The construction of in vitro tumor models based on 3D bioprinting

Abstract

Cancer is characterized by a high fatality rate, complex molecular mechanism, and costly therapies. The microenvironment of a tumor consists of multiple biochemical cues and the interaction between tumor cells, stromal cells, and extracellular matrix plays a key role in tumor initiation, development, angiogenesis, invasion and metastasis. To better understand the biological features of tumor and reveal the critical factors of therapeutic treatments against cancer, it is of great significance to build in vitro tumor models that could recapitulate the stages of tumor progression and mimic tumor behaviors in vivo for efficient and patient-specific drug screening and biological studies. Since conventional tissue engineering methods of constructing tumor models always fail to simulate the later stages of tumor development due to the lack of ability to build complex structures and angiogenesis potential, three-dimensional (3D) bioprinting techniques have gradually found its applications in tumor microenvironment modeling with accurate composition and well-organized spatial distribution of tumor-related cells and extracellular components in the past decades. The capabilities of building tumor models with a large range of scale, complex structures, multiple biomaterials and vascular network with high resolution and throughput make 3D bioprinting become a versatile platform in bio-manufacturing as well as in medical research. In this review, we will focus on 3D bioprinting strategies, design of bioinks, current 3D bioprinted tumor models in vitro classified with their structures and propose future perspectives.