In vitro 3D cocultured tumor-vascular barrier model based on alginate hydrogel and Transwell system for anti-cancer drug evaluation.

The development of three-dimensional (3D) in vitro model to recapitulate the in vivo tumor tissue is essential for studying tumor biology, discovering anti-cancer drugs, and evaluating anti-cancer drug efficacy. However, most of the previous models lack the involvement of vascular barrier. Here, we proposed an in vitro 3D cocultured tumor-vascular barrier model by the combination of alginate hydrogels beads and Transwell system. PC-3 cells and NIH/3T3 cells were encapsulated in alginate hydrogel beads, which were cultured in the bottom chamber of Transwell, while human umbilical vein endothelial cells (HUVECs) were cultured on the porous membrane in the upper chamber to form vascular barrier. The effect of the concentration of alginate sodium on the morphology, diameter and swelling ratio of the beads was studied. The alginate sodium content and cell seeding density were further optimized according to cell proliferation ability. The formation of endothelial barrier was verified by immunostaining with tight junction protein VE-cadherin and transendothelial electrical resistance (TEER) monitoring. Finally, the drug response of 3D cocultured tumor-vascular barrier model to curcumin was evaluated. Compared with two-dimensional (2D) coculture model and 3D coculture spheroid model, 3D tumor-vascular barrier model showed the highest activity of cancer cells and the strongest drug resistance. The developed 3D cocultured tumor-vascular barrier model possesses great potential to be applied for in vitro evaluation of anti-tumor drugs.