Tumor microenvironment-dependent maturation of hepatocarcinoma cells spheroids formed within microfluidics-generated 3D microgels for chemotherapeutics testing

Abstract

Tumor tissue models have been highlighted as a platform to investigate tumor physiologies such as progression, proliferation, vascularization, and maturation as well as chemotherapeutics screening and sensitivity testing. Among multiple factors to determine tumor spheroid fate, the importance of microenvironmental factors such as extracellular matrix is well recognized but has not been widely investigated. Here, the different subtype of hepatocarcinoma cell (HCC) spheroids was formed and matured within an even size of microgel fabricated by flow-focusing microfluidics device. Microgel was designed to control its physical and biochemical properties for changes in the tumor microenvironment. Stiffness around HCC was controlled in a wide range by polymer concentration. In addition, hyaluronic acid, composed of liver extracellular matrix as bioactive glycosaminoglycans, was added to the microgel to investigate HCC spheroid fate depending on stiffness and biomaterial composition. Their influence on tumor physiology and maturation was exhibited to be highly dependent on cell subtype, HEPG2, and HEP3B cell line. Using these spheroids, chemotherapeutic screening was performed to confirm various chemoresistance effects for each cell subtype, resulting from the different microenvironments guidance.