with MCTS inside the microfluidic device within 4 days. Perfusion of the microbeads shows a lumenized functional vascular bed has formed. Immunofluorescence staining of vascular endothelial marker CD31 displayed the positive formation of cell-to-cell junctions. We also compare vascular ermeability between the MCTS of distinct cell types for exploring the impaired barrier function that is considered as a unique feature of tumor vasculature. Notably, we have shown that MCTS containing all three cell types resulted in the most prominent growth pattern while vascular permeability and basement membrane intensity were comparable with different cases. The microfluidic tumor vasculature model, capable of monitoring dynamic drug delivery, have potential to suggesting personalized medical strategies according to the implementation of patient-specific microenvironment.