Three-Dimensional Vascularized Lung Cancer-on-a-Chip with Lung Extracellular Matrix Hydrogels for In Vitro Screening

SIMPLE SUMMARY: The development of three-dimensional in vitro screening tools that mimic the microenvironment of human organs is crucial to understand the mechanism and efficacy of anti-cancer drugs in the human body. In this study, we used three strategies to engineer a three-dimensional vascularized lung cancer-on-a-chip (VLCC) to mimic the in vivo cellular microenvironment. We induced sprouting angiogenesis in the VLCC to form large blood vessels similar in size to arterioles. Additionally, we used a lung decellularized extracellular matrix to mimic the mechanical and biochemical properties of native lung tissues having various proteins and cytokines. Finally, we used tumor spheroids to mimic a solid type of lung cancer. Our drug screening tests revealed that the VLCC is a more effective tool to investigate mechanisms of drug action and their efficacies than 2D platforms. The VLCC developed in this study will improve our understanding of the effects of drug screening on the tumor environment. ABSTRACT: Recent advances in immunotherapies and molecularly targeted therapies have led to an increased interest in exploring the field of in vitro tumor mimetic platforms. An increasing need to understand the mechanisms of anti-cancer therapies has led to the development of natural tumor tissue-like in vitro platforms capable of simulating the tumor microenvironment. The incorporation of vascular structures into the in vitro platforms could be a crucial factor for functional investigation of most anti-cancer therapies, including immunotherapies, which are closely related to the circulatory system. Decellularized lung extracellular matrix (ldECM), comprised of ECM components and pro-angiogenic factors, can initiate vascularization and is ideal for mimicking the natural microenvironment. In this study, we used a ldECM-based hydrogel to develop a 3D vascularized lung cancer-on-a-chip (VLCC). We specifically encapsulated tri-cellular spheroids made from A549 cells, HUVECs, and human lung fibroblasts, for simulating solid type lung cancer. Additionally, two channels were incorporated in the hydrogel construct to mimic perfusable vessel structures that resemble arterioles or venules. Our study highlights how a more effective dose-dependent action of the anti-cancer drug Doxorubicin was observed using a VLCC over 2D screening. This observation confirmed the potential of the VLCC as a 3D in vitro drug screening tool.